Merge branch 'master' of ssh://gerrit.onlab.us:29418/onos-next

Conflicts:
	core/net/src/main/java/org/onlab/onos/net/device/impl/DeviceManager.java
	core/store/hz/cluster/src/main/java/org/onlab/onos/store/cluster/impl/DistributedMastershipStore.java

Change-Id: Ia1274657b27e01366a4a87196a13068d7104ee80

@@ -24,10 +24,20 @@
         </dependency>
         <dependency>
             <groupId>org.onlab.onos</groupId>
+            <artifactId>onlab-osgi</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
             <artifactId>onlab-nio</artifactId>
             <version>${project.version}</version>
         </dependency>
         <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onlab-netty</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
             <groupId>org.apache.karaf.shell</groupId>
             <artifactId>org.apache.karaf.shell.console</artifactId>
         </dependency>

@@ -11,6 +11,9 @@ import org.onlab.onos.cluster.ClusterService;
 import org.onlab.onos.net.device.DeviceEvent;
 import org.onlab.onos.net.device.DeviceListener;
 import org.onlab.onos.net.device.DeviceService;
+import org.onlab.onos.net.intent.IntentEvent;
+import org.onlab.onos.net.intent.IntentListener;
+import org.onlab.onos.net.intent.IntentService;
 import org.slf4j.Logger;
 
 import static org.slf4j.LoggerFactory.getLogger;
@@ -29,13 +32,18 @@ public class FooComponent {
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected DeviceService deviceService;
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentService intentService;
+
     private final ClusterEventListener clusterListener = new InnerClusterListener();
     private final DeviceListener deviceListener = new InnerDeviceListener();
+    private final IntentListener intentListener = new InnerIntentListener();
 
     @Activate
     public void activate() {
         clusterService.addListener(clusterListener);
         deviceService.addListener(deviceListener);
+        intentService.addListener(intentListener);
         log.info("Started");
     }
 
@@ -43,6 +51,7 @@ public class FooComponent {
     public void deactivate() {
         clusterService.removeListener(clusterListener);
         deviceService.removeListener(deviceListener);
+        intentService.removeListener(intentListener);
         log.info("Stopped");
     }
 
@@ -59,6 +68,23 @@ public class FooComponent {
             log.info("YEEEEHAAAAW! {}", event);
         }
     }
+
+    private class InnerIntentListener implements IntentListener {
+        @Override
+        public void event(IntentEvent event) {
+            String message;
+            if (event.type() == IntentEvent.Type.SUBMITTED) {
+                message = "WOW! It looks like someone has some intentions: {}";
+            } else if (event.type() == IntentEvent.Type.INSTALLED) {
+                message = "AWESOME! So far things are going great: {}";
+            } else if (event.type() == IntentEvent.Type.WITHDRAWN) {
+                message = "HMMM! Ambitions are fading apparently: {}";
+            } else {
+                message = "CRAP!!! Things are not turning out as intended: {}";
+            }
+            log.info(message, event.subject());
+        }
+    }
 }
 
 

+package org.onlab.onos.foo;
+
+import java.io.IOException;
+
+import org.onlab.netty.Message;
+import org.onlab.netty.MessageHandler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * Message handler that echos the message back to the sender.
+ */
+public class NettyEchoHandler implements MessageHandler {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    @Override
+    public void handle(Message message) throws IOException {
+        //log.info("Received message. Echoing it back to the sender.");
+        message.respond(message.payload());
+    }
+}

+package org.onlab.onos.foo;
+
+import org.onlab.netty.Message;
+import org.onlab.netty.MessageHandler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A MessageHandler that simply logs the information.
+ */
+public class NettyLoggingHandler implements MessageHandler {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    @Override
+    public void handle(Message message) {
+        //log.info("Received message. Payload has {} bytes", message.payload().length);
+    }
+}

+package org.onlab.onos.foo;
+
+import java.io.IOException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeoutException;
+
+import org.onlab.metrics.MetricsComponent;
+import org.onlab.metrics.MetricsFeature;
+import org.onlab.metrics.MetricsManager;
+import org.onlab.netty.Endpoint;
+import org.onlab.netty.NettyMessagingService;
+import org.onlab.netty.Response;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Timer;
+
+// FIXME: Should be move out to test or app
+public final class SimpleNettyClient {
+
+private static Logger log = LoggerFactory.getLogger(SimpleNettyClient.class);
+
+        private SimpleNettyClient() {
+    }
+
+    public static void main(String[] args)
+            throws IOException, InterruptedException, ExecutionException,
+            TimeoutException {
+        try {
+            startStandalone(args);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        System.exit(0);
+    }
+    public static void startStandalone(String... args) throws Exception {
+        String host = args.length > 0 ? args[0] : "localhost";
+        int port = args.length > 1 ? Integer.parseInt(args[1]) : 8081;
+        int warmup = args.length > 2 ? Integer.parseInt(args[2]) : 1000;
+        int iterations = args.length > 3 ? Integer.parseInt(args[3]) : 50 * 100000;
+        NettyMessagingService messaging = new TestNettyMessagingService(9081);
+        MetricsManager metrics = new MetricsManager();
+        messaging.activate();
+        metrics.activate();
+        MetricsFeature feature = new MetricsFeature("latency");
+        MetricsComponent component = metrics.registerComponent("NettyMessaging");
+        log.info("warmup....");
+
+        for (int i = 0; i < warmup; i++) {
+            messaging.sendAsync(new Endpoint(host, port), "simple", "Hello World".getBytes());
+            Response response = messaging
+                    .sendAndReceive(new Endpoint(host, port), "echo",
+                            "Hello World".getBytes());
+        }
+
+        log.info("measuring async sender");
+        Timer sendAsyncTimer = metrics.createTimer(component, feature, "AsyncSender");
+
+        for (int i = 0; i < iterations; i++) {
+            Timer.Context context = sendAsyncTimer.time();
+            messaging.sendAsync(new Endpoint(host, port), "simple", "Hello World".getBytes());
+            context.stop();
+        }
+
+        Timer sendAndReceiveTimer = metrics.createTimer(component, feature, "SendAndReceive");
+        for (int i = 0; i < iterations; i++) {
+            Timer.Context context = sendAndReceiveTimer.time();
+            Response response = messaging
+                    .sendAndReceive(new Endpoint(host, port), "echo",
+                                    "Hello World".getBytes());
+            // System.out.println("Got back:" + new String(response.get(2, TimeUnit.SECONDS)));
+            context.stop();
+        }
+    }
+
+    public static class TestNettyMessagingService extends NettyMessagingService {
+        public TestNettyMessagingService(int port) throws Exception {
+            super(port);
+        }
+    }
+}

+package org.onlab.onos.foo;
+
+import static org.onlab.onos.foo.SimpleNettyClient.startStandalone;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cli.AbstractShellCommand;
+
+/**
+ * Test Netty client performance.
+ */
+@Command(scope = "onos", name = "simple-netty-client",
+        description = "Starts the simple Netty client")
+public class SimpleNettyClientCommand extends AbstractShellCommand {
+
+    //FIXME: replace these arguments with proper ones needed for the test.
+    @Argument(index = 0, name = "hostname", description = "Server Hostname",
+            required = false, multiValued = false)
+    String host = "localhost";
+
+    @Argument(index = 3, name = "port", description = "Port",
+            required = false, multiValued = false)
+    String port = "8081";
+
+    @Argument(index = 1, name = "warmupCount", description = "Warm-up count",
+            required = false, multiValued = false)
+    String warmup = "1000";
+
+    @Argument(index = 2, name = "messageCount", description = "Message count",
+            required = false, multiValued = false)
+    String messageCount = "100000";
+
+    @Override
+    protected void execute() {
+        try {
+            startStandalone(new String[]{host, port, warmup, messageCount});
+        } catch (Exception e) {
+            error("Unable to start client %s", e);
+        }
+    }
+
+}

+package org.onlab.onos.foo;
+
+import org.onlab.netty.NettyMessagingService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Test to measure Messaging performance.
+ */
+    public final class SimpleNettyServer {
+        private static Logger log = LoggerFactory.getLogger(SimpleNettyServer.class);
+
+            private SimpleNettyServer() {}
+
+            public static void main(String... args) throws Exception {
+                startStandalone(args);
+                System.exit(0);
+            }
+
+        public static void startStandalone(String[] args) throws Exception {
+            NettyMessagingService server = new NettyMessagingService(8081);
+            server.activate();
+            server.registerHandler("simple", new NettyLoggingHandler());
+            server.registerHandler("echo", new NettyEchoHandler());
+        }
+    }
+

+package org.onlab.onos.foo;
+
+import static org.onlab.onos.foo.SimpleNettyServer.startStandalone;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cli.AbstractShellCommand;
+
+/**
+ * Starts the Simple Netty server.
+ */
+@Command(scope = "onos", name = "simple-netty-server",
+         description = "Starts the simple netty server")
+public class SimpleNettyServerCommand extends AbstractShellCommand {
+
+    //FIXME: Replace these with parameters for
+    @Argument(index = 0, name = "serverIp", description = "Server IP address",
+              required = false, multiValued = false)
+    String serverIp = "127.0.0.1";
+
+    @Argument(index = 1, name = "workers", description = "IO workers",
+              required = false, multiValued = false)
+    String workers = "6";
+
+    @Argument(index = 2, name = "messageLength", description = "Message length (bytes)",
+              required = false, multiValued = false)
+    String messageLength = "128";
+
+    @Override
+    protected void execute() {
+        try {
+            startStandalone(new String[]{serverIp, workers, messageLength});
+        } catch (Exception e) {
+            error("Unable to start server %s", e);
+        }
+    }
+
+}

@@ -7,6 +7,12 @@
         <command>
             <action class="org.onlab.onos.foo.TestIOServerCommand"/>
         </command>
+        <command>
+            <action class="org.onlab.onos.foo.SimpleNettyServerCommand"/>
+        </command>
+        <command>
+            <action class="org.onlab.onos.foo.SimpleNettyClientCommand"/>
+        </command>
     </command-bundle>
 
 </blueprint>

@@ -26,9 +26,7 @@ import org.onlab.onos.net.packet.InboundPacket;
 import org.onlab.onos.net.packet.PacketContext;
 import org.onlab.onos.net.packet.PacketProcessor;
 import org.onlab.onos.net.packet.PacketService;
-import org.onlab.onos.net.proxyarp.ProxyArpService;
 import org.onlab.onos.net.topology.TopologyService;
-import org.onlab.packet.ARP;
 import org.onlab.packet.Ethernet;
 import org.slf4j.Logger;
 
@@ -39,6 +37,7 @@ import org.slf4j.Logger;
 public class ReactiveForwarding {
 
     private static final int TIMEOUT = 10;
+    private static final int PRIORITY = 10;
 
     private final Logger log = getLogger(getClass());
 
@@ -54,9 +53,6 @@ public class ReactiveForwarding {
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected FlowRuleService flowRuleService;
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected ProxyArpService proxyArpService;
-
     private ReactivePacketProcessor processor = new ReactivePacketProcessor();
 
     private ApplicationId appId;
@@ -64,7 +60,7 @@ public class ReactiveForwarding {
     @Activate
     public void activate() {
         appId = ApplicationId.getAppId();
-        packetService.addProcessor(processor, PacketProcessor.ADVISOR_MAX + 1);
+        packetService.addProcessor(processor, PacketProcessor.ADVISOR_MAX + 2);
         log.info("Started with Application ID {}", appId.id());
     }
 
@@ -92,16 +88,6 @@ public class ReactiveForwarding {
 
             InboundPacket pkt = context.inPacket();
             Ethernet ethPkt = pkt.parsed();
-            if (ethPkt.getEtherType() == Ethernet.TYPE_ARP) {
-                ARP arp = (ARP) ethPkt.getPayload();
-                if (arp.getOpCode() == ARP.OP_REPLY) {
-                    proxyArpService.forward(ethPkt);
-                } else if (arp.getOpCode() == ARP.OP_REQUEST) {
-                    proxyArpService.reply(ethPkt);
-                }
-                context.block();
-                return;
-            }
 
             HostId id = HostId.hostId(ethPkt.getDestinationMAC());
 
@@ -180,24 +166,24 @@ public class ReactiveForwarding {
         // We don't yet support bufferids in the flowservice so packet out first.
         packetOut(context, portNumber);
 
-        if (context.inPacket().parsed().getEtherType() == Ethernet.TYPE_IPV4) {
+
 
         // Install the flow rule to handle this type of message from now on.
         Ethernet inPkt = context.inPacket().parsed();
-            TrafficSelector.Builder builder = new DefaultTrafficSelector.Builder();
+        TrafficSelector.Builder builder = DefaultTrafficSelector.builder();
         builder.matchEthType(inPkt.getEtherType())
         .matchEthSrc(inPkt.getSourceMAC())
         .matchEthDst(inPkt.getDestinationMAC())
         .matchInport(context.inPacket().receivedFrom().port());
 
-            TrafficTreatment.Builder treat = new DefaultTrafficTreatment.Builder();
+        TrafficTreatment.Builder treat = DefaultTrafficTreatment.builder();
         treat.setOutput(portNumber);
 
         FlowRule f = new DefaultFlowRule(context.inPacket().receivedFrom().deviceId(),
-                    builder.build(), treat.build(), 0, appId, TIMEOUT);
+                builder.build(), treat.build(), PRIORITY, appId, TIMEOUT);
 
         flowRuleService.applyFlowRules(f);
-        }
+
     }
 
 }

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-apps</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-ifwd</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS simple reactive forwarding app that uses intent service</description>
+
+</project>

+package org.onlab.onos.ifwd;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.flow.DefaultTrafficSelector;
+import org.onlab.onos.net.flow.DefaultTrafficTreatment;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.intent.HostToHostIntent;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.packet.DefaultOutboundPacket;
+import org.onlab.onos.net.packet.InboundPacket;
+import org.onlab.onos.net.packet.OutboundPacket;
+import org.onlab.onos.net.packet.PacketContext;
+import org.onlab.onos.net.packet.PacketProcessor;
+import org.onlab.onos.net.packet.PacketService;
+import org.onlab.onos.net.topology.TopologyService;
+import org.onlab.packet.Ethernet;
+import org.slf4j.Logger;
+
+/**
+ * WORK-IN-PROGRESS: Sample reactive forwarding application using intent framework.
+ */
+@Component(immediate = true)
+public class IntentReactiveForwarding {
+
+    private final Logger log = getLogger(getClass());
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected TopologyService topologyService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected PacketService packetService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentService intentService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected HostService hostService;
+
+    private ReactivePacketProcessor processor = new ReactivePacketProcessor();
+
+    private static long intentId = 0x123000;
+
+    @Activate
+    public void activate() {
+        packetService.addProcessor(processor, PacketProcessor.ADVISOR_MAX + 2);
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        packetService.removeProcessor(processor);
+        processor = null;
+        log.info("Stopped");
+    }
+
+    /**
+     * Packet processor responsible for forwarding packets along their paths.
+     */
+    private class ReactivePacketProcessor implements PacketProcessor {
+
+        @Override
+        public void process(PacketContext context) {
+            // Stop processing if the packet has been handled, since we
+            // can't do any more to it.
+            if (context.isHandled()) {
+                return;
+            }
+
+            InboundPacket pkt = context.inPacket();
+            Ethernet ethPkt = pkt.parsed();
+
+            HostId srcId = HostId.hostId(ethPkt.getSourceMAC());
+            HostId dstId = HostId.hostId(ethPkt.getDestinationMAC());
+
+            // Do we know who this is for? If not, flood and bail.
+            Host dst = hostService.getHost(dstId);
+            if (dst == null) {
+                flood(context);
+                return;
+            }
+
+            // Otherwise forward and be done with it.
+            setUpConnectivity(context, srcId, dstId);
+            forwardPacketToDst(context, dst);
+        }
+    }
+
+    // Floods the specified packet if permissible.
+    private void flood(PacketContext context) {
+        if (topologyService.isBroadcastPoint(topologyService.currentTopology(),
+                                             context.inPacket().receivedFrom())) {
+            packetOut(context, PortNumber.FLOOD);
+        } else {
+            context.block();
+        }
+    }
+
+    // Sends a packet out the specified port.
+    private void packetOut(PacketContext context, PortNumber portNumber) {
+        context.treatmentBuilder().setOutput(portNumber);
+        context.send();
+    }
+
+    private void forwardPacketToDst(PacketContext context, Host dst) {
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder().setOutput(dst.location().port()).build();
+        OutboundPacket packet = new DefaultOutboundPacket(dst.location().deviceId(),
+                                                          treatment, context.inPacket().unparsed());
+        packetService.emit(packet);
+        log.info("sending packet: {}", packet);
+    }
+
+    // Install a rule forwarding the packet to the specified port.
+    private void setUpConnectivity(PacketContext context, HostId srcId, HostId dstId) {
+        TrafficSelector selector = DefaultTrafficSelector.builder().build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+
+        HostToHostIntent intent =
+                new HostToHostIntent(new IntentId(intentId++), srcId, dstId,
+                                     selector, treatment);
+
+        intentService.submit(intent);
+    }
+
+}

+/**
+ * Trivial application that provides simple form of reactive forwarding
+ * using the intent service.
+ */
+package org.onlab.onos.ifwd;

@@ -19,8 +19,10 @@
     <modules>
         <module>tvue</module>
         <module>fwd</module>
+        <module>ifwd</module>
         <module>foo</module>
         <module>mobility</module>
+        <module>proxyarp</module>
 	    <module>config</module>
     </modules>
 

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-apps</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-proxyarp</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS simple proxy arp module</description>
+
+</project>

+package org.onlab.onos.proxyarp;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.onos.ApplicationId;
+import org.onlab.onos.net.packet.PacketContext;
+import org.onlab.onos.net.packet.PacketProcessor;
+import org.onlab.onos.net.packet.PacketService;
+import org.onlab.onos.net.proxyarp.ProxyArpService;
+import org.slf4j.Logger;
+
+/**
+ * Sample reactive proxy arp application.
+ */
+@Component(immediate = true)
+public class ProxyArp {
+
+
+    private final Logger log = getLogger(getClass());
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected PacketService packetService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ProxyArpService proxyArpService;
+
+    private ProxyArpProcessor processor = new ProxyArpProcessor();
+
+    private ApplicationId appId;
+
+    @Activate
+    public void activate() {
+        appId = ApplicationId.getAppId();
+        packetService.addProcessor(processor, PacketProcessor.ADVISOR_MAX + 1);
+        log.info("Started with Application ID {}", appId.id());
+    }
+
+    @Deactivate
+    public void deactivate() {
+        packetService.removeProcessor(processor);
+        processor = null;
+        log.info("Stopped");
+    }
+
+
+    /**
+     * Packet processor responsible for forwarding packets along their paths.
+     */
+    private class ProxyArpProcessor implements PacketProcessor {
+
+        @Override
+        public void process(PacketContext context) {
+            // Stop processing if the packet has been handled, since we
+            // can't do any more to it.
+            if (context.isHandled()) {
+                return;
+            }
+
+            //handle the arp packet.
+            proxyArpService.handleArp(context);
+        }
+    }
+}
+
+

+/**
+ * Proxy Arp  application that handles arp resolution for you.
+ */
+package org.onlab.onos.proxyarp;

+package org.onlab.onos.cli;
+
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.CoreService;
+import org.onlab.onos.cluster.ClusterService;
+import org.onlab.onos.net.device.DeviceService;
+import org.onlab.onos.net.flow.FlowRuleService;
+import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.link.LinkService;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyService;
+
+/**
+ * Provides summary of ONOS model.
+ */
+@Command(scope = "onos", name = "summary",
+         description = "Provides summary of ONOS model")
+public class SummaryCommand extends AbstractShellCommand {
+
+    @Override
+    protected void execute() {
+        TopologyService topologyService = get(TopologyService.class);
+        Topology topology = topologyService.currentTopology();
+        print("version=%s, nodes=%d, devices=%d, links=%d, hosts=%d, clusters=%s, paths=%d, flows=%d, intents=%d",
+              get(CoreService.class).version().toString(),
+              get(ClusterService.class).getNodes().size(),
+              get(DeviceService.class).getDeviceCount(),
+              get(LinkService.class).getLinkCount(),
+              get(HostService.class).getHostCount(),
+              topologyService.getClusters(topology).size(),
+              topology.pathCount(),
+              get(FlowRuleService.class).getFlowRuleCount(),
+              get(IntentService.class).getIntentCount());
+    }
+
+}

+package org.onlab.onos.cli.net;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cli.AbstractShellCommand;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.flow.DefaultTrafficSelector;
+import org.onlab.onos.net.flow.DefaultTrafficTreatment;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.intent.HostToHostIntent;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.IntentService;
+
+/**
+ * Installs host-to-host connectivity intent.
+ */
+@Command(scope = "onos", name = "add-host-intent",
+         description = "Installs host-to-host connectivity intent")
+public class AddHostToHostIntentCommand extends AbstractShellCommand {
+
+    @Argument(index = 0, name = "one", description = "One host ID",
+              required = true, multiValued = false)
+    String one = null;
+
+    @Argument(index = 1, name = "two", description = "Another host ID",
+              required = true, multiValued = false)
+    String two = null;
+
+    private static long id = 0x7870001;
+
+    @Override
+    protected void execute() {
+        IntentService service = get(IntentService.class);
+
+        HostId oneId = HostId.hostId(one);
+        HostId twoId = HostId.hostId(two);
+
+        TrafficSelector selector = DefaultTrafficSelector.builder().build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+
+        HostToHostIntent intent =
+                new HostToHostIntent(new IntentId(id++), oneId, twoId,
+                                     selector, treatment);
+        service.submit(intent);
+    }
+
+}

+package org.onlab.onos.cli.net;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cli.AbstractShellCommand;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.flow.DefaultTrafficSelector;
+import org.onlab.onos.net.flow.DefaultTrafficTreatment;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.intent.Intent;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.intent.PointToPointIntent;
+import org.onlab.packet.Ethernet;
+
+/**
+ * Installs point-to-point connectivity intents.
+ */
+@Command(scope = "onos", name = "add-point-intent",
+         description = "Installs point-to-point connectivity intent")
+public class AddPointToPointIntentCommand extends AbstractShellCommand {
+
+    @Argument(index = 0, name = "ingressDevice",
+              description = "Ingress Device/Port Description",
+              required = true, multiValued = false)
+    String ingressDeviceString = null;
+
+    @Argument(index = 1, name = "egressDevice",
+              description = "Egress Device/Port Description",
+              required = true, multiValued = false)
+    String egressDeviceString = null;
+
+    private static long id = 0x7470001;
+
+    @Override
+    protected void execute() {
+        IntentService service = get(IntentService.class);
+
+        DeviceId ingressDeviceId = DeviceId.deviceId(getDeviceId(ingressDeviceString));
+        PortNumber ingressPortNumber =
+                PortNumber.portNumber(getPortNumber(ingressDeviceString));
+        ConnectPoint ingress = new ConnectPoint(ingressDeviceId, ingressPortNumber);
+
+        DeviceId egressDeviceId = DeviceId.deviceId(getDeviceId(egressDeviceString));
+        PortNumber egressPortNumber =
+                PortNumber.portNumber(getPortNumber(egressDeviceString));
+        ConnectPoint egress = new ConnectPoint(egressDeviceId, egressPortNumber);
+
+        TrafficSelector selector = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+
+        Intent intent =
+                new PointToPointIntent(new IntentId(id++),
+                                                 selector,
+                                                 treatment,
+                                                 ingress,
+                                                 egress);
+        service.submit(intent);
+    }
+
+    /**
+     * Extracts the port number portion of the ConnectPoint.
+     *
+     * @param deviceString string representing the device/port
+     * @return port number as a string, empty string if the port is not found
+     */
+    private String getPortNumber(String deviceString) {
+        int slash = deviceString.indexOf('/');
+        if (slash <= 0) {
+            return "";
+        }
+        return deviceString.substring(slash + 1, deviceString.length());
+    }
+
+    /**
+     * Extracts the device ID portion of the ConnectPoint.
+     *
+     * @param deviceString string representing the device/port
+     * @return device ID string
+     */
+    private String getDeviceId(String deviceString) {
+        int slash = deviceString.indexOf('/');
+        if (slash <= 0) {
+            return "";
+        }
+        return deviceString.substring(0, slash);
+    }
+}

+package org.onlab.onos.cli.net;
+
+import java.util.List;
+import java.util.SortedSet;
+
+import org.apache.karaf.shell.console.Completer;
+import org.apache.karaf.shell.console.completer.StringsCompleter;
+import org.onlab.onos.cli.AbstractShellCommand;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.device.DeviceService;
+
+/**
+ * ConnectPoint completer.
+ */
+public class ConnectPointCompleter implements Completer {
+    @Override
+    public int complete(String buffer, int cursor, List<String> candidates) {
+        // Delegate string completer
+        StringsCompleter delegate = new StringsCompleter();
+
+        // Fetch our service and feed it's offerings to the string completer
+        DeviceService service = AbstractShellCommand.get(DeviceService.class);
+
+        // Generate the device ID/port number identifiers
+        for (Device device : service.getDevices()) {
+            SortedSet<String> strings = delegate.getStrings();
+
+            for (Port port : service.getPorts(device.id())) {
+                strings.add(device.id().toString() + "/" + port.number());
+            }
+        }
+
+        // Now let the completer do the work for figuring out what to offer.
+        return delegate.complete(buffer, cursor, candidates);
+    }
+
+}

@@ -35,7 +35,7 @@ public class DevicesListCommand extends AbstractShellCommand {
      * @param service device service
      * @return sorted device list
      */
-    protected List<Device> getSortedDevices(DeviceService service) {
+    protected static List<Device> getSortedDevices(DeviceService service) {
         List<Device> devices = newArrayList(service.getDevices());
         Collections.sort(devices, Comparators.ELEMENT_COMPARATOR);
         return devices;

@@ -5,7 +5,7 @@ import java.util.SortedSet;
 
 import org.apache.karaf.shell.console.Completer;
 import org.apache.karaf.shell.console.completer.StringsCompleter;
-import org.onlab.onos.net.flow.FlowRule.FlowRuleState;
+import org.onlab.onos.net.flow.FlowEntry.FlowEntryState;
 
 /**
  * Device ID completer.
@@ -16,7 +16,7 @@ public class FlowRuleStatusCompleter implements Completer {
         // Delegate string completer
         StringsCompleter delegate = new StringsCompleter();
 
-        FlowRuleState[] states = FlowRuleState.values();
+        FlowEntryState[] states = FlowEntryState.values();
         SortedSet<String> strings = delegate.getStrings();
         for (int i = 0; i < states.length; i++) {
             strings.add(states[i].toString().toLowerCase());

 package org.onlab.onos.cli.net;
 
 import static com.google.common.collect.Lists.newArrayList;
+import static org.onlab.onos.cli.net.DevicesListCommand.getSortedDevices;
 
 import java.util.Collections;
 import java.util.List;
@@ -13,8 +14,8 @@ import org.onlab.onos.cli.Comparators;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.device.DeviceService;
-import org.onlab.onos.net.flow.FlowRule;
-import org.onlab.onos.net.flow.FlowRule.FlowRuleState;
+import org.onlab.onos.net.flow.FlowEntry;
+import org.onlab.onos.net.flow.FlowEntry.FlowEntryState;
 import org.onlab.onos.net.flow.FlowRuleService;
 
 import com.google.common.collect.Maps;
@@ -45,8 +46,8 @@ public class FlowsListCommand extends AbstractShellCommand {
     protected void execute() {
         DeviceService deviceService = get(DeviceService.class);
         FlowRuleService service = get(FlowRuleService.class);
-        Map<Device, List<FlowRule>> flows = getSortedFlows(deviceService, service);
-        for (Device d : flows.keySet()) {
+        Map<Device, List<FlowEntry>> flows = getSortedFlows(deviceService, service);
+        for (Device d : getSortedDevices(deviceService)) {
             printFlows(d, flows.get(d));
         }
     }
@@ -57,12 +58,13 @@ public class FlowsListCommand extends AbstractShellCommand {
      * @param service device service
      * @return sorted device list
      */
-    protected Map<Device, List<FlowRule>> getSortedFlows(DeviceService deviceService, FlowRuleService service) {
-        Map<Device, List<FlowRule>> flows = Maps.newHashMap();
-        List<FlowRule> rules;
-        FlowRuleState s = null;
+    protected Map<Device, List<FlowEntry>> getSortedFlows(DeviceService deviceService,
+                                                          FlowRuleService service) {
+        Map<Device, List<FlowEntry>> flows = Maps.newHashMap();
+        List<FlowEntry> rules;
+        FlowEntryState s = null;
         if (state != null && !state.equals("any")) {
-            s = FlowRuleState.valueOf(state.toUpperCase());
+            s = FlowEntryState.valueOf(state.toUpperCase());
         }
         Iterable<Device> devices = uri == null ? deviceService.getDevices() :
             Collections.singletonList(deviceService.getDevice(DeviceId.deviceId(uri)));
@@ -71,7 +73,7 @@ public class FlowsListCommand extends AbstractShellCommand {
                 rules = newArrayList(service.getFlowEntries(d.id()));
             } else {
                 rules = newArrayList();
-                for (FlowRule f : service.getFlowEntries(d.id())) {
+                for (FlowEntry f : service.getFlowEntries(d.id())) {
                     if (f.state().equals(s)) {
                         rules.add(f);
                     }
@@ -88,19 +90,17 @@ public class FlowsListCommand extends AbstractShellCommand {
      * @param d the device
      * @param flows the set of flows for that device.
      */
-    protected void printFlows(Device d, List<FlowRule> flows) {
-        print("Device: " + d.id());
-        if (flows == null | flows.isEmpty()) {
-            print(" %s", "No flows.");
-            return;
-        }
-        for (FlowRule f : flows) {
+    protected void printFlows(Device d, List<FlowEntry> flows) {
+        boolean empty = flows == null || flows.isEmpty();
+        print("deviceId=%s, flowRuleCount=%d", d.id(), empty ? 0 : flows.size());
+        if (!empty) {
+            for (FlowEntry f : flows) {
                 print(FMT, Long.toHexString(f.id().value()), f.state(), f.bytes(),
-                    f.packets(), f.lifeMillis(), f.priority());
+                      f.packets(), f.life(), f.priority());
                 print(SFMT, f.selector().criteria());
                 print(TFMT, f.treatment().instructions());
             }
-
+        }
     }
 
 }

+package org.onlab.onos.cli.net;
+
+import org.apache.karaf.shell.console.Completer;
+import org.apache.karaf.shell.console.completer.StringsCompleter;
+import org.onlab.onos.cli.AbstractShellCommand;
+import org.onlab.onos.net.intent.Intent;
+import org.onlab.onos.net.intent.IntentService;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.SortedSet;
+
+/**
+ * Intent ID completer.
+ */
+public class IntentIdCompleter implements Completer {
+    @Override
+    public int complete(String buffer, int cursor, List<String> candidates) {
+        // Delegate string completer
+        StringsCompleter delegate = new StringsCompleter();
+
+        // Fetch our service and feed it's offerings to the string completer
+        IntentService service = AbstractShellCommand.get(IntentService.class);
+        Iterator<Intent> it = service.getIntents().iterator();
+        SortedSet<String> strings = delegate.getStrings();
+        while (it.hasNext()) {
+            strings.add(it.next().id().toString());
+        }
+
+        // Now let the completer do the work for figuring out what to offer.
+        return delegate.complete(buffer, cursor, candidates);
+    }
+
+}

+package org.onlab.onos.cli.net;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cli.AbstractShellCommand;
+import org.onlab.onos.net.intent.Intent;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.IntentService;
+
+/**
+ * Removes host-to-host connectivity intent.
+ */
+@Command(scope = "onos", name = "remove-intent",
+         description = "Removes the specified intent")
+public class IntentRemoveCommand extends AbstractShellCommand {
+
+    @Argument(index = 0, name = "id", description = "Intent ID",
+              required = true, multiValued = false)
+    String id = null;
+
+    @Override
+    protected void execute() {
+        IntentService service = get(IntentService.class);
+
+        int radix = id.startsWith("0x") ? 16 : 10;
+        if (radix == 16) {
+            id = id.replaceFirst("0x", "");
+        }
+        IntentId intentId = new IntentId(Long.parseLong(id, radix));
+
+
+        Intent intent = service.getIntent(intentId);
+        if (intent != null) {
+            service.withdraw(intent);
+        }
+    }
+}

+package org.onlab.onos.cli.net;
+
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cli.AbstractShellCommand;
+import org.onlab.onos.net.intent.Intent;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.intent.IntentState;
+
+/**
+ * Lists the inventory of intents and their states.
+ */
+@Command(scope = "onos", name = "intents",
+         description = "Lists the inventory of intents and their states")
+public class IntentsListCommand extends AbstractShellCommand {
+
+    @Override
+    protected void execute() {
+        IntentService service = get(IntentService.class);
+        for (Intent intent : service.getIntents()) {
+            IntentState state = service.getIntentState(intent.id());
+            print("%s %s %s", intent.id(), state, intent);
+        }
+    }
+
+}

 package org.onlab.onos.cli.net;
 
+import org.apache.karaf.shell.commands.Argument;
 import org.apache.karaf.shell.commands.Command;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.Host;
@@ -7,28 +8,51 @@ import org.onlab.onos.net.device.DeviceAdminService;
 import org.onlab.onos.net.device.DeviceService;
 import org.onlab.onos.net.host.HostAdminService;
 import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.intent.Intent;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.intent.IntentState;
 
 /**
- * Wipes-out the entire network information base, i.e. devices, links, hosts.
+ * Wipes-out the entire network information base, i.e. devices, links, hosts, intents.
  */
 @Command(scope = "onos", name = "wipe-out",
          description = "Wipes-out the entire network information base, i.e. devices, links, hosts")
 public class WipeOutCommand extends ClustersListCommand {
 
+    private static final String DISCLAIMER = "Delete everything please.";
+
+    @Argument(index = 0, name = "disclaimer", description = "Device ID",
+              required = false, multiValued = false)
+    String disclaimer = null;
+
     @Override
     protected void execute() {
+        if (disclaimer == null || !disclaimer.equals(DISCLAIMER)) {
+            print("I'm afraid I can't do that!\nPlease acknowledge with phrase: '%s'",
+                  DISCLAIMER);
+            return;
+        }
+
+        print("Wiping devices");
         DeviceAdminService deviceAdminService = get(DeviceAdminService.class);
         DeviceService deviceService = get(DeviceService.class);
         for (Device device : deviceService.getDevices()) {
             deviceAdminService.removeDevice(device.id());
         }
 
+        print("Wiping hosts");
         HostAdminService hostAdminService = get(HostAdminService.class);
         HostService hostService = get(HostService.class);
         for (Host host : hostService.getHosts()) {
             hostAdminService.removeHost(host.id());
         }
-    }
-
 
+        print("Wiping intents");
+        IntentService intentService = get(IntentService.class);
+        for (Intent intent : intentService.getIntents()) {
+            if (intentService.getIntentState(intent.id()) == IntentState.INSTALLED) {
+                intentService.withdraw(intent);
+            }
+        }
+    }
 }

@@ -2,6 +2,9 @@
 
     <command-bundle xmlns="http://karaf.apache.org/xmlns/shell/v1.1.0">
         <command>
+            <action class="org.onlab.onos.cli.SummaryCommand"/>
+        </command>
+        <command>
             <action class="org.onlab.onos.cli.NodesListCommand"/>
         </command>
         <command>
@@ -56,6 +59,30 @@
                 <ref component-id="deviceIdCompleter"/>
             </completers>
         </command>
+
+        <command>
+            <action class="org.onlab.onos.cli.net.IntentsListCommand"/>
+        </command>
+        <command>
+            <action class="org.onlab.onos.cli.net.IntentRemoveCommand"/>
+            <completers>
+                <ref component-id="intentIdCompleter"/>
+            </completers>
+        </command>
+        <command>
+            <action class="org.onlab.onos.cli.net.AddHostToHostIntentCommand"/>
+            <completers>
+                <ref component-id="hostIdCompleter"/>
+            </completers>
+        </command>
+        <command>
+            <action class="org.onlab.onos.cli.net.AddPointToPointIntentCommand"/>
+            <completers>
+                <ref component-id="connectPointCompleter"/>
+                <ref component-id="connectPointCompleter"/>
+            </completers>
+        </command>
+
         <command>
             <action class="org.onlab.onos.cli.net.ClustersListCommand"/>
         </command>
@@ -94,6 +121,8 @@
     <bean id="clusterIdCompleter" class="org.onlab.onos.cli.net.ClusterIdCompleter"/>
     <bean id="roleCompleter" class="org.onlab.onos.cli.net.RoleCompleter"/>
     <bean id="hostIdCompleter" class="org.onlab.onos.cli.net.HostIdCompleter"/>
+    <bean id="intentIdCompleter" class="org.onlab.onos.cli.net.IntentIdCompleter"/>
     <bean id="flowRuleStatusCompleter" class="org.onlab.onos.cli.net.FlowRuleStatusCompleter"/>
+    <bean id="connectPointCompleter" class="org.onlab.onos.cli.net.ConnectPointCompleter"/>
 
 </blueprint>

@@ -8,7 +8,7 @@ import java.util.concurrent.atomic.AtomicInteger;
  */
 public final class ApplicationId {
 
-    private static AtomicInteger idDispenser;
+    private static final AtomicInteger ID_DISPENCER = new AtomicInteger(1);
     private final Integer id;
 
     // Ban public construction
@@ -50,10 +50,7 @@ public final class ApplicationId {
      * @return app id
      */
     public static ApplicationId getAppId() {
-        if (ApplicationId.idDispenser == null) {
-            ApplicationId.idDispenser = new AtomicInteger(1);
-        }
-        return new ApplicationId(ApplicationId.idDispenser.getAndIncrement());
+        return new ApplicationId(ApplicationId.ID_DISPENCER.getAndIncrement());
     }
 
 }

+package org.onlab.onos;
+
+/**
+ * Service for interacting with the core system of the controller.
+ */
+public interface CoreService {
+
+    /**
+     * Returns the product version.
+     *
+     * @return product version
+     */
+    Version version();
+
+}

+package org.onlab.onos;
+
+import java.util.Objects;
+
+import static java.lang.Integer.parseInt;
+
+/**
+ * Representation of the product version.
+ */
+public final class Version {
+
+    public static final String FORMAT = "%d.%d.%d.%s";
+
+    private final int major;
+    private final int minor;
+    private final int patch;
+    private final String build;
+
+    private final String format;
+
+    // Creates a new version descriptor
+    private Version(int major, int minor, int patch, String build) {
+        this.major = major;
+        this.minor = minor;
+        this.patch = patch;
+        this.build = build;
+        this.format = String.format(FORMAT, major, minor, patch, build);
+    }
+
+
+    /**
+     * Creates a new version from the specified constituent numbers.
+     *
+     * @param major major version number
+     * @param minor minod version number
+     * @param patch version patch number
+     * @param build build string
+     * @return version descriptor
+     */
+    public static Version version(int major, int minor, int patch, String build) {
+        return new Version(major, minor, patch, build);
+    }
+
+    /**
+     * Creates a new version by parsing the specified string.
+     *
+     * @param string version string
+     * @return version descriptor
+     */
+    public static Version version(String string) {
+        String[] fields = string.split("[.-]");
+        return new Version(parseInt(fields[0]), parseInt(fields[1]),
+                           parseInt(fields[2]), fields[3]);
+    }
+
+    /**
+     * Returns the major version number.
+     *
+     * @return major version number
+     */
+    public int major() {
+        return major;
+    }
+
+    /**
+     * Returns the minor version number.
+     *
+     * @return minor version number
+     */
+    public int minor() {
+        return minor;
+    }
+
+    /**
+     * Returns the version patch number.
+     *
+     * @return patch number
+     */
+    public int patch() {
+        return patch;
+    }
+
+    /**
+     * Returns the version build string.
+     *
+     * @return build string
+     */
+    public String build() {
+        return build;
+    }
+
+    @Override
+    public String toString() {
+        return format;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(format);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof Version) {
+            final Version other = (Version) obj;
+            return Objects.equals(this.format, other.format);
+        }
+        return false;
+    }
+}

@@ -17,6 +17,7 @@ public interface MastershipService {
      * Returns the role of the local node for the specified device, without
      * triggering master selection.
      *
+     * @param deviceId the the identifier of the device
      * @return role of the current node
      */
     MastershipRole getLocalRole(DeviceId deviceId);

+package org.onlab.onos.net;
+
+public final class AnnotationsUtil {
+
+    public static boolean isEqual(Annotations lhs, Annotations rhs) {
+        if (lhs == rhs) {
+            return true;
+        }
+        if (lhs == null || rhs == null) {
+            return false;
+        }
+
+        if (!lhs.keys().equals(rhs.keys())) {
+            return false;
+        }
+
+        for (String key : lhs.keys()) {
+            if (!lhs.value(key).equals(rhs.value(key))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    // not to be instantiated
+    private AnnotationsUtil() {}
+}

@@ -51,6 +51,22 @@ public class ConnectPoint {
     }
 
     /**
+     * Returns the identifier of the infrastructure device if the connection
+     * point belongs to a network element which is indeed an end-station host.
+     *
+     * @return network element identifier as a host identifier
+     * @throws java.lang.IllegalStateException if connection point is not
+     *                                         associated with a host
+     */
+    public HostId hostId() {
+        if (elementId instanceof HostId) {
+            return (HostId) elementId;
+        }
+        throw new IllegalStateException("Connection point not associated " +
+                                                "with an end-station host");
+    }
+
+    /**
      * Returns the connection port number.
      *
      * @return port number

@@ -73,31 +73,63 @@ public final class DefaultAnnotations implements SparseAnnotations {
     }
 
     /**
-     * Convert Annotations to DefaultAnnotations if needed and merges.
+     * Creates the union of two given SparseAnnotations.
+     * Unlike the {@link #merge(DefaultAnnotations, SparseAnnotations)} method,
+     * result will be {@link SparseAnnotations} instead of {@link Annotations}.
      *
-     * @see #merge(DefaultAnnotations, SparseAnnotations)
+     * A key tagged for removal will remain in the output SparseAnnotations,
+     * if the counterpart of the input does not contain the same key.
      *
      * @param annotations       base annotations
      * @param sparseAnnotations additional sparse annotations
      * @return combined annotations or the original base annotations if there
      * are not additional annotations
      */
-    public static DefaultAnnotations merge(Annotations annotations,
+    public static SparseAnnotations union(SparseAnnotations annotations,
                                           SparseAnnotations sparseAnnotations) {
+
+        if (sparseAnnotations == null || sparseAnnotations.keys().isEmpty()) {
+            return annotations;
+        }
+
+        final HashMap<String, String> newMap;
         if (annotations instanceof DefaultAnnotations) {
-            return merge((DefaultAnnotations) annotations, sparseAnnotations);
+            newMap = copy(((DefaultAnnotations) annotations).map);
+        } else {
+            newMap = new HashMap<>(annotations.keys().size() +
+                                   sparseAnnotations.keys().size());
+            putAllSparseAnnotations(newMap, annotations);
+        }
+
+        putAllSparseAnnotations(newMap, sparseAnnotations);
+        return new DefaultAnnotations(newMap);
     }
 
-        DefaultAnnotations.Builder builder = DefaultAnnotations.builder();
-        for (String key : annotations.keys()) {
-            builder.set(key, annotations.value(key));
+    // adds the key-values contained in sparseAnnotations to
+    // newMap, if sparseAnnotations had a key tagged for removal,
+    // and corresponding key exist in newMap, entry will be removed.
+    // if corresponding key does not exist, removal tag will be added to
+    // the newMap.
+    private static void putAllSparseAnnotations(
+                            final HashMap<String, String> newMap,
+                            SparseAnnotations sparseAnnotations) {
+
+        for (String key : sparseAnnotations.keys()) {
+            if (sparseAnnotations.isRemoved(key)) {
+                if (newMap.containsKey(key)) {
+                    newMap.remove(key);
+                } else {
+                    newMap.put(key, Builder.REMOVED);
+                }
+            } else {
+                String value = sparseAnnotations.value(key);
+                newMap.put(key, value);
+            }
         }
-        return merge(builder.build(), sparseAnnotations);
     }
 
     @Override
     public Set<String> keys() {
-        // TODO: unmodifiable to be removed after switching to ImmutableMap;
         return Collections.unmodifiableSet(map.keySet());
     }
 
@@ -115,7 +147,7 @@ public final class DefaultAnnotations implements SparseAnnotations {
     @SuppressWarnings("unchecked")
     private static HashMap<String, String> copy(Map<String, String> original) {
         if (original instanceof HashMap) {
-            return (HashMap) ((HashMap) original).clone();
+            return (HashMap<String, String>) ((HashMap<?, ?>) original).clone();
         }
         throw new IllegalArgumentException("Expecting HashMap instance");
     }

@@ -3,6 +3,7 @@ package org.onlab.onos.net;
 import org.onlab.onos.net.provider.ProviderId;
 
 import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Default edge link model implementation.
@@ -18,7 +19,7 @@ public class DefaultEdgeLink extends DefaultLink implements EdgeLink {
      * @param providerId   provider identity
      * @param hostPoint    host-side connection point
      * @param hostLocation location where host attaches to the network
-     * @param isIngress    true to indicated host-to-network direction; false
+     * @param isIngress    true to indicate host-to-network direction; false
      *                     for network-to-host direction
      * @param annotations  optional key/value annotations
      */
@@ -42,4 +43,24 @@ public class DefaultEdgeLink extends DefaultLink implements EdgeLink {
     public HostLocation hostLocation() {
         return hostLocation;
     }
+
+    /**
+     * Creates a phantom edge link, to an unspecified end-station. This link
+     * does not represent any actually discovered link stored in the system.
+     *
+     * @param edgePort  network edge port
+     * @param isIngress true to indicate host-to-network direction; false
+     *                  for network-to-host direction
+     * @return new phantom edge link
+     */
+    public static DefaultEdgeLink createEdgeLink(ConnectPoint edgePort,
+                                                 boolean isIngress) {
+        checkNotNull(edgePort, "Edge port cannot be null");
+        HostLocation location = (edgePort instanceof HostLocation) ?
+                (HostLocation) edgePort : new HostLocation(edgePort, 0);
+        return new DefaultEdgeLink(ProviderId.NONE,
+                                   new ConnectPoint(HostId.NONE, PortNumber.P0),
+                                   location, isIngress);
+    }
+
 }

@@ -10,6 +10,14 @@ import java.net.URI;
  */
 public final class HostId extends ElementId {
 
+    private static final String NIC = "nic";
+
+    /**
+     * Represents either no host, or an unspecified host; used for creating
+     * open ingress/egress edge links.
+     */
+    public static final HostId NONE = hostId(NIC + ":none-0");
+
     // Public construction is prohibited
     private HostId(URI uri) {
         super(uri);
@@ -43,8 +51,7 @@ public final class HostId extends ElementId {
      * @return host identifier
      */
     public static HostId hostId(MacAddress mac, VlanId vlanId) {
-        // FIXME: use more efficient means of encoding
-        return hostId("nic" + ":" + mac + "-" + vlanId);
+        return hostId(NIC + ":" + mac + "-" + vlanId);
     }
 
     /**

@@ -22,6 +22,17 @@ public class HostLocation extends ConnectPoint {
     }
 
     /**
+     * Creates a new host location derived from the supplied connection point.
+     *
+     * @param connectPoint connection point
+     * @param time         time when detected, in millis since start of epoch
+     */
+    public HostLocation(ConnectPoint connectPoint, long time) {
+        super(connectPoint.deviceId(), connectPoint.port());
+        this.time = time;
+    }
+
+    /**
      * Returns the time when the location was established, given in
      * milliseconds since start of epoch.
      *

@@ -6,6 +6,7 @@ import com.google.common.base.MoreObjects;
 
 // TODO Consider renaming.
 // it's an identifier for a Link, but it's not ElementId, so not using LinkId.
+
 /**
  * Immutable representation of a link identity.
  */
@@ -43,6 +44,15 @@ public class LinkKey {
         this.dst = dst;
     }
 
+    /**
+     * Creates a link identifier for the specified link.
+     *
+     * @param link link descriptor
+     */
+    public LinkKey(Link link) {
+        this(link.src(), link.dst());
+    }
+
     @Override
     public int hashCode() {
         return Objects.hash(src(), dst);

@@ -9,6 +9,8 @@ import com.google.common.primitives.UnsignedLongs;
  */
 public final class PortNumber {
 
+    public static final PortNumber P0 = portNumber(0);
+
     // TODO: revisit the max and the logical port value assignments
 
     private static final long MAX_NUMBER = (2L * Integer.MAX_VALUE) + 1;

@@ -96,4 +96,13 @@ public class DefaultDeviceDescription extends AbstractDescription
                 .toString();
     }
 
+    // default constructor for serialization
+    private DefaultDeviceDescription() {
+        this.uri = null;
+        this.type = null;
+        this.manufacturer = null;
+        this.hwVersion = null;
+        this.swVersion = null;
+        this.serialNumber = null;
+    }
 }

@@ -48,4 +48,9 @@ public class DefaultPortDescription extends AbstractDescription
         return isEnabled;
     }
 
+    // default constructor for serialization
+    private DefaultPortDescription() {
+        this.number = null;
+        this.isEnabled = false;
+    }
 }

+package org.onlab.onos.net.flow;
+
+public class CompletedBatchOperation {
+
+
+}

+package org.onlab.onos.net.flow;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import org.onlab.onos.net.DeviceId;
+import org.slf4j.Logger;
+
+public class DefaultFlowEntry extends DefaultFlowRule implements FlowEntry {
+
+    private final Logger log = getLogger(getClass());
+
+    private long life;
+    private long packets;
+    private long bytes;
+    private FlowEntryState state;
+
+    private long lastSeen = -1;
+
+
+    public DefaultFlowEntry(DeviceId deviceId, TrafficSelector selector,
+            TrafficTreatment treatment, int priority, FlowEntryState state,
+            long life, long packets, long bytes, long flowId,
+            int timeout) {
+        super(deviceId, selector, treatment, priority, flowId, timeout);
+        this.state = state;
+        this.life = life;
+        this.packets = packets;
+        this.bytes = bytes;
+        this.lastSeen = System.currentTimeMillis();
+    }
+
+    public DefaultFlowEntry(FlowRule rule, FlowEntryState state,
+            long life, long packets, long bytes) {
+        super(rule);
+        this.state = state;
+        this.life = life;
+        this.packets = packets;
+        this.bytes = bytes;
+        this.lastSeen = System.currentTimeMillis();
+    }
+
+    public DefaultFlowEntry(FlowRule rule) {
+        super(rule);
+        this.state = FlowEntryState.PENDING_ADD;
+        this.life = 0;
+        this.packets = 0;
+        this.bytes = 0;
+        this.lastSeen = System.currentTimeMillis();
+    }
+
+    @Override
+    public long life() {
+        return life;
+    }
+
+    @Override
+    public long packets() {
+        return packets;
+    }
+
+    @Override
+    public long bytes() {
+        return bytes;
+    }
+
+    @Override
+    public FlowEntryState state() {
+        return this.state;
+    }
+
+    @Override
+    public long lastSeen() {
+        return lastSeen;
+    }
+
+    @Override
+    public void setLastSeen() {
+        this.lastSeen = System.currentTimeMillis();
+    }
+
+    @Override
+    public void setState(FlowEntryState newState) {
+        this.state = newState;
+    }
+
+    @Override
+    public void setLife(long life) {
+        this.life = life;
+    }
+
+    @Override
+    public void setPackets(long packets) {
+        this.packets = packets;
+    }
+
+    @Override
+    public void setBytes(long bytes) {
+        this.bytes = bytes;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("rule", super.toString())
+                .add("state", state)
+                .toString();
+    }
+
+
+}

@@ -18,10 +18,6 @@ public class DefaultFlowRule implements FlowRule {
     private final TrafficSelector selector;
     private final TrafficTreatment treatment;
     private final long created;
-    private final long life;
-    private final long packets;
-    private final long bytes;
-    private final FlowRuleState state;
 
     private final FlowId id;
 
@@ -29,73 +25,50 @@ public class DefaultFlowRule implements FlowRule {
 
     private final int timeout;
 
+
     public DefaultFlowRule(DeviceId deviceId, TrafficSelector selector,
-            TrafficTreatment treatment, int priority, FlowRuleState state,
-            long life, long packets, long bytes, long flowId, boolean expired,
+            TrafficTreatment treatment, int priority, long flowId,
             int timeout) {
         this.deviceId = deviceId;
         this.priority = priority;
         this.selector = selector;
         this.treatment = treatment;
-        this.state = state;
+        this.timeout = timeout;
+        this.created = System.currentTimeMillis();
+
         this.appId = ApplicationId.valueOf((int) (flowId >> 32));
         this.id = FlowId.valueOf(flowId);
-        this.life = life;
-        this.packets = packets;
-        this.bytes = bytes;
-        this.created = System.currentTimeMillis();
-        this.timeout = timeout;
     }
 
     public DefaultFlowRule(DeviceId deviceId, TrafficSelector selector,
             TrafficTreatment treatement, int priority, ApplicationId appId,
             int timeout) {
-        this(deviceId, selector, treatement, priority,
-                FlowRuleState.CREATED, appId, timeout);
-    }
 
-    public DefaultFlowRule(FlowRule rule, FlowRuleState state) {
-        this(rule.deviceId(), rule.selector(), rule.treatment(),
-                rule.priority(), state, rule.id(), rule.appId(),
-                rule.timeout());
+        if (priority < FlowRule.MIN_PRIORITY) {
+            throw new IllegalArgumentException("Priority cannot be less than " + MIN_PRIORITY);
         }
 
-    private DefaultFlowRule(DeviceId deviceId,
-            TrafficSelector selector, TrafficTreatment treatment,
-            int priority, FlowRuleState state, ApplicationId appId,
-            int timeout) {
         this.deviceId = deviceId;
         this.priority = priority;
         this.selector = selector;
-        this.treatment = treatment;
-        this.state = state;
-        this.life = 0;
-        this.packets = 0;
-        this.bytes = 0;
+        this.treatment = treatement;
         this.appId = appId;
-
         this.timeout = timeout;
+        this.created = System.currentTimeMillis();
 
         this.id = FlowId.valueOf((((long) appId().id()) << 32) | (this.hash() & 0xffffffffL));
-        this.created = System.currentTimeMillis();
     }
 
-    private DefaultFlowRule(DeviceId deviceId,
-            TrafficSelector selector, TrafficTreatment treatment,
-            int priority, FlowRuleState state, FlowId flowId, ApplicationId appId,
-            int timeout) {
-        this.deviceId = deviceId;
-        this.priority = priority;
-        this.selector = selector;
-        this.treatment = treatment;
-        this.state = state;
-        this.life = 0;
-        this.packets = 0;
-        this.bytes = 0;
-        this.appId = appId;
-        this.id = flowId;
-        this.timeout = timeout;
+    public DefaultFlowRule(FlowRule rule) {
+        this.deviceId = rule.deviceId();
+        this.priority = rule.priority();
+        this.selector = rule.selector();
+        this.treatment = rule.treatment();
+        this.appId = rule.appId();
+        this.id = rule.id();
+        this.timeout = rule.timeout();
         this.created = System.currentTimeMillis();
+
     }
 
 
@@ -129,26 +102,6 @@ public class DefaultFlowRule implements FlowRule {
         return treatment;
     }
 
-    @Override
-    public long lifeMillis() {
-        return life;
-    }
-
-    @Override
-    public long packets() {
-        return packets;
-    }
-
-    @Override
-    public long bytes() {
-        return bytes;
-    }
-
-    @Override
-    public FlowRuleState state() {
-        return this.state;
-    }
-
 
     @Override
     /*
@@ -162,7 +115,7 @@ public class DefaultFlowRule implements FlowRule {
     }
 
     public int hash() {
-        return Objects.hash(deviceId, selector, id);
+        return Objects.hash(deviceId, selector, treatment);
     }
 
     @Override
@@ -179,7 +132,7 @@ public class DefaultFlowRule implements FlowRule {
         if (obj instanceof DefaultFlowRule) {
             DefaultFlowRule that = (DefaultFlowRule) obj;
             return Objects.equals(deviceId, that.deviceId) &&
-                    //Objects.equals(id, that.id) &&
+                    Objects.equals(id, that.id) &&
                     Objects.equals(priority, that.priority) &&
                     Objects.equals(selector, that.selector);
 
@@ -190,19 +143,18 @@ public class DefaultFlowRule implements FlowRule {
     @Override
     public String toString() {
         return toStringHelper(this)
-                .add("id", id)
+                .add("id", Long.toHexString(id.value()))
                 .add("deviceId", deviceId)
                 .add("priority", priority)
                 .add("selector", selector.criteria())
                 .add("treatment", treatment == null ? "N/A" : treatment.instructions())
                 .add("created", created)
-                .add("state", state)
                 .toString();
     }
 
     @Override
     public int timeout() {
-        return timeout > MAX_TIMEOUT ? MAX_TIMEOUT : this.timeout;
+        return timeout;
     }
 
 }

 package org.onlab.onos.net.flow;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Objects;
-import java.util.Set;
-
+import com.google.common.collect.ImmutableSet;
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.flow.criteria.Criteria;
 import org.onlab.onos.net.flow.criteria.Criterion;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
-import org.slf4j.Logger;
 
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+/**
+ * Default traffic selector implementation.
+ */
 public final class DefaultTrafficSelector implements TrafficSelector {
 
-    private final Set<Criterion> selector;
+    private final Set<Criterion> criteria;
 
-    private DefaultTrafficSelector(Set<Criterion> selector) {
-        this.selector = Collections.unmodifiableSet(selector);
+    /**
+     * Creates a new traffic selector with the specified criteria.
+     *
+     * @param criteria criteria
+     */
+    private DefaultTrafficSelector(Set<Criterion> criteria) {
+        this.criteria = Collections.unmodifiableSet(criteria);
     }
 
     @Override
     public Set<Criterion> criteria() {
-        return selector;
+        return criteria;
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(selector);
+        return Objects.hash(criteria);
     }
 
     @Override
@@ -40,23 +47,50 @@ public final class DefaultTrafficSelector implements TrafficSelector {
         }
         if (obj instanceof DefaultTrafficSelector) {
             DefaultTrafficSelector that = (DefaultTrafficSelector) obj;
-            return Objects.equals(selector, that.selector);
+            return Objects.equals(criteria, that.criteria);
 
         }
         return false;
     }
 
+    /**
+     * Returns a new traffic selector builder.
+     *
+     * @return traffic selector builder
+     */
+    public static TrafficSelector.Builder builder() {
+        return new Builder();
+    }
 
+    /**
+     * Returns a new traffic selector builder primed to produce entities
+     * patterned after the supplied selector.
+     *
+     * @return traffic selector builder
+     */
+    public static TrafficSelector.Builder builder(TrafficSelector selector) {
+        return new Builder(selector);
+    }
 
-    public static class Builder implements TrafficSelector.Builder {
+    /**
+     * Builder of traffic selector entities.
+     */
+    public static final class Builder implements TrafficSelector.Builder {
 
-        private final Logger log = getLogger(getClass());
+        private final Map<Criterion.Type, Criterion> selector = new HashMap<>();
 
-        private final Set<Criterion> selector = new HashSet<>();
+        private Builder() {
+        }
+
+        private Builder(TrafficSelector selector) {
+            for (Criterion c : selector.criteria()) {
+                add(c);
+            }
+        }
 
         @Override
         public Builder add(Criterion criterion) {
-            selector.add(criterion);
+            selector.put(criterion.type(), criterion);
             return this;
         }
 
@@ -107,7 +141,7 @@ public final class DefaultTrafficSelector implements TrafficSelector {
 
         @Override
         public TrafficSelector build() {
-            return new DefaultTrafficSelector(selector);
+            return new DefaultTrafficSelector(ImmutableSet.copyOf(selector.values()));
         }
 
     }

@@ -5,6 +5,7 @@ import static org.slf4j.LoggerFactory.getLogger;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Objects;
 
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.flow.instructions.Instruction;
@@ -14,10 +15,18 @@ import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 import org.slf4j.Logger;
 
+/**
+ * Default traffic treatment implementation.
+ */
 public final class DefaultTrafficTreatment implements TrafficTreatment {
 
     private final List<Instruction> instructions;
 
+    /**
+     * Creates a new traffic treatment from the specified list of instructions.
+     *
+     * @param instructions treatment instructions
+     */
     private DefaultTrafficTreatment(List<Instruction> instructions) {
         this.instructions = Collections.unmodifiableList(instructions);
     }
@@ -28,12 +37,38 @@ public final class DefaultTrafficTreatment implements TrafficTreatment {
     }
 
     /**
-     * Builds a list of treatments following the following order.
-     * Modifications -> Group -> Output (including drop)
+     * Returns a new traffic treatment builder.
      *
+     * @return traffic treatment builder
      */
+    public static TrafficTreatment.Builder builder() {
+        return new Builder();
+    }
+
+    //FIXME: Order of instructions may affect hashcode
+    @Override
+    public int hashCode() {
+        return Objects.hash(instructions);
+    }
 
-    public static class Builder implements TrafficTreatment.Builder {
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof DefaultTrafficTreatment) {
+            DefaultTrafficTreatment that = (DefaultTrafficTreatment) obj;
+            return  Objects.equals(instructions, that.instructions);
+
+        }
+        return false;
+    }
+
+    /**
+     * Builds a list of treatments following the following order.
+     * Modifications -> Group -> Output (including drop)
+     */
+    public static final class Builder implements TrafficTreatment.Builder {
 
         private final Logger log = getLogger(getClass());
 
@@ -47,6 +82,11 @@ public final class DefaultTrafficTreatment implements TrafficTreatment {
         // TODO: should be a list of instructions based on modification objects
         List<Instruction> modifications = new LinkedList<>();
 
+        // Creates a new builder
+        private Builder() {
+        }
+
+        @Override
         public Builder add(Instruction instruction) {
             if (drop) {
                 return this;

+package org.onlab.onos.net.flow;
+
+
+/**
+ * Represents a generalized match & action pair to be applied to
+ * an infrastucture device.
+ */
+public interface FlowEntry extends FlowRule {
+
+
+    public enum FlowEntryState {
+
+        /**
+         * Indicates that this rule has been submitted for addition.
+         * Not necessarily in  the flow table.
+         */
+        PENDING_ADD,
+
+        /**
+         * Rule has been added which means it is in the flow table.
+         */
+        ADDED,
+
+        /**
+         * Flow has been marked for removal, might still be in flow table.
+         */
+        PENDING_REMOVE,
+
+        /**
+         * Flow has been removed from flow table and can be purged.
+         */
+        REMOVED
+    }
+
+    /**
+     * Returns the flow entry state.
+     *
+     * @return flow entry state
+     */
+    FlowEntryState state();
+
+    /**
+     * Returns the number of milliseconds this flow rule has been applied.
+     *
+     * @return number of millis
+     */
+    long life();
+
+    /**
+     * Returns the number of packets this flow rule has matched.
+     *
+     * @return number of packets
+     */
+    long packets();
+
+    /**
+     * Returns the number of bytes this flow rule has matched.
+     *
+     * @return number of bytes
+     */
+    long bytes();
+
+    /**
+     * When this flow entry was last deemed active.
+     * @return epoch time of last activity
+     */
+    long lastSeen();
+
+    /**
+     * Sets the last active epoch time.
+     */
+    void setLastSeen();
+
+    /**
+     * Sets the new state for this entry.
+     * @param newState new flow entry state.
+     */
+    void setState(FlowEntryState newState);
+
+    /**
+     * Sets how long this entry has been entered in the system.
+     * @param life epoch time
+     */
+    void setLife(long life);
+
+    /**
+     * Number of packets seen by this entry.
+     * @param packets a long value
+     */
+    void setPackets(long packets);
+
+    /**
+     * Number of bytes seen by this rule.
+     * @param bytes a long value
+     */
+    void setBytes(long bytes);
+
+}

@@ -26,6 +26,9 @@ public final class FlowId {
         if (this == obj) {
             return true;
         }
+        if (obj == null) {
+            return false;
+        }
         if (obj.getClass()  == this.getClass()) {
             FlowId that = (FlowId) obj;
             return Objects.equal(this.flowid, that.flowid);

@@ -2,49 +2,16 @@ package org.onlab.onos.net.flow;
 
 import org.onlab.onos.ApplicationId;
 import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.intent.BatchOperationTarget;
 
 /**
  * Represents a generalized match & action pair to be applied to
  * an infrastucture device.
  */
-public interface FlowRule {
+public interface FlowRule extends BatchOperationTarget {
 
     static final int MAX_TIMEOUT = 60;
-
-    public enum FlowRuleState {
-        /**
-         * Indicates that this rule has been created.
-         */
-        CREATED,
-
-        /**
-         * Indicates that this rule has been submitted for addition.
-         * Not necessarily in  the flow table.
-         */
-        PENDING_ADD,
-
-        /**
-         * Rule has been added which means it is in the flow table.
-         */
-        ADDED,
-
-        /**
-         * Flow has been marked for removal, might still be in flow table.
-         */
-        PENDING_REMOVE,
-
-        /**
-         * Flow has been removed from flow table and can be purged.
-         */
-        REMOVED
-    }
-
-    /**
-     * Returns the flow rule state.
-     *
-     * @return flow rule state
-     */
-    FlowRuleState state();
+    static final int MIN_PRIORITY = 0;
 
     //TODO: build cookie value
     /**
@@ -92,27 +59,6 @@ public interface FlowRule {
     TrafficTreatment treatment();
 
     /**
-     * Returns the number of milliseconds this flow rule has been applied.
-     *
-     * @return number of millis
-     */
-    long lifeMillis();
-
-    /**
-     * Returns the number of packets this flow rule has matched.
-     *
-     * @return number of packets
-     */
-    long packets();
-
-    /**
-     * Returns the number of bytes this flow rule has matched.
-     *
-     * @return number of bytes
-     */
-    long bytes();
-
-    /**
      * Returns the timeout for this flow requested by an application.
      * @return integer value of the timeout
      */

+package org.onlab.onos.net.flow;
+
+import org.onlab.onos.net.flow.FlowRuleBatchEntry.FlowRuleOperation;
+import org.onlab.onos.net.intent.BatchOperationEntry;
+
+
+public class FlowRuleBatchEntry
+        extends BatchOperationEntry<FlowRuleOperation, FlowRule> {
+
+    public FlowRuleBatchEntry(FlowRuleOperation operator, FlowRule target) {
+        super(operator, target);
+    }
+
+    public enum FlowRuleOperation {
+        ADD,
+        REMOVE,
+        MODIFY
+    }
+
+}

+package org.onlab.onos.net.flow;
+
+import java.util.Collection;
+
+import org.onlab.onos.net.intent.BatchOperation;
+
+public class FlowRuleBatchOperation
+    extends BatchOperation<FlowRuleBatchEntry> {
+
+    public FlowRuleBatchOperation(Collection<FlowRuleBatchEntry> operations) {
+        super(operations);
+    }
+}

 package org.onlab.onos.net.flow;
 
+import java.util.concurrent.Future;
+
 import org.onlab.onos.ApplicationId;
+import org.onlab.onos.net.intent.BatchOperation;
 import org.onlab.onos.net.provider.Provider;
 
 /**
@@ -34,4 +37,6 @@ public interface FlowRuleProvider extends Provider {
      */
     void removeRulesById(ApplicationId id, FlowRule... flowRules);
 
+    Future<Void> executeBatch(BatchOperation<FlowRuleBatchEntry> batch);
+
 }

@@ -14,7 +14,7 @@ public interface FlowRuleProviderService extends ProviderService<FlowRuleProvide
      *
      * @param flowRule information about the removed flow
      */
-    void flowRemoved(FlowRule flowRule);
+    void flowRemoved(FlowEntry flowEntry);
 
     /**
      * Pushes the collection of flow entries currently applied on the given
@@ -22,7 +22,7 @@ public interface FlowRuleProviderService extends ProviderService<FlowRuleProvide
      *
      * @param flowRules collection of flow rules
      */
-    void pushFlowMetrics(DeviceId deviceId, Iterable<FlowRule> flowRules);
+    void pushFlowMetrics(DeviceId deviceId, Iterable<FlowEntry> flowEntries);
 
 
 

 package org.onlab.onos.net.flow;
 
+import java.util.concurrent.Future;
+
 import org.onlab.onos.ApplicationId;
 import org.onlab.onos.net.DeviceId;
 
@@ -13,6 +15,13 @@ import org.onlab.onos.net.DeviceId;
 public interface FlowRuleService {
 
     /**
+     * Returns the number of flow rules in the system.
+     *
+     * @return flow rule count
+     */
+    int getFlowRuleCount();
+
+    /**
      * Returns the collection of flow entries applied on the specified device.
      * This will include flow rules which may not yet have been applied to
      * the device.
@@ -20,7 +29,7 @@ public interface FlowRuleService {
      * @param deviceId device identifier
      * @return collection of flow rules
      */
-    Iterable<FlowRule> getFlowEntries(DeviceId deviceId);
+    Iterable<FlowEntry> getFlowEntries(DeviceId deviceId);
 
     // TODO: add createFlowRule factory method and execute operations method
 
@@ -60,6 +69,13 @@ public interface FlowRuleService {
     Iterable<FlowRule> getFlowRulesById(ApplicationId id);
 
     /**
+     * Applies a batch operation of FlowRules.
+     *
+     * @return future indicating the state of the batch operation
+     */
+    Future<CompletedBatchOperation> applyBatch(FlowRuleBatchOperation batch);
+
+    /**
      * Adds the specified flow rule listener.
      *
      * @param listener flow rule listener
@@ -72,7 +88,4 @@ public interface FlowRuleService {
      * @param listener flow rule listener
      */
     void removeListener(FlowRuleListener listener);
-
-
-
 }

@@ -10,11 +10,19 @@ import org.onlab.onos.store.Store;
 public interface FlowRuleStore extends Store<FlowRuleEvent, FlowRuleStoreDelegate> {
 
     /**
+     * Returns the number of flow rule in the store.
+     *
+     * @return number of flow rules
+     */
+    int getFlowRuleCount();
+
+    /**
      * Returns the stored flow.
+     *
      * @param rule the rule to look for
      * @return a flow rule
      */
-    FlowRule getFlowRule(FlowRule rule);
+    FlowEntry getFlowEntry(FlowRule rule);
 
     /**
      * Returns the flow entries associated with a device.
@@ -22,7 +30,7 @@ public interface FlowRuleStore extends Store<FlowRuleEvent, FlowRuleStoreDelegat
      * @param deviceId the device ID
      * @return the flow entries
      */
-    Iterable<FlowRule> getFlowEntries(DeviceId deviceId);
+    Iterable<FlowEntry> getFlowEntries(DeviceId deviceId);
 
     /**
      * Returns the flow entries associated with an application.
@@ -30,7 +38,7 @@ public interface FlowRuleStore extends Store<FlowRuleEvent, FlowRuleStoreDelegat
      * @param appId the application id
      * @return the flow entries
      */
-    Iterable<FlowRule> getFlowEntriesByAppId(ApplicationId appId);
+    Iterable<FlowRule> getFlowRulesByAppId(ApplicationId appId);
 
     /**
      * Stores a new flow rule without generating events.
@@ -40,7 +48,8 @@ public interface FlowRuleStore extends Store<FlowRuleEvent, FlowRuleStoreDelegat
     void storeFlowRule(FlowRule rule);
 
     /**
-     * Deletes a flow rule without generating events.
+     * Marks a flow rule for deletion. Actual deletion will occur
+     * when the provider indicates that the flow has been removed.
      *
      * @param rule the flow rule to delete
      */
@@ -52,12 +61,11 @@ public interface FlowRuleStore extends Store<FlowRuleEvent, FlowRuleStoreDelegat
      * @param rule the flow rule to add or update
      * @return flow_added event, or null if just an update
      */
-    FlowRuleEvent addOrUpdateFlowRule(FlowRule rule);
+    FlowRuleEvent addOrUpdateFlowRule(FlowEntry rule);
 
     /**
-     * @param rule the flow rule to remove
+     * @param rule the flow entry to remove
      * @return flow_removed event, or null if nothing removed
      */
-    FlowRuleEvent removeFlowRule(FlowRule rule);
-
+    FlowRuleEvent removeFlowRule(FlowEntry rule);
 }

@@ -3,6 +3,8 @@ package org.onlab.onos.net.flow.instructions;
 import static com.google.common.base.MoreObjects.toStringHelper;
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import java.util.Objects;
+
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.flow.instructions.L2ModificationInstruction.L2SubType;
 import org.onlab.onos.net.flow.instructions.L2ModificationInstruction.ModEtherInstruction;
@@ -117,6 +119,24 @@ public final class Instructions {
             return toStringHelper(type()).toString();
 
         }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(type());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof DropInstruction) {
+                DropInstruction that = (DropInstruction) obj;
+                return Objects.equals(type(), that.type());
+
+            }
+            return false;
+        }
     }
 
 
@@ -140,6 +160,26 @@ public final class Instructions {
             return toStringHelper(type().toString())
                     .add("port", port).toString();
         }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(port, type());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof OutputInstruction) {
+                OutputInstruction that = (OutputInstruction) obj;
+                        Objects.equals(port, that.port);
+
+            }
+            return false;
+        }
     }
 
 }
+
+

@@ -2,6 +2,8 @@ package org.onlab.onos.net.flow.instructions;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
 
+import java.util.Objects;
+
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
@@ -74,6 +76,25 @@ public abstract class L2ModificationInstruction implements Instruction {
                     .add("mac", mac).toString();
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(mac, subtype);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ModEtherInstruction) {
+                ModEtherInstruction that = (ModEtherInstruction) obj;
+                return  Objects.equals(mac, that.mac) &&
+                        Objects.equals(subtype, that.subtype);
+
+            }
+            return false;
+        }
+
 
     }
 
@@ -103,6 +124,25 @@ public abstract class L2ModificationInstruction implements Instruction {
                     .add("id", vlanId).toString();
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(vlanId, subtype());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ModVlanIdInstruction) {
+                ModVlanIdInstruction that = (ModVlanIdInstruction) obj;
+                return  Objects.equals(vlanId, that.vlanId);
+
+            }
+            return false;
+        }
+
+
     }
 
     /**
@@ -131,6 +171,24 @@ public abstract class L2ModificationInstruction implements Instruction {
                     .add("pcp", Long.toHexString(vlanPcp)).toString();
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(vlanPcp, subtype());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ModVlanPcpInstruction) {
+                ModVlanPcpInstruction that = (ModVlanPcpInstruction) obj;
+                return  Objects.equals(vlanPcp, that.vlanPcp);
+
+            }
+            return false;
+        }
+
     }
 
 

@@ -2,6 +2,8 @@ package org.onlab.onos.net.flow.instructions;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
 
+import java.util.Objects;
+
 import org.onlab.packet.IpPrefix;
 
 /**
@@ -66,5 +68,23 @@ public abstract class L3ModificationInstruction implements Instruction {
                     .add("ip", ip).toString();
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(ip, subtype());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ModIPInstruction) {
+                ModIPInstruction that = (ModIPInstruction) obj;
+                return  Objects.equals(ip, that.ip);
+
+            }
+            return false;
+        }
+
     }
 }

@@ -24,7 +24,7 @@ public abstract class AbstractIntent implements Intent {
     }
 
     @Override
-    public IntentId getId() {
+    public IntentId id() {
         return id;
     }
 

@@ -3,6 +3,7 @@ package org.onlab.onos.net.intent;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
@@ -12,10 +13,10 @@ import java.util.List;
  *
  * @param <T> the enum of operators <br>
  *            This enum must be defined in each sub-classes.
- *
  */
 public abstract class BatchOperation<T extends BatchOperationEntry<?, ?>> {
-    private List<T> ops;
+
+    private final List<T> ops;
 
     /**
      * Creates new {@link BatchOperation} object.
@@ -30,7 +31,7 @@ public abstract class BatchOperation<T extends BatchOperationEntry<?, ?>> {
      *
      * @param batchOperations the list of batch operation entries.
      */
-    public BatchOperation(List<T> batchOperations) {
+    public BatchOperation(Collection<T> batchOperations) {
         ops = new LinkedList<>(checkNotNull(batchOperations));
     }
 
@@ -61,6 +62,10 @@ public abstract class BatchOperation<T extends BatchOperationEntry<?, ?>> {
 
     /**
      * Adds an operation.
+     * FIXME: Brian promises that the Intent Framework
+     * will not modify the batch operation after it has submitted it.
+     * Ali would prefer immutablity, but trusts brian for better or
+     * for worse.
      *
      * @param entry the operation to be added
      * @return this object if succeeded, null otherwise

@@ -15,14 +15,7 @@ public class BatchOperationEntry<T extends Enum<?>, U extends BatchOperationTarg
     private final T operator;
     private final U target;
 
-    /**
-     * Default constructor for serializer.
-     */
-    @Deprecated
-    protected BatchOperationEntry() {
-        this.operator = null;
-        this.target = null;
-    }
+
 
     /**
      * Constructs new instance for the entry of the BatchOperation.

 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
+import com.google.common.base.Objects;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.Objects;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Abstraction of connectivity intent for traffic matching some criteria.
@@ -26,17 +25,18 @@ public abstract class ConnectivityIntent extends AbstractIntent {
 
     /**
      * Creates a connectivity intent that matches on the specified intent
-     * and applies the specified action.
+     * and applies the specified treatement.
      *
-     * @param id    intent identifier
-     * @param match traffic match
-     * @param action action
-     * @throws NullPointerException if the match or action is null
+     * @param intentId   intent identifier
+     * @param selector   traffic selector
+     * @param treatement treatement
+     * @throws NullPointerException if the selector or treatement is null
      */
-    protected ConnectivityIntent(IntentId id, TrafficSelector match, TrafficTreatment action) {
-        super(id);
-        this.selector = checkNotNull(match);
-        this.treatment = checkNotNull(action);
+    protected ConnectivityIntent(IntentId intentId, TrafficSelector selector,
+                                 TrafficTreatment treatement) {
+        super(intentId);
+        this.selector = checkNotNull(selector);
+        this.treatment = checkNotNull(treatement);
     }
 
     /**
@@ -53,7 +53,7 @@ public abstract class ConnectivityIntent extends AbstractIntent {
      *
      * @return traffic match
      */
-    public TrafficSelector getTrafficSelector() {
+    public TrafficSelector selector() {
         return selector;
     }
 
@@ -62,7 +62,7 @@ public abstract class ConnectivityIntent extends AbstractIntent {
      *
      * @return applied action
      */
-    public TrafficTreatment getTrafficTreatment() {
+    public TrafficTreatment treatment() {
         return treatment;
     }
 

+package org.onlab.onos.net.intent;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Abstraction of end-station to end-station bidirectional connectivity.
+ */
+public class HostToHostIntent extends ConnectivityIntent {
+
+    private final HostId one;
+    private final HostId two;
+
+    /**
+     * Creates a new point-to-point intent with the supplied ingress/egress
+     * ports.
+     *
+     * @param intentId  intent identifier
+     * @param one       first host
+     * @param two       second host
+     * @param selector  action
+     * @param treatment ingress port
+     * @throws NullPointerException if {@code ingressPort} or {@code egressPort}
+     *                              is null.
+     */
+    public HostToHostIntent(IntentId intentId, HostId one, HostId two,
+                            TrafficSelector selector,
+                            TrafficTreatment treatment) {
+        super(intentId, selector, treatment);
+        this.one = checkNotNull(one);
+        this.two = checkNotNull(two);
+    }
+
+    /**
+     * Returns identifier of the first host.
+     *
+     * @return first host identifier
+     */
+    public HostId one() {
+        return one;
+    }
+
+    /**
+     * Returns identifier of the second host.
+     *
+     * @return second host identifier
+     */
+    public HostId two() {
+        return two;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        if (!super.equals(o)) {
+            return false;
+        }
+
+        HostToHostIntent that = (HostToHostIntent) o;
+        return Objects.equals(this.one, that.one)
+                && Objects.equals(this.two, that.two);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), one, two);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("id", id())
+                .add("selector", selector())
+                .add("treatment", treatment())
+                .add("one", one)
+                .add("two", two)
+                .toString();
+    }
+
+}

 package org.onlab.onos.net.intent;
 
+import org.onlab.onos.net.Link;
+
+import java.util.Collection;
+
 /**
  * Abstraction of an intent that can be installed into
  * the underlying system without additional compilation.
  */
 public interface InstallableIntent extends Intent {
+
+    /**
+     * Returns the collection of links that are required for this installable
+     * intent to exist.
+     *
+     * @return collection of links
+     */
+    // FIXME: replace this with 'NetworkResource'
+    Collection<Link> requiredLinks();
+
 }

@@ -2,7 +2,7 @@ package org.onlab.onos.net.intent;
 
 /**
  * Abstraction of an application level intent.
- *
+ * <p/>
  * Make sure that an Intent should be immutable when a new type is defined.
  */
 public interface Intent extends BatchOperationTarget {
@@ -11,5 +11,5 @@ public interface Intent extends BatchOperationTarget {
      *
      * @return intent identifier
      */
-    IntentId getId();
+    IntentId id();
 }

 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Objects;
-
-import com.google.common.base.MoreObjects;
+import org.onlab.onos.event.AbstractEvent;
 
 /**
  * A class to represent an intent related event.
  */
-public class IntentEvent {
-
-    // TODO: determine a suitable parent class; if one does not exist, consider introducing one
-
-    private final long time;
-    private final Intent intent;
-    private final IntentState state;
-    private final IntentState previous;
+public class IntentEvent extends AbstractEvent<IntentEvent.Type, Intent> {
 
+    public enum Type {
         /**
-     * Creates an event describing a state change of an intent.
-     *
-     * @param intent subject intent
-     * @param state new intent state
-     * @param previous previous intent state
-     * @param time time the event created in milliseconds since start of epoch
-     * @throws NullPointerException if the intent or state is null
+         * Signifies that a new intent has been submitted to the system.
          */
-    public IntentEvent(Intent intent, IntentState state, IntentState previous, long time) {
-        this.intent = checkNotNull(intent);
-        this.state = checkNotNull(state);
-        this.previous = previous;
-        this.time = time;
-    }
+        SUBMITTED,
 
         /**
-     * Constructor for serializer.
+         * Signifies that an intent has been successfully installed.
          */
-    protected IntentEvent() {
-        this.intent = null;
-        this.state = null;
-        this.previous = null;
-        this.time = 0;
-    }
+        INSTALLED,
 
         /**
-     * Returns the state of the intent which caused the event.
-     *
-     * @return the state of the intent
+         * Signifies that an intent has failed compilation or installation.
          */
-    public IntentState getState() {
-        return state;
-    }
+        FAILED,
 
         /**
-     * Returns the previous state of the intent which caused the event.
-     *
-     * @return the previous state of the intent
+         * Signifies that an intent has been withdrawn from the system.
          */
-    public IntentState getPreviousState() {
-        return previous;
+        WITHDRAWN
     }
 
     /**
-     * Returns the intent associated with the event.
+     * Creates an event of a given type and for the specified intent and the
+     * current time.
      *
-     * @return the intent
+     * @param type   event type
+     * @param intent subject intent
+     * @param time   time the event created in milliseconds since start of epoch
      */
-    public Intent getIntent() {
-        return intent;
+    public IntentEvent(Type type, Intent intent, long time) {
+        super(type, intent, time);
     }
 
     /**
-     * Returns the time at which the event was created.
+     * Creates an event of a given type and for the specified intent and the
+     * current time.
      *
-     * @return the time in milliseconds since start of epoch
+     * @param type   event type
+     * @param intent subject intent
      */
-    public long getTime() {
-        return time;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) {
-            return true;
-        }
-        if (o == null || getClass() != o.getClass()) {
-            return false;
+    public IntentEvent(Type type, Intent intent) {
+        super(type, intent);
     }
 
-        IntentEvent that = (IntentEvent) o;
-        return Objects.equals(this.intent, that.intent)
-                && Objects.equals(this.state, that.state)
-                && Objects.equals(this.previous, that.previous)
-                && Objects.equals(this.time, that.time);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(intent, state, previous, time);
-    }
-
-    @Override
-    public String toString() {
-        return MoreObjects.toStringHelper(getClass())
-                .add("intent", intent)
-                .add("state", state)
-                .add("previous", previous)
-                .add("time", time)
-                .toString();
-    }
 }

@@ -2,7 +2,7 @@ package org.onlab.onos.net.intent;
 
 /**
  * Intent identifier suitable as an external key.
- *
+ * <p/>
  * This class is immutable.
  */
 public final class IntentId implements BatchOperationTarget {

 package org.onlab.onos.net.intent;
 
+import org.onlab.onos.event.EventListener;
+
 /**
  * Listener for {@link IntentEvent intent events}.
  */
-public interface IntentEventListener {
-    /**
-     * Processes the specified intent event.
-     *
-     * @param event the event to process
-     */
-    void event(IntentEvent event);
+public interface IntentListener extends EventListener<IntentEvent> {
 }

 package org.onlab.onos.net.intent;
 
-import java.util.Set;
 
 /**
  * Service for application submitting or withdrawing their intents.
@@ -8,9 +7,9 @@ import java.util.Set;
 public interface IntentService {
     /**
      * Submits an intent into the system.
-     *
-     * This is an asynchronous request meaning that any compiling
-     * or installation activities may be done at later time.
+     * <p/>
+     * This is an asynchronous request meaning that any compiling or
+     * installation activities may be done at later time.
      *
      * @param intent intent to be submitted
      */
@@ -18,9 +17,9 @@ public interface IntentService {
 
     /**
      * Withdraws an intent from the system.
-     *
-     * This is an asynchronous request meaning that the environment
-     * may be affected at later time.
+     * <p/>
+     * This is an asynchronous request meaning that the environment may be
+     * affected at later time.
      *
      * @param intent intent to be withdrawn
      */
@@ -29,20 +28,27 @@ public interface IntentService {
     /**
      * Submits a batch of submit &amp; withdraw operations. Such a batch is
      * assumed to be processed together.
-     *
-     * This is an asynchronous request meaning that the environment
-     * may be affected at later time.
+     * <p/>
+     * This is an asynchronous request meaning that the environment may be
+     * affected at later time.
      *
      * @param operations batch of intent operations
      */
     void execute(IntentOperations operations);
 
     /**
-     * Returns immutable set of intents currently in the system.
+     * Returns an iterable of intents currently in the system.
      *
      * @return set of intents
      */
-    Set<Intent> getIntents();
+    Iterable<Intent> getIntents();
+
+    /**
+     * Returns the number of intents currently in the system.
+     *
+     * @return number of intents
+     */
+    long getIntentCount();
 
     /**
      * Retrieves the intent specified by its identifier.
@@ -56,7 +62,8 @@ public interface IntentService {
      * Retrieves the state of an intent by its identifier.
      *
      * @param id intent identifier
-     * @return the intent state or null if one with the given identifier is not found
+     * @return the intent state or null if one with the given identifier is not
+     * found
      */
     IntentState getIntentState(IntentId id);
 
@@ -65,12 +72,12 @@ public interface IntentService {
      *
      * @param listener listener to be added
      */
-    void addListener(IntentEventListener listener);
+    void addListener(IntentListener listener);
 
     /**
      * Removes the specified listener for intent events.
      *
      * @param listener listener to be removed
      */
-    void removeListener(IntentEventListener listener);
+    void removeListener(IntentListener listener);
 }

 package org.onlab.onos.net.intent;
 
 /**
- * This class represents the states of an intent.
- *
- * <p>
- * Note: The state is expressed as enum, but there is possibility
- * in the future that we define specific class instead of enum to improve
- * the extensibility of state definition.
- * </p>
+ * Representation of the phases an intent may attain during its lifecycle.
  */
 public enum IntentState {
-    // FIXME: requires discussion on State vs. EventType and a solid state-transition diagram
-    // TODO: consider the impact of conflict detection
-    // TODO: consider the impact that external events affect an installed intent
+
     /**
-     * The beginning state.
-     *
+     * Signifies that the intent has been submitted and will start compiling
+     * shortly. However, this compilation may not necessarily occur on the
+     * local controller instance.
+     * <p/>
      * All intent in the runtime take this state first.
      */
     SUBMITTED,
 
     /**
-     * The intent compilation has been completed.
-     *
-     * An intent translation graph (tree) is completely created.
-     * Leaves of the graph are installable intent type.
+     * Signifies that the intent is being compiled into installable intents.
+     * This is a transitional state after which the intent will enter either
+     * {@link #FAILED} state or {@link #INSTALLING} state.
+     */
+    COMPILING,
+
+    /**
+     * Signifies that the resulting installable intents are being installed
+     * into the network environment. This is a transitional state after which
+     * the intent will enter either {@link #INSTALLED} state or
+     * {@link #RECOMPILING} state.
      */
-    COMPILED,
+    INSTALLING,
 
     /**
-     * The intent has been successfully installed.
+     * The intent has been successfully installed. This is a state where the
+     * intent may remain parked until it is withdrawn by the application or
+     * until the network environment changes in some way to make the original
+     * set of installable intents untenable.
      */
     INSTALLED,
 
     /**
-     * The intent is being withdrawn.
-     *
-     * When {@link IntentService#withdraw(Intent)} is called,
-     * the intent takes this state first.
+     * Signifies that the intent is being recompiled into installable intents
+     * as an attempt to adapt to an anomaly in the network environment.
+     * This is a transitional state after which the intent will enter either
+     * {@link #FAILED} state or {@link #INSTALLING} state.
+     * <p/>
+     * Exit to the {@link #FAILED} state may be caused by failure to compile
+     * or by compiling into the same set of installable intents which have
+     * previously failed to be installed.
+     */
+    RECOMPILING,
+
+    /**
+     * Indicates that the intent is being withdrawn. This is a transitional
+     * state, triggered by invocation of the
+     * {@link IntentService#withdraw(Intent)} but one with only one outcome,
+     * which is the the intent being placed in the {@link #WITHDRAWN} state.
      */
     WITHDRAWING,
 
     /**
-     * The intent has been successfully withdrawn.
+     * Indicates that the intent has been successfully withdrawn.
      */
     WITHDRAWN,
 
     /**
-     * The intent has failed to be compiled, installed, or withdrawn.
-     *
-     * When the intent failed to be withdrawn, it is still, at least partially installed.
+     * Signifies that the intent has failed compiling, installing or
+     * recompiling states.
      */
-    FAILED,
+    FAILED
 }

+package org.onlab.onos.net.intent;
+
+import org.onlab.onos.store.Store;
+
+import java.util.List;
+
+/**
+ * Manages inventory of end-station intents; not intended for direct use.
+ */
+public interface IntentStore extends Store<IntentEvent, IntentStoreDelegate> {
+
+    /**
+     * Submits a new intent into the store. If the returned event is not
+     * null, the manager is expected to dispatch the event and then to kick
+     * off intent compilation process. Otherwise, another node has been elected
+     * to perform the compilation process and the node will learn about
+     * the submittal and results of the intent compilation via the delegate
+     * mechanism.
+     *
+     * @param intent intent to be submitted
+     * @return event indicating the intent was submitted or null if no
+     * change resulted, e.g. duplicate intent
+     */
+    IntentEvent createIntent(Intent intent);
+
+    /**
+     * Removes the specified intent from the inventory.
+     *
+     * @param intentId intent identification
+     * @return removed state transition event or null if intent was not found
+     */
+    IntentEvent removeIntent(IntentId intentId);
+
+    /**
+     * Returns the number of intents in the store.
+     */
+    long getIntentCount();
+
+    /**
+     * Returns a collection of all intents in the store.
+     *
+     * @return iterable collection of all intents
+     */
+    Iterable<Intent> getIntents();
+
+    /**
+     * Returns the intent with the specified identifer.
+     *
+     * @param intentId intent identification
+     * @return intent or null if not found
+     */
+    Intent getIntent(IntentId intentId);
+
+    /**
+     * Returns the state of the specified intent.
+     *
+     * @param intentId intent identification
+     * @return current intent state
+     */
+    IntentState getIntentState(IntentId intentId);
+
+    /**
+     * Sets the state of the specified intent to the new state.
+     *
+     * @param intent   intent whose state is to be changed
+     * @param newState new state
+     * @return state transition event
+     */
+    IntentEvent setState(Intent intent, IntentState newState);
+
+    /**
+     * Adds the installable intents which resulted from compilation of the
+     * specified original intent.
+     *
+     * @param intentId           original intent identifier
+     * @param installableIntents compiled installable intents
+     */
+    void addInstallableIntents(IntentId intentId,
+                               List<InstallableIntent> installableIntents);
+
+    /**
+     * Returns the list of the installable events associated with the specified
+     * original intent.
+     *
+     * @param intentId original intent identifier
+     * @return compiled installable intents
+     */
+    List<InstallableIntent> getInstallableIntents(IntentId intentId);
+
+    // TODO: this should be triggered from with the store as a result of removeIntent call
+
+    /**
+     * Removes any installable intents which resulted from compilation of the
+     * specified original intent.
+     *
+     * @param intentId original intent identifier
+     * @return compiled state transition event
+     */
+    void removeInstalledIntents(IntentId intentId);
+
+}

+package org.onlab.onos.net.intent;
+
+import org.onlab.onos.store.StoreDelegate;
+
+/**
+ * Intent store delegate abstraction.
+ */
+public interface IntentStoreDelegate extends StoreDelegate<IntentEvent> {
+}

 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Objects;
-import java.util.Set;
-
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.Sets;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.MoreObjects;
-import com.google.common.collect.Sets;
+import java.util.Objects;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Abstraction of multiple source to single destination connectivity intent.
  */
 public class MultiPointToSinglePointIntent extends ConnectivityIntent {
 
-    private final Set<ConnectPoint> ingressPorts;
-    private final ConnectPoint egressPort;
+    private final Set<ConnectPoint> ingressPoints;
+    private final ConnectPoint egressPoint;
 
     /**
      * Creates a new multi-to-single point connectivity intent for the specified
@@ -28,23 +27,25 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
      * @param id           intent identifier
      * @param match        traffic match
      * @param action       action
-     * @param ingressPorts set of ports from which ingress traffic originates
-     * @param egressPort   port to which traffic will egress
-     * @throws NullPointerException if {@code ingressPorts} or
-     * {@code egressPort} is null.
-     * @throws IllegalArgumentException if the size of {@code ingressPorts} is
+     * @param ingressPoints set of ports from which ingress traffic originates
+     * @param egressPoint   port to which traffic will egress
+     * @throws NullPointerException     if {@code ingressPoints} or
+     *                                  {@code egressPoint} is null.
+     * @throws IllegalArgumentException if the size of {@code ingressPoints} is
      *                                  not more than 1
      */
-    public MultiPointToSinglePointIntent(IntentId id, TrafficSelector match, TrafficTreatment action,
-            Set<ConnectPoint> ingressPorts, ConnectPoint egressPort) {
+    public MultiPointToSinglePointIntent(IntentId id, TrafficSelector match,
+                                         TrafficTreatment action,
+                                         Set<ConnectPoint> ingressPoints,
+                                         ConnectPoint egressPoint) {
         super(id, match, action);
 
-        checkNotNull(ingressPorts);
-        checkArgument(!ingressPorts.isEmpty(),
+        checkNotNull(ingressPoints);
+        checkArgument(!ingressPoints.isEmpty(),
                       "there should be at least one ingress port");
 
-        this.ingressPorts = Sets.newHashSet(ingressPorts);
-        this.egressPort = checkNotNull(egressPort);
+        this.ingressPoints = Sets.newHashSet(ingressPoints);
+        this.egressPoint = checkNotNull(egressPoint);
     }
 
     /**
@@ -52,8 +53,8 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
      */
     protected MultiPointToSinglePointIntent() {
         super();
-        this.ingressPorts = null;
-        this.egressPort = null;
+        this.ingressPoints = null;
+        this.egressPoint = null;
     }
 
     /**
@@ -62,8 +63,8 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
      *
      * @return set of ingress ports
      */
-    public Set<ConnectPoint> getIngressPorts() {
-        return ingressPorts;
+    public Set<ConnectPoint> ingressPoints() {
+        return ingressPoints;
     }
 
     /**
@@ -71,8 +72,8 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
      *
      * @return egress port
      */
-    public ConnectPoint getEgressPort() {
-        return egressPort;
+    public ConnectPoint egressPoint() {
+        return egressPoint;
     }
 
     @Override
@@ -88,23 +89,23 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
         }
 
         MultiPointToSinglePointIntent that = (MultiPointToSinglePointIntent) o;
-        return Objects.equals(this.ingressPorts, that.ingressPorts)
-                && Objects.equals(this.egressPort, that.egressPort);
+        return Objects.equals(this.ingressPoints, that.ingressPoints)
+                && Objects.equals(this.egressPoint, that.egressPoint);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(super.hashCode(), ingressPorts, egressPort);
+        return Objects.hash(super.hashCode(), ingressPoints, egressPoint);
     }
 
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("match", getTrafficSelector())
-                .add("action", getTrafficTreatment())
-                .add("ingressPorts", getIngressPorts())
-                .add("egressPort", getEgressPort())
+                .add("id", id())
+                .add("match", selector())
+                .add("action", treatment())
+                .add("ingressPoints", ingressPoints())
+                .add("egressPoint", egressPoint())
                 .toString();
     }
 }

@@ -3,30 +3,30 @@ package org.onlab.onos.net.intent;
 import org.onlab.onos.net.ConnectPoint;
 
 // TODO: consider if this intent should be sub-class of ConnectivityIntent
+
 /**
  * An optical layer Intent for a connectivity from a transponder port to another
  * transponder port.
- * <p>
+ * <p/>
  * This class doesn't accepts lambda specifier. This class computes path between
  * ports and assign lambda automatically. The lambda can be specified using
  * OpticalPathFlow class.
  */
 public class OpticalConnectivityIntent extends AbstractIntent {
-    protected ConnectPoint srcConnectPoint;
-    protected ConnectPoint dstConnectPoint;
+    protected ConnectPoint src;
+    protected ConnectPoint dst;
 
     /**
      * Constructor.
      *
      * @param id  ID for this new Intent object.
-     * @param srcConnectPoint The source transponder port.
-     * @param dstConnectPoint The destination transponder port.
+     * @param src The source transponder port.
+     * @param dst The destination transponder port.
      */
-    public OpticalConnectivityIntent(IntentId id,
-            ConnectPoint srcConnectPoint, ConnectPoint dstConnectPoint) {
+    public OpticalConnectivityIntent(IntentId id, ConnectPoint src, ConnectPoint dst) {
         super(id);
-        this.srcConnectPoint = srcConnectPoint;
-        this.dstConnectPoint = dstConnectPoint;
+        this.src = src;
+        this.dst = dst;
     }
 
     /**
@@ -34,8 +34,8 @@ public class OpticalConnectivityIntent extends AbstractIntent {
      */
     protected OpticalConnectivityIntent() {
         super();
-        this.srcConnectPoint = null;
-        this.dstConnectPoint = null;
+        this.src = null;
+        this.dst = null;
     }
 
     /**
@@ -44,7 +44,7 @@ public class OpticalConnectivityIntent extends AbstractIntent {
      * @return The source transponder port.
      */
     public ConnectPoint getSrcConnectPoint() {
-        return srcConnectPoint;
+        return src;
     }
 
     /**
@@ -52,7 +52,7 @@ public class OpticalConnectivityIntent extends AbstractIntent {
      *
      * @return The source transponder port.
      */
-    public ConnectPoint getDstConnectPoint() {
-        return dstConnectPoint;
+    public ConnectPoint getDst() {
+        return dst;
     }
 }

 package org.onlab.onos.net.intent;
 
-import java.util.Objects;
-
+import com.google.common.base.MoreObjects;
 import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.Link;
 import org.onlab.onos.net.Path;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.MoreObjects;
+import java.util.Collection;
+import java.util.Objects;
 
 /**
  * Abstraction of explicitly path specified connectivity intent.
  */
-public class PathIntent extends PointToPointIntent {
+public class PathIntent extends PointToPointIntent implements InstallableIntent {
 
     private final Path path;
 
@@ -45,7 +46,7 @@ public class PathIntent extends PointToPointIntent {
      *
      * @return traversed links
      */
-    public Path getPath() {
+    public Path path() {
         return path;
     }
 
@@ -78,12 +79,18 @@ public class PathIntent extends PointToPointIntent {
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("match", getTrafficSelector())
-                .add("action", getTrafficTreatment())
-                .add("ingressPort", getIngressPort())
-                .add("egressPort", getEgressPort())
+                .add("id", id())
+                .add("match", selector())
+                .add("action", treatment())
+                .add("ingressPort", ingressPoint())
+                .add("egressPort", egressPoint())
                 .add("path", path)
                 .toString();
     }
+
+    @Override
+    public Collection<Link> requiredLinks() {
+        return path.links();
+    }
+
 }

 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Objects;
-
+import com.google.common.base.MoreObjects;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.MoreObjects;
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Abstraction of point-to-point connectivity.
  */
 public class PointToPointIntent extends ConnectivityIntent {
 
-    private final ConnectPoint ingressPort;
-    private final ConnectPoint egressPort;
+    private final ConnectPoint ingressPoint;
+    private final ConnectPoint egressPoint;
 
     /**
      * Creates a new point-to-point intent with the supplied ingress/egress
      * ports.
      *
      * @param id           intent identifier
-     * @param match       traffic match
-     * @param action      action
-     * @param ingressPort ingress port
-     * @param egressPort  egress port
-     * @throws NullPointerException if {@code ingressPort} or {@code egressPort} is null.
+     * @param selector     traffic selector
+     * @param treatment    treatment
+     * @param ingressPoint ingress port
+     * @param egressPoint  egress port
+     * @throws NullPointerException if {@code ingressPoint} or {@code egressPoints} is null.
      */
-    public PointToPointIntent(IntentId id, TrafficSelector match, TrafficTreatment action,
-                              ConnectPoint ingressPort, ConnectPoint egressPort) {
-        super(id, match, action);
-        this.ingressPort = checkNotNull(ingressPort);
-        this.egressPort = checkNotNull(egressPort);
+    public PointToPointIntent(IntentId id, TrafficSelector selector,
+                              TrafficTreatment treatment,
+                              ConnectPoint ingressPoint,
+                              ConnectPoint egressPoint) {
+        super(id, selector, treatment);
+        this.ingressPoint = checkNotNull(ingressPoint);
+        this.egressPoint = checkNotNull(egressPoint);
     }
 
     /**
@@ -41,8 +42,8 @@ public class PointToPointIntent extends ConnectivityIntent {
      */
     protected PointToPointIntent() {
         super();
-        this.ingressPort = null;
-        this.egressPort = null;
+        this.ingressPoint = null;
+        this.egressPoint = null;
     }
 
     /**
@@ -51,8 +52,8 @@ public class PointToPointIntent extends ConnectivityIntent {
      *
      * @return ingress port
      */
-    public ConnectPoint getIngressPort() {
-        return ingressPort;
+    public ConnectPoint ingressPoint() {
+        return ingressPoint;
     }
 
     /**
@@ -60,8 +61,8 @@ public class PointToPointIntent extends ConnectivityIntent {
      *
      * @return egress port
      */
-    public ConnectPoint getEgressPort() {
-        return egressPort;
+    public ConnectPoint egressPoint() {
+        return egressPoint;
     }
 
     @Override
@@ -77,23 +78,23 @@ public class PointToPointIntent extends ConnectivityIntent {
         }
 
         PointToPointIntent that = (PointToPointIntent) o;
-        return Objects.equals(this.ingressPort, that.ingressPort)
-                && Objects.equals(this.egressPort, that.egressPort);
+        return Objects.equals(this.ingressPoint, that.ingressPoint)
+                && Objects.equals(this.egressPoint, that.egressPoint);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(super.hashCode(), ingressPort, egressPort);
+        return Objects.hash(super.hashCode(), ingressPoint, egressPoint);
     }
 
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("match", getTrafficSelector())
-                .add("action", getTrafficTreatment())
-                .add("ingressPort", ingressPort)
-                .add("egressPort", egressPort)
+                .add("id", id())
+                .add("match", selector())
+                .add("action", treatment())
+                .add("ingressPoint", ingressPoint)
+                .add("egressPoints", egressPoint)
                 .toString();
     }
 

 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Objects;
-import java.util.Set;
-
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.Sets;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.MoreObjects;
-import com.google.common.collect.Sets;
+import java.util.Objects;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Abstraction of single source, multiple destination connectivity intent.
  */
 public class SinglePointToMultiPointIntent extends ConnectivityIntent {
 
-    private final ConnectPoint ingressPort;
-    private final Set<ConnectPoint> egressPorts;
+    private final ConnectPoint ingressPoint;
+    private final Set<ConnectPoint> egressPoints;
 
     /**
      * Creates a new single-to-multi point connectivity intent.
      *
      * @param id           intent identifier
-     * @param match       traffic match
-     * @param action      action
-     * @param ingressPort port on which traffic will ingress
-     * @param egressPorts set of ports on which traffic will egress
-     * @throws NullPointerException if {@code ingressPort} or
-     * {@code egressPorts} is null
-     * @throws IllegalArgumentException if the size of {@code egressPorts} is
+     * @param selector     traffic selector
+     * @param treatment    treatment
+     * @param ingressPoint port on which traffic will ingress
+     * @param egressPoints set of ports on which traffic will egress
+     * @throws NullPointerException     if {@code ingressPoint} or
+     *                                  {@code egressPoints} is null
+     * @throws IllegalArgumentException if the size of {@code egressPoints} is
      *                                  not more than 1
      */
-    public SinglePointToMultiPointIntent(IntentId id, TrafficSelector match, TrafficTreatment action,
-                                         ConnectPoint ingressPort,
-                                         Set<ConnectPoint> egressPorts) {
-        super(id, match, action);
-
-        checkNotNull(egressPorts);
-        checkArgument(!egressPorts.isEmpty(),
+    public SinglePointToMultiPointIntent(IntentId id, TrafficSelector selector,
+                                         TrafficTreatment treatment,
+                                         ConnectPoint ingressPoint,
+                                         Set<ConnectPoint> egressPoints) {
+        super(id, selector, treatment);
+
+        checkNotNull(egressPoints);
+        checkArgument(!egressPoints.isEmpty(),
                       "there should be at least one egress port");
 
-        this.ingressPort = checkNotNull(ingressPort);
-        this.egressPorts = Sets.newHashSet(egressPorts);
+        this.ingressPoint = checkNotNull(ingressPoint);
+        this.egressPoints = Sets.newHashSet(egressPoints);
     }
 
     /**
@@ -52,8 +52,8 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
      */
     protected SinglePointToMultiPointIntent() {
         super();
-        this.ingressPort = null;
-        this.egressPorts = null;
+        this.ingressPoint = null;
+        this.egressPoints = null;
     }
 
     /**
@@ -61,8 +61,8 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
      *
      * @return ingress port
      */
-    public ConnectPoint getIngressPort() {
-        return ingressPort;
+    public ConnectPoint ingressPoint() {
+        return ingressPoint;
     }
 
     /**
@@ -70,8 +70,8 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
      *
      * @return set of egress ports
      */
-    public Set<ConnectPoint> getEgressPorts() {
-        return egressPorts;
+    public Set<ConnectPoint> egressPoints() {
+        return egressPoints;
     }
 
     @Override
@@ -87,23 +87,23 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
         }
 
         SinglePointToMultiPointIntent that = (SinglePointToMultiPointIntent) o;
-        return Objects.equals(this.ingressPort, that.ingressPort)
-                && Objects.equals(this.egressPorts, that.egressPorts);
+        return Objects.equals(this.ingressPoint, that.ingressPoint)
+                && Objects.equals(this.egressPoints, that.egressPoints);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(super.hashCode(), ingressPort, egressPorts);
+        return Objects.hash(super.hashCode(), ingressPoint, egressPoints);
     }
 
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("match", getTrafficSelector())
-                .add("action", getTrafficTreatment())
-                .add("ingressPort", ingressPort)
-                .add("egressPort", egressPorts)
+                .add("id", id())
+                .add("match", selector())
+                .add("action", treatment())
+                .add("ingressPoint", ingressPoint)
+                .add("egressPort", egressPoints)
                 .toString();
     }
 

 /**
- * Intent Package. TODO
+ * Set of abstractions for conveying high-level intents for treatment of
+ * selected network traffic by allowing applications to express the
+ * <em>what</em> rather than the <em>how</em>. This makes such instructions
+ * largely independent of topology and device specifics, thus allowing them to
+ * survive topology mutations.
+ * <p/>
+ * The controller core provides a suite of built-in intents and their compilers
+ * and installers. However, the intent framework is extensible in that it allows
+ * additional intents and their compilers or installers to be added
+ * dynamically at run-time. This allows others to enhance the initial arsenal of
+ * connectivity and policy-based intents available in base controller software.
+ * <p/>
+ * The following diagram depicts the state transition diagram for each top-level intent:<br>
+ * <img src="doc-files/intent-states.png" alt="ONOS intent states">
+ * <p/>
+ * The controller core accepts the intent specifications and translates them, via a
+ * process referred to as intent compilation, to installable intents, which are
+ * essentially actionable operations on the network environment.
+ * These actions are carried out by intent installation process, which results
+ * in some changes to the environment, e.g. tunnel links being provisioned,
+ * flow rules being installed on the data-plane, optical lambdas being reserved.
+ * <p/>
+ * After an intent is submitted by an application, it will be sent immediately
+ * (but asynchronously) into a compiling phase, then to installing phase and if
+ * all goes according to plan into installed state. Once an application decides
+ * it no longer wishes the intent to hold, it can withdraw it. This describes
+ * the nominal flow. However, it may happen that some issue is encountered.
+ * For example, an application may ask for an objective that is not currently
+ * achievable, e.g. connectivity across to unconnected network segments.
+ * If this is the case, the compiling phase may fail to produce a set of
+ * installable intents and instead result in a failed compile. If this occurs,
+ * only a change in the environment can trigger a transition back to the
+ * compiling state.
+ * <p/>
+ * Similarly, an issue may be encountered during the installation phase in
+ * which case the framework will attempt to recompile the intent to see if an
+ * alternate approach is available. If so, the intent will be sent back to
+ * installing phase. Otherwise, it will be parked in the failed state. Another
+ * scenario that’s very likely to be encountered is where the intent is
+ * successfully compiled and installed, but due to some topology event, such
+ * as a downed or downgraded link, loss of throughput may occur or connectivity
+ * may be lost altogether, thus impacting the viability of a previously
+ * satisfied intent. If this occurs, the framework will attempt to recompile
+ * the intent, and if an alternate approach is available, its installation
+ * will be attempted. Otherwise, the original top-level intent will be parked
+ * in the failed state.
+ * <p/>
+ * Please note that all *ing states, depicted in orange, are transitional and
+ * are expected to last only a brief amount of time. The rest of the states
+ * are parking states where the intent may spent some time; except for the
+ * submitted state of course. There, the intent may pause, but only briefly,
+ * while the system determines where to perform the compilation or while it
+ * performs global recomputation/optimization across all prior intents.
  */
-
 package org.onlab.onos.net.intent;
\ No newline at end of file

 package org.onlab.onos.net.link;
 
 import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.Description;
 import org.onlab.onos.net.Link;
 
 /**
  * Describes an infrastructure link.
  */
-public interface LinkDescription {
+public interface LinkDescription extends Description {
 
     /**
      * Returns the link source.

@@ -24,7 +24,7 @@ public abstract class DefaultPacketContext implements PacketContext {
         this.inPkt = inPkt;
         this.outPkt = outPkt;
         this.block = new AtomicBoolean(block);
-        this.builder = new DefaultTrafficTreatment.Builder();
+        this.builder = DefaultTrafficTreatment.builder();
     }
 
     @Override

@@ -3,6 +3,7 @@ package org.onlab.onos.net.provider;
 import java.util.Objects;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * External identity of a {@link org.onlab.onos.net.provider.Provider} family.
@@ -19,10 +20,22 @@ import static com.google.common.base.MoreObjects.toStringHelper;
  */
 public class ProviderId {
 
+    /**
+     * Represents no provider ID.
+     */
+    public static final ProviderId NONE = new ProviderId();
+
     private final String scheme;
     private final String id;
     private final boolean ancillary;
 
+    // For serialization
+    private ProviderId() {
+        scheme = null;
+        id = null;
+        ancillary = false;
+    }
+
     /**
      * Creates a new primary provider identifier from the specified string.
      * The providers are expected to follow the reverse DNS convention, e.g.
@@ -45,8 +58,8 @@ public class ProviderId {
      * @param ancillary ancillary provider indicator
      */
     public ProviderId(String scheme, String id, boolean ancillary) {
-        this.scheme = scheme;
-        this.id = id;
+        this.scheme = checkNotNull(scheme, "Scheme cannot be null");
+        this.id = checkNotNull(id, "ID cannot be null");
         this.ancillary = ancillary;
     }
 

 package org.onlab.onos.net.proxyarp;
 
+import org.onlab.onos.net.packet.PacketContext;
 import org.onlab.packet.Ethernet;
 import org.onlab.packet.IpPrefix;
 
@@ -33,4 +34,12 @@ public interface ProxyArpService {
      */
     void forward(Ethernet eth);
 
+    /**
+     * Handles a arp packet.
+     * Replies to arp requests and forwards request to the  right place.
+     * @param context the packet context to handle
+     * @return true if handled, false otherwise.
+     */
+    boolean handleArp(PacketContext context);
+
 }

 package org.onlab.onos.net.topology;
 
 import org.onlab.onos.event.AbstractEvent;
+import org.onlab.onos.event.Event;
+
+import java.util.List;
 
 /**
  * Describes network topology event.
  */
 public class TopologyEvent extends AbstractEvent<TopologyEvent.Type, Topology> {
 
+    private final List<Event> reasons;
+
     /**
      * Type of topology events.
      */
@@ -23,9 +28,11 @@ public class TopologyEvent extends AbstractEvent<TopologyEvent.Type, Topology> {
      *
      * @param type     topology event type
      * @param topology event topology subject
+     * @param reasons  list of events that triggered topology change
      */
-    public TopologyEvent(Type type, Topology topology) {
+    public TopologyEvent(Type type, Topology topology, List<Event> reasons) {
         super(type, topology);
+        this.reasons = reasons;
     }
 
     /**
@@ -33,10 +40,24 @@ public class TopologyEvent extends AbstractEvent<TopologyEvent.Type, Topology> {
      *
      * @param type     link event type
      * @param topology event topology subject
+     * @param reasons  list of events that triggered topology change
      * @param time     occurrence time
      */
-    public TopologyEvent(Type type, Topology topology, long time) {
+    public TopologyEvent(Type type, Topology topology, List<Event> reasons,
+                         long time) {
         super(type, topology, time);
+        this.reasons = reasons;
+    }
+
+
+    /**
+     * Returns the list of events that triggered the topology change.
+     *
+     * @return list of events responsible for change in topology; null if
+     * initial topology computation
+     */
+    public List<Event> reasons() {
+        return reasons;
     }
 
 }

+package org.onlab.onos.store;
+
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+
+//TODO: Consider renaming to DeviceClockProviderService?
+/**
+* Interface for feeding term information to a logical clock service
+* that vends per device timestamps.
+*/
+public interface ClockProviderService {
+
+    /**
+     * Updates the mastership term for the specified deviceId.
+     *
+     * @param deviceId device identifier.
+     * @param term mastership term.
+     */
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term);
+}

 package org.onlab.onos.store;
 
-import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.net.DeviceId;
 
 // TODO: Consider renaming to DeviceClockService?
@@ -15,12 +14,4 @@ public interface ClockService {
      * @return timestamp.
      */
     public Timestamp getTimestamp(DeviceId deviceId);
-
-    // TODO: Should this be here or separate as Admin service, etc.?
-    /**
-     * Updates the mastership term for the specified deviceId.
-     * @param deviceId device identifier.
-     * @param term mastership term.
-     */
-    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term);
 }

@@ -2,7 +2,15 @@ package org.onlab.onos.store;
 
 /**
  * Opaque version structure.
+ * <p>
+ * Classes implementing this interface must also implement
+ * {@link #hashCode()} and {@link #equals(Object)}.
  */
 public interface Timestamp extends Comparable<Timestamp> {
 
+    @Override
+    public abstract int hashCode();
+
+    @Override
+    public abstract boolean equals(Object obj);
 }

+package org.onlab.onos;
+
+import com.google.common.testing.EqualsTester;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+import static org.onlab.onos.Version.version;
+
+/**
+ * Tests of the version descriptor.
+ */
+public class VersionTest {
+
+    @Test
+    public void fromParts() {
+        Version v = version(1, 2, 3, "4321");
+        assertEquals("wrong major", 1, v.major());
+        assertEquals("wrong minor", 2, v.minor());
+        assertEquals("wrong patch", 3, v.patch());
+        assertEquals("wrong build", "4321", v.build());
+    }
+
+    @Test
+    public void fromString() {
+        Version v = version("1.2.3.4321");
+        assertEquals("wrong major", 1, v.major());
+        assertEquals("wrong minor", 2, v.minor());
+        assertEquals("wrong patch", 3, v.patch());
+        assertEquals("wrong build", "4321", v.build());
+    }
+
+    @Test
+    public void snapshot() {
+        Version v = version("1.2.3-SNAPSHOT");
+        assertEquals("wrong major", 1, v.major());
+        assertEquals("wrong minor", 2, v.minor());
+        assertEquals("wrong patch", 3, v.patch());
+        assertEquals("wrong build", "SNAPSHOT", v.build());
+    }
+
+    @Test
+    public void testEquals() {
+        new EqualsTester()
+                .addEqualityGroup(version("1.2.3.4321"), version(1, 2, 3, "4321"))
+                .addEqualityGroup(version("1.9.3.4321"), version(1, 9, 3, "4321"))
+                .addEqualityGroup(version("1.2.8.4321"), version(1, 2, 8, "4321"))
+                .addEqualityGroup(version("1.2.3.x"), version(1, 2, 3, "x"))
+                .testEquals();
+    }
+}
\ No newline at end of file

@@ -36,6 +36,23 @@ public class DefaultAnnotationsTest {
     }
 
     @Test
+    public void union() {
+        annotations = builder().set("foo", "1").set("bar", "2").remove("buz").build();
+        assertEquals("incorrect keys", of("foo", "bar", "buz"), annotations.keys());
+
+        SparseAnnotations updates = builder().remove("foo").set("bar", "3").set("goo", "4").remove("fuzz").build();
+
+        SparseAnnotations result = DefaultAnnotations.union(annotations, updates);
+
+        assertTrue("remove instruction in original remains", result.isRemoved("buz"));
+        assertTrue("remove instruction in update remains", result.isRemoved("fuzz"));
+        assertEquals("incorrect keys", of("buz", "goo", "bar", "fuzz"), result.keys());
+        assertNull("incorrect value", result.value("foo"));
+        assertEquals("incorrect value", "3", result.value("bar"));
+        assertEquals("incorrect value", "4", result.value("goo"));
+    }
+
+    @Test
     public void merge() {
         annotations = builder().set("foo", "1").set("bar", "2").build();
         assertEquals("incorrect keys", of("foo", "bar"), annotations.keys());

@@ -58,7 +58,5 @@ public class DefaultDeviceTest {
         assertEquals("incorrect hw", HW, device.hwVersion());
         assertEquals("incorrect sw", SW, device.swVersion());
         assertEquals("incorrect serial", SN1, device.serialNumber());
-        assertEquals("incorrect serial", SN1, device.serialNumber());
     }
-
 }

@@ -5,6 +5,7 @@ import org.junit.Test;
 import org.onlab.onos.net.provider.ProviderId;
 
 import static org.junit.Assert.assertEquals;
+import static org.onlab.onos.net.DefaultEdgeLink.createEdgeLink;
 import static org.onlab.onos.net.DefaultLinkTest.cp;
 import static org.onlab.onos.net.DeviceId.deviceId;
 import static org.onlab.onos.net.HostId.hostId;
@@ -55,4 +56,24 @@ public class DefaultEdgeLinkTest {
         assertEquals("incorrect time", 123L, link.hostLocation().time());
     }
 
+    @Test
+    public void phantomIngress() {
+        HostLocation hostLocation = new HostLocation(DID1, P1, 123L);
+        EdgeLink link = createEdgeLink(hostLocation, true);
+        assertEquals("incorrect dst", hostLocation, link.dst());
+        assertEquals("incorrect type", Link.Type.EDGE, link.type());
+        assertEquals("incorrect connect point", hostLocation, link.hostLocation());
+        assertEquals("incorrect time", 123L, link.hostLocation().time());
+    }
+
+    @Test
+    public void phantomEgress() {
+        ConnectPoint hostLocation = new ConnectPoint(DID1, P1);
+        EdgeLink link = createEdgeLink(hostLocation, false);
+        assertEquals("incorrect src", hostLocation, link.src());
+        assertEquals("incorrect type", Link.Type.EDGE, link.type());
+        assertEquals("incorrect connect point", hostLocation, link.hostLocation());
+        assertEquals("incorrect time", 0L, link.hostLocation().time());
+    }
+
 }

@@ -39,7 +39,7 @@ public class DeviceEventTest extends AbstractEventTest {
         Device device = createDevice();
         Port port = new DefaultPort(device, PortNumber.portNumber(123), true);
         long before = System.currentTimeMillis();
-        DeviceEvent event = new DeviceEvent(DeviceEvent.Type.DEVICE_ADDED, device);
+        DeviceEvent event = new DeviceEvent(DeviceEvent.Type.DEVICE_ADDED, device, port);
         long after = System.currentTimeMillis();
         validateEvent(event, DeviceEvent.Type.DEVICE_ADDED, device, before, after);
     }

@@ -16,8 +16,8 @@ import org.onlab.onos.net.flow.TrafficTreatment;
 public abstract class ConnectivityIntentTest extends IntentTest {
 
     public static final IntentId IID = new IntentId(123);
-    public static final TrafficSelector MATCH = (new DefaultTrafficSelector.Builder()).build();
-    public static final TrafficTreatment NOP = (new DefaultTrafficTreatment.Builder()).build();
+    public static final TrafficSelector MATCH = DefaultTrafficSelector.builder().build();
+    public static final TrafficTreatment NOP = DefaultTrafficTreatment.builder().build();
 
     public static final ConnectPoint P1 = new ConnectPoint(DeviceId.deviceId("111"), PortNumber.portNumber(0x1));
     public static final ConnectPoint P2 = new ConnectPoint(DeviceId.deviceId("222"), PortNumber.portNumber(0x2));

@@ -11,19 +11,19 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
 /**
- * Fake implementation of the intent service to assist in developing tests
- * of the interface contract.
+ * Fake implementation of the intent service to assist in developing tests of
+ * the interface contract.
  */
 public class FakeIntentManager implements TestableIntentService {
 
     private final Map<IntentId, Intent> intents = new HashMap<>();
     private final Map<IntentId, IntentState> intentStates = new HashMap<>();
     private final Map<IntentId, List<InstallableIntent>> installables = new HashMap<>();
-    private final Set<IntentEventListener> listeners = new HashSet<>();
+    private final Set<IntentListener> listeners = new HashSet<>();
 
     private final Map<Class<? extends Intent>, IntentCompiler<? extends Intent>> compilers = new HashMap<>();
-    private final Map<Class<? extends InstallableIntent>,
-            IntentInstaller<? extends InstallableIntent>> installers = new HashMap<>();
+    private final Map<Class<? extends InstallableIntent>, IntentInstaller<? extends InstallableIntent>> installers
+        = new HashMap<>();
 
     private final ExecutorService executor = Executors.newSingleThreadExecutor();
     private final List<IntentException> exceptions = new ArrayList<>();
@@ -40,8 +40,7 @@ public class FakeIntentManager implements TestableIntentService {
             @Override
             public void run() {
                 try {
-                    List<InstallableIntent> installable = compileIntent(intent);
-                    installIntents(intent, installable);
+                    executeCompilingPhase(intent);
                 } catch (IntentException e) {
                     exceptions.add(e);
                 }
@@ -55,8 +54,8 @@ public class FakeIntentManager implements TestableIntentService {
             @Override
             public void run() {
                 try {
-                    List<InstallableIntent> installable = getInstallable(intent.getId());
-                    uninstallIntents(intent, installable);
+                    List<InstallableIntent> installable = getInstallable(intent.id());
+                    executeWithdrawingPhase(intent, installable);
                 } catch (IntentException e) {
                     exceptions.add(e);
                 }
@@ -76,61 +75,68 @@ public class FakeIntentManager implements TestableIntentService {
 
     private <T extends InstallableIntent> IntentInstaller<T> getInstaller(T intent) {
         @SuppressWarnings("unchecked")
-        IntentInstaller<T> installer = (IntentInstaller<T>) installers.get(intent.getClass());
+        IntentInstaller<T> installer = (IntentInstaller<T>) installers.get(intent
+                .getClass());
         if (installer == null) {
             throw new IntentException("no installer for class " + intent.getClass());
         }
         return installer;
     }
 
-    private <T extends Intent> List<InstallableIntent> compileIntent(T intent) {
+    private <T extends Intent> void executeCompilingPhase(T intent) {
+        setState(intent, IntentState.COMPILING);
         try {
             // For the fake, we compile using a single level pass
             List<InstallableIntent> installable = new ArrayList<>();
             for (Intent compiled : getCompiler(intent).compile(intent)) {
                 installable.add((InstallableIntent) compiled);
             }
-            setState(intent, IntentState.COMPILED);
-            return installable;
+            executeInstallingPhase(intent, installable);
+
         } catch (IntentException e) {
             setState(intent, IntentState.FAILED);
-            throw e;
+            dispatch(new IntentEvent(IntentEvent.Type.FAILED, intent));
         }
     }
 
-    private void installIntents(Intent intent, List<InstallableIntent> installable) {
+    private void executeInstallingPhase(Intent intent,
+                                        List<InstallableIntent> installable) {
+        setState(intent, IntentState.INSTALLING);
         try {
             for (InstallableIntent ii : installable) {
                 registerSubclassInstallerIfNeeded(ii);
                 getInstaller(ii).install(ii);
             }
             setState(intent, IntentState.INSTALLED);
-            putInstallable(intent.getId(), installable);
+            putInstallable(intent.id(), installable);
+            dispatch(new IntentEvent(IntentEvent.Type.INSTALLED, intent));
+
         } catch (IntentException e) {
             setState(intent, IntentState.FAILED);
-            throw e;
+            dispatch(new IntentEvent(IntentEvent.Type.FAILED, intent));
         }
     }
 
-    private void uninstallIntents(Intent intent, List<InstallableIntent> installable) {
+    private void executeWithdrawingPhase(Intent intent,
+                                         List<InstallableIntent> installable) {
+        setState(intent, IntentState.WITHDRAWING);
         try {
             for (InstallableIntent ii : installable) {
                 getInstaller(ii).uninstall(ii);
             }
+            removeInstallable(intent.id());
             setState(intent, IntentState.WITHDRAWN);
-            removeInstallable(intent.getId());
+            dispatch(new IntentEvent(IntentEvent.Type.WITHDRAWN, intent));
         } catch (IntentException e) {
+            // FIXME: Rework this to always go from WITHDRAWING to WITHDRAWN!
             setState(intent, IntentState.FAILED);
-            throw e;
+            dispatch(new IntentEvent(IntentEvent.Type.FAILED, intent));
         }
     }
 
-
     // Sets the internal state for the given intent and dispatches an event
     private void setState(Intent intent, IntentState state) {
-        IntentState previous = intentStates.get(intent.getId());
-        intentStates.put(intent.getId(), state);
-        dispatch(new IntentEvent(intent, state, previous, System.currentTimeMillis()));
+        intentStates.put(intent.id(), state);
     }
 
     private void putInstallable(IntentId id, List<InstallableIntent> installable) {
@@ -152,15 +158,15 @@ public class FakeIntentManager implements TestableIntentService {
 
     @Override
     public void submit(Intent intent) {
-        intents.put(intent.getId(), intent);
+        intents.put(intent.id(), intent);
         setState(intent, IntentState.SUBMITTED);
+        dispatch(new IntentEvent(IntentEvent.Type.SUBMITTED, intent));
         executeSubmit(intent);
     }
 
     @Override
     public void withdraw(Intent intent) {
-        intents.remove(intent.getId());
-        setState(intent, IntentState.WITHDRAWING);
+        intents.remove(intent.id());
         executeWithdraw(intent);
     }
 
@@ -175,6 +181,11 @@ public class FakeIntentManager implements TestableIntentService {
     }
 
     @Override
+    public long getIntentCount() {
+        return intents.size();
+    }
+
+    @Override
     public Intent getIntent(IntentId id) {
         return intents.get(id);
     }
@@ -185,23 +196,24 @@ public class FakeIntentManager implements TestableIntentService {
     }
 
     @Override
-    public void addListener(IntentEventListener listener) {
+    public void addListener(IntentListener listener) {
         listeners.add(listener);
     }
 
     @Override
-    public void removeListener(IntentEventListener listener) {
+    public void removeListener(IntentListener listener) {
         listeners.remove(listener);
     }
 
     private void dispatch(IntentEvent event) {
-        for (IntentEventListener listener : listeners) {
+        for (IntentListener listener : listeners) {
             listener.event(event);
         }
     }
 
     @Override
-    public <T extends Intent> void registerCompiler(Class<T> cls, IntentCompiler<T> compiler) {
+    public <T extends Intent> void registerCompiler(Class<T> cls,
+            IntentCompiler<T> compiler) {
         compilers.put(cls, compiler);
     }
 
@@ -216,7 +228,8 @@ public class FakeIntentManager implements TestableIntentService {
     }
 
     @Override
-    public <T extends InstallableIntent> void registerInstaller(Class<T> cls, IntentInstaller<T> installer) {
+    public <T extends InstallableIntent> void registerInstaller(Class<T> cls,
+            IntentInstaller<T> installer) {
         installers.put(cls, installer);
     }
 
@@ -252,7 +265,8 @@ public class FakeIntentManager implements TestableIntentService {
         if (!installers.containsKey(intent.getClass())) {
             Class<?> cls = intent.getClass();
             while (cls != Object.class) {
-                // As long as we're within the InstallableIntent class descendants
+                // As long as we're within the InstallableIntent class
+                // descendants
                 if (InstallableIntent.class.isAssignableFrom(cls)) {
                     IntentInstaller<?> installer = installers.get(cls);
                     if (installer != null) {