diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
index a737339..9922587 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
@@ -448,7 +448,6 @@
         if (nextHops.isEmpty()) {
             nextHops.add(destSw);
         }
-
         // If both target switch and dest switch are edge routers, then set IP
         // rule for both subnet and router IP.
         boolean targetIsEdge;
@@ -467,7 +466,7 @@
         if (targetIsEdge && destIsEdge) {
             Set<Ip4Prefix> subnets = config.getSubnets(destSw);
             log.debug("* populateEcmpRoutingRulePartial in device {} towards {} for subnets {}",
-                    targetSw, destSw, subnets);
+                      targetSw, destSw, subnets);
             result = rulePopulator.populateIpRuleForSubnet(targetSw,
                                                            subnets,
                                                            destSw,
@@ -479,24 +478,23 @@
             Ip4Address routerIp = destRouterIp;
             IpPrefix routerIpPrefix = IpPrefix.valueOf(routerIp, IpPrefix.MAX_INET_MASK_LENGTH);
             log.debug("* populateEcmpRoutingRulePartial in device {} towards {} for router IP {}",
-                    targetSw, destSw, routerIpPrefix);
+                      targetSw, destSw, routerIpPrefix);
             result = rulePopulator.populateIpRuleForRouter(targetSw, routerIpPrefix, destSw, nextHops);
             if (!result) {
                 return false;
             }
 
-        // If the target switch is an edge router, then set IP rules for the router IP.
         } else if (targetIsEdge) {
+            // If the target switch is an edge router, then set IP rules for the router IP.
             Ip4Address routerIp = destRouterIp;
             IpPrefix routerIpPrefix = IpPrefix.valueOf(routerIp, IpPrefix.MAX_INET_MASK_LENGTH);
             log.debug("* populateEcmpRoutingRulePartial in device {} towards {} for router IP {}",
-                    targetSw, destSw, routerIpPrefix);
+                      targetSw, destSw, routerIpPrefix);
             result = rulePopulator.populateIpRuleForRouter(targetSw, routerIpPrefix, destSw, nextHops);
             if (!result) {
                 return false;
             }
         }
-
         // Populates MPLS rules to all routers
         log.debug("* populateEcmpRoutingRulePartial in device{} towards {} for all MPLS rules",
                 targetSw, destSw);
@@ -504,7 +502,6 @@
         if (!result) {
             return false;
         }
-
         return true;
     }
 
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
index bc3ce8c..a07a15d 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
@@ -15,6 +15,7 @@
  */
 package org.onosproject.segmentrouting;
 
+import org.onlab.packet.EthType;
 import org.onlab.packet.Ethernet;
 import org.onlab.packet.Ip4Address;
 import org.onlab.packet.Ip4Prefix;
@@ -26,7 +27,6 @@
 import org.onosproject.segmentrouting.config.DeviceConfiguration;
 import org.onosproject.segmentrouting.grouphandler.NeighborSet;
 import org.onosproject.net.DeviceId;
-import org.onosproject.net.Link;
 import org.onosproject.net.Port;
 import org.onosproject.net.PortNumber;
 import org.onosproject.net.flow.DefaultTrafficSelector;
@@ -227,7 +227,15 @@
             treatment = null;
         }
 
-        if (srManager.getNextObjectiveId(deviceId, ns) <= 0) {
+        // setup metadata to pass to nextObjective - indicate the vlan on egress
+        // if needed by the switch pipeline. Since neighbor sets are always to
+        // other neighboring routers, there is no subnet assigned on those ports.
+        TrafficSelector.Builder metabuilder = DefaultTrafficSelector.builder(selector);
+        metabuilder.matchVlanId(
+            VlanId.vlanId(SegmentRoutingManager.ASSIGNED_VLAN_NO_SUBNET));
+
+        int nextId = srManager.getNextObjectiveId(deviceId, ns, metabuilder.build());
+        if (nextId <= 0) {
             log.warn("No next objective in {} for ns: {}", deviceId, ns);
             return false;
         }
@@ -236,7 +244,7 @@
                 .builder()
                 .fromApp(srManager.appId)
                 .makePermanent()
-                .nextStep(srManager.getNextObjectiveId(deviceId, ns))
+                .nextStep(nextId)
                 .withSelector(selector)
                 .withPriority(100)
                 .withFlag(ForwardingObjective.Flag.SPECIFIC);
@@ -279,63 +287,70 @@
         List<ForwardingObjective.Builder> fwdObjBuilders = new ArrayList<>();
 
         // TODO Handle the case of Bos == false
-        sbuilder.matchMplsLabel(MplsLabel.mplsLabel(segmentId));
         sbuilder.matchEthType(Ethernet.MPLS_UNICAST);
+        sbuilder.matchMplsLabel(MplsLabel.mplsLabel(segmentId));
+        TrafficSelector selector = sbuilder.build();
 
-        // If the next hop is the destination router, do PHP
+        // setup metadata to pass to nextObjective - indicate the vlan on egress
+        // if needed by the switch pipeline. Since mpls next-hops are always to
+        // other neighboring routers, there is no subnet assigned on those ports.
+        TrafficSelector.Builder metabuilder = DefaultTrafficSelector.builder(selector);
+        metabuilder.matchVlanId(
+            VlanId.vlanId(SegmentRoutingManager.ASSIGNED_VLAN_NO_SUBNET));
+
+        // If the next hop is the destination router for the segment, do pop
         if (nextHops.size() == 1 && destSwId.equals(nextHops.toArray()[0])) {
             log.debug("populateMplsRule: Installing MPLS forwarding objective for "
-                    + "label {} in switch {} with PHP",
-                    segmentId,
-                    deviceId);
+                    + "label {} in switch {} with pop", segmentId, deviceId);
 
+            // bos pop case (php)
             ForwardingObjective.Builder fwdObjBosBuilder =
                     getMplsForwardingObjective(deviceId,
-                                               destSwId,
                                                nextHops,
                                                true,
-                                               true);
-            // TODO: Check with Sangho on why we need this
-            ForwardingObjective.Builder fwdObjNoBosBuilder =
-                    getMplsForwardingObjective(deviceId,
-                                               destSwId,
-                                               nextHops,
                                                true,
-                                               false);
-            if (fwdObjBosBuilder != null) {
-                fwdObjBuilders.add(fwdObjBosBuilder);
-            } else {
-                log.warn("Failed to set MPLS rules.");
+                                               metabuilder.build());
+            if (fwdObjBosBuilder == null) {
                 return false;
             }
+            fwdObjBuilders.add(fwdObjBosBuilder);
+
+            // XXX not-bos pop case,  SR app multi-label not implemented yet
+            /*ForwardingObjective.Builder fwdObjNoBosBuilder =
+                    getMplsForwardingObjective(deviceId,
+                                               nextHops,
+                                               true,
+                                               false);*/
+
         } else {
+            // next hop is not destination, SR CONTINUE case (swap with self)
             log.debug("Installing MPLS forwarding objective for "
-                    + "label {} in switch {} without PHP",
-                    segmentId,
-                    deviceId);
+                    + "label {} in switch {} without pop", segmentId, deviceId);
 
+            // continue case with bos - this does get triggered in edge routers
+            // and in core routers - driver can handle depending on availability
+            // of MPLS ECMP or not
             ForwardingObjective.Builder fwdObjBosBuilder =
                     getMplsForwardingObjective(deviceId,
-                                               destSwId,
                                                nextHops,
                                                false,
-                                               true);
-            // TODO: Check with Sangho on why we need this
-            ForwardingObjective.Builder fwdObjNoBosBuilder =
-                    getMplsForwardingObjective(deviceId,
-                                               destSwId,
-                                               nextHops,
-                                               false,
-                                               false);
-            if (fwdObjBosBuilder != null) {
-                fwdObjBuilders.add(fwdObjBosBuilder);
-            } else {
-                log.warn("Failed to set MPLS rules.");
+                                               true,
+                                               metabuilder.build());
+            if (fwdObjBosBuilder == null) {
                 return false;
             }
+            fwdObjBuilders.add(fwdObjBosBuilder);
+
+            // XXX continue case with not-bos - SR app multi label not implemented yet
+            // also requires MPLS ECMP
+            /*ForwardingObjective.Builder fwdObjNoBosBuilder =
+                    getMplsForwardingObjective(deviceId,
+                                               nextHops,
+                                               false,
+                                               false); */
+
         }
 
-        TrafficSelector selector = sbuilder.build();
         for (ForwardingObjective.Builder fwdObjBuilder : fwdObjBuilders) {
             ((Builder) ((Builder) fwdObjBuilder.fromApp(srManager.appId)
                     .makePermanent()).withSelector(selector)
@@ -345,76 +360,61 @@
                 forward(deviceId,
                         fwdObjBuilder.
                         add(new SRObjectiveContext(deviceId,
-                                                   SRObjectiveContext.ObjectiveType.FORWARDING)));
+                                    SRObjectiveContext.ObjectiveType.FORWARDING)));
             rulePopulationCounter.incrementAndGet();
         }
 
         return true;
     }
 
-    private ForwardingObjective.Builder getMplsForwardingObjective(DeviceId deviceId,
-                                                                   DeviceId destSw,
-                                                                   Set<DeviceId> nextHops,
-                                                                   boolean phpRequired,
-                                                                   boolean isBos) {
+    private ForwardingObjective.Builder getMplsForwardingObjective(
+                                             DeviceId deviceId,
+                                             Set<DeviceId> nextHops,
+                                             boolean phpRequired,
+                                             boolean isBos,
+                                             TrafficSelector meta) {
+
         ForwardingObjective.Builder fwdBuilder = DefaultForwardingObjective
                 .builder().withFlag(ForwardingObjective.Flag.SPECIFIC);
-        DeviceId nextHop = (DeviceId) nextHops.toArray()[0];
-
-        boolean isEdge;
-        MacAddress srcMac;
-        MacAddress dstMac;
-        try {
-            isEdge = config.isEdgeDevice(deviceId);
-            srcMac = config.getDeviceMac(deviceId);
-            dstMac = config.getDeviceMac(nextHop);
-        } catch (DeviceConfigNotFoundException e) {
-            log.warn(e.getMessage() + " Aborting getMplsForwardingObjective");
-            return null;
-        }
 
         TrafficTreatment.Builder tbuilder = DefaultTrafficTreatment.builder();
 
         if (phpRequired) {
+            // php case - pop should always be flow-action
             log.debug("getMplsForwardingObjective: php required");
             tbuilder.deferred().copyTtlIn();
             if (isBos) {
-                tbuilder.deferred().popMpls(Ethernet.TYPE_IPV4).decNwTtl();
+                tbuilder.deferred().popMpls(EthType.EtherType.IPV4.ethType())
+                    .decNwTtl();
             } else {
-                tbuilder.deferred().popMpls(Ethernet.MPLS_UNICAST).decMplsTtl();
+                tbuilder.deferred().popMpls(EthType.EtherType.MPLS_UNICAST.ethType())
+                    .decMplsTtl();
             }
         } else {
+            // swap with self case - SR CONTINUE
             log.debug("getMplsForwardingObjective: php not required");
             tbuilder.deferred().decMplsTtl();
         }
 
-        if (!isECMPSupportedInTransitRouter() && !isEdge) {
-            PortNumber port = selectOnePort(deviceId, nextHops);
-            if (port == null) {
-                log.warn("No link from {} to {}", deviceId, nextHops);
-                return null;
-            }
-            tbuilder.deferred()
-                    .setEthSrc(srcMac)
-                    .setEthDst(dstMac)
-                    .setOutput(port);
-            fwdBuilder.withTreatment(tbuilder.build());
-        } else {
-            NeighborSet ns = new NeighborSet(nextHops);
-            fwdBuilder.withTreatment(tbuilder.build());
-            fwdBuilder.nextStep(srManager
-                    .getNextObjectiveId(deviceId, ns));
+        // All forwarding is via ECMP group, the metadata informs the driver
+        // that the next-Objective will be used by MPLS flows. In other words,
+        // MPLS ECMP is requested. It is up to the driver to decide if these
+        // packets will be hashed or not.
+        fwdBuilder.withTreatment(tbuilder.build());
+        NeighborSet ns = new NeighborSet(nextHops);
+        log.debug("Trying to get a nextObjid for mpls rule on device:{} to ns:{}",
+                 deviceId, ns);
+
+        int nextId = srManager.getNextObjectiveId(deviceId, ns, meta);
+        if (nextId <= 0) {
+            log.warn("No next objective in {} for ns: {}", deviceId, ns);
+            return null;
         }
 
+        fwdBuilder.nextStep(nextId);
         return fwdBuilder;
     }
 
-    private boolean isECMPSupportedInTransitRouter() {
-
-        // TODO: remove this function when objectives subsystem is supported.
-        return false;
-    }
-
     /**
      * Creates a filtering objective to permit all untagged packets with a
      * dstMac corresponding to the router's MAC address. For those pipelines
@@ -552,22 +552,6 @@
     }
 
 
-    private PortNumber selectOnePort(DeviceId srcId, Set<DeviceId> destIds) {
-
-        Set<Link> links = srManager.linkService.getDeviceLinks(srcId);
-        for (DeviceId destId: destIds) {
-            for (Link link : links) {
-                if (link.dst().deviceId().equals(destId)) {
-                    return link.src().port();
-                } else if (link.src().deviceId().equals(destId)) {
-                    return link.dst().port();
-                }
-            }
-        }
-
-        return null;
-    }
-
     private static class SRObjectiveContext implements ObjectiveContext {
         enum ObjectiveType {
             FILTER,
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
index 84fe516..f6bf649 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
@@ -424,17 +424,22 @@
 
     /**
      * Returns the next objective ID for the given NeighborSet.
-     * If the nextObjectiveID does not exist, a new one is created and returned.
+     * If the nextObjective does not exist, a new one is created and
+     * it's id is returned.
+     * TODO move the side-effect creation of a Next Objective into a new method
      *
      * @param deviceId Device ID
      * @param ns NegighborSet
-     * @return next objective ID
+     * @param meta metadata passed into the creation of a Next Objective
+     * @return next objective ID or -1 if an error was encountered during the
+     *         creation of the nextObjective
      */
-    public int getNextObjectiveId(DeviceId deviceId, NeighborSet ns) {
+    public int getNextObjectiveId(DeviceId deviceId, NeighborSet ns,
+                                  TrafficSelector meta) {
         if (groupHandlerMap.get(deviceId) != null) {
             log.trace("getNextObjectiveId query in device {}", deviceId);
             return groupHandlerMap
-                    .get(deviceId).getNextObjectiveId(ns);
+                    .get(deviceId).getNextObjectiveId(ns, meta);
         } else {
             log.warn("getNextObjectiveId query in device {} not found", deviceId);
             return -1;
@@ -586,7 +591,8 @@
         DefaultGroupHandler groupHandler = groupHandlerMap.get(link.src()
                 .deviceId());
         if (groupHandler != null) {
-            groupHandler.linkUp(link);
+            groupHandler.linkUp(link, mastershipService.isLocalMaster(
+                                           link.src().deviceId()));
         } else {
             Device device = deviceService.getDevice(link.src().deviceId());
             if (device != null) {
@@ -596,7 +602,7 @@
                 processDeviceAdded(device);
                 groupHandler = groupHandlerMap.get(link.src()
                                                    .deviceId());
-                groupHandler.linkUp(link);
+                groupHandler.linkUp(link, mastershipService.isLocalMaster(device.id()));
             }
         }
 
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/TunnelHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/TunnelHandler.java
index 7d025c7..b86adad 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/TunnelHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/TunnelHandler.java
@@ -194,7 +194,7 @@
             tunnel.allowToRemoveGroup(true);
         }
 
-        return groupHandlerMap.get(deviceId).getNextObjectiveId(ns);
+        return groupHandlerMap.get(deviceId).getNextObjectiveId(ns, null);
     }
 
 }
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultEdgeGroupHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultEdgeGroupHandler.java
index 33496bd..6b6d960 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultEdgeGroupHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultEdgeGroupHandler.java
@@ -93,7 +93,7 @@
                 + "with label for sw {} is {}",
                 deviceId, nsSet);
 
-        createGroupsFromNeighborsets(nsSet);
+        //createGroupsFromNeighborsets(nsSet);
     }
 
     @Override
@@ -107,7 +107,7 @@
         Set<NeighborSet> nsSet = computeImpactedNeighborsetForPortEvent(
                                              newNeighborLink.dst().deviceId(),
                                              devicePortMap.keySet());
-        createGroupsFromNeighborsets(nsSet);
+        //createGroupsFromNeighborsets(nsSet);
     }
 
     @Override
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultGroupHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultGroupHandler.java
index b394db5..e792bf6 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultGroupHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultGroupHandler.java
@@ -21,11 +21,11 @@
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
 
 import org.onlab.packet.Ip4Prefix;
@@ -38,6 +38,7 @@
 import org.onosproject.net.Link;
 import org.onosproject.net.PortNumber;
 import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.TrafficSelector;
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.flowobjective.DefaultNextObjective;
 import org.onosproject.net.flowobjective.FlowObjectiveService;
@@ -71,10 +72,10 @@
     protected LinkService linkService;
     protected FlowObjectiveService flowObjectiveService;
 
-    protected HashMap<DeviceId, Set<PortNumber>> devicePortMap = new HashMap<>();
-    protected HashMap<PortNumber, DeviceId> portDeviceMap = new HashMap<>();
-    //protected HashMap<NeighborSet, Integer> deviceNextObjectiveIds =
-    //        new HashMap<NeighborSet, Integer>();
+    protected ConcurrentHashMap<DeviceId, Set<PortNumber>> devicePortMap =
+            new ConcurrentHashMap<>();
+    protected ConcurrentHashMap<PortNumber, DeviceId> portDeviceMap =
+            new ConcurrentHashMap<>();
     protected EventuallyConsistentMap<
         NeighborSetNextObjectiveStoreKey, Integer> nsNextObjStore = null;
     protected EventuallyConsistentMap<
@@ -173,7 +174,7 @@
      *
      * @param newLink new neighbor link
      */
-    public void linkUp(Link newLink) {
+    public void linkUp(Link newLink, boolean isMaster) {
 
         if (newLink.type() != Link.Type.DIRECT) {
             log.warn("linkUp: unknown link type");
@@ -186,6 +187,8 @@
             return;
         }
 
+        log.info("* LinkUP: Device {} linkUp at local port {} to neighbor {}", deviceId,
+                 newLink.src().port(), newLink.dst().deviceId());
         MacAddress dstMac;
         try {
             dstMac = deviceConfig.getDeviceMac(newLink.dst().deviceId());
@@ -194,8 +197,6 @@
             return;
         }
 
-        log.debug("Device {} linkUp at local port {} to neighbor {}", deviceId,
-                  newLink.src().port(), newLink.dst().deviceId());
         addNeighborAtPort(newLink.dst().deviceId(),
                           newLink.src().port());
         /*if (devicePortMap.get(newLink.dst().deviceId()) == null) {
@@ -237,14 +238,20 @@
 
                 nextObjBuilder.addTreatment(tBuilder.build());
 
-                log.debug("linkUp in device {}: Adding Bucket "
-                        + "with Port {} to next object id {}",
+                log.info("**linkUp in device {}: Adding Bucket "
+                        + "with Port {} to next object id {} and amIMaster:{}",
                         deviceId,
                         newLink.src().port(),
-                        nextId);
-                NextObjective nextObjective = nextObjBuilder.
-                        add(new SRNextObjectiveContext(deviceId));
-                flowObjectiveService.next(deviceId, nextObjective);
+                        nextId, isMaster);
+
+                if (isMaster) {
+                    NextObjective nextObjective = nextObjBuilder.
+                            addToExisting(new SRNextObjectiveContext(deviceId));
+                    flowObjectiveService.next(deviceId, nextObjective);
+                }
+            } else {
+                log.warn("linkUp in device {}, but global store has no record "
+                        + "for neighbor-set {}", deviceId, ns);
             }
         }
     }
@@ -305,15 +312,16 @@
 
                 nextObjBuilder.addTreatment(tBuilder.build());
 
-                log.debug("portDown in device {}: Removing Bucket "
+                log.info("**portDown in device {}: Removing Bucket "
                         + "with Port {} to next object id {}",
                         deviceId,
                         port,
                         nextId);
-                NextObjective nextObjective = nextObjBuilder.
+                // should do removefromexisting and only if master
+                /*NextObjective nextObjective = nextObjBuilder.
                         remove(new SRNextObjectiveContext(deviceId));
 
-                flowObjectiveService.next(deviceId, nextObjective);
+                flowObjectiveService.next(deviceId, nextObjective);*/
             }
 
         }
@@ -325,12 +333,15 @@
     /**
      * Returns the next objective associated with the neighborset.
      * If there is no next objective for this neighborset, this API
-     * would create a next objective and return.
+     * would create a next objective and return. Optionally metadata can be
+     * passed in for the creation of the next objective.
      *
      * @param ns neighborset
-     * @return int if found or -1
+     * @param meta metadata passed into the creation of a Next Objective
+     * @return int if found or -1 if there are errors in the creation of the
+     *          neighbor set.
      */
-    public int getNextObjectiveId(NeighborSet ns) {
+    public int getNextObjectiveId(NeighborSet ns, TrafficSelector meta) {
         Integer nextId = nsNextObjStore.
                 get(new NeighborSetNextObjectiveStoreKey(deviceId, ns));
         if (nextId == null) {
@@ -343,7 +354,7 @@
                       .filter((nsStoreEntry) ->
                       (nsStoreEntry.getKey().deviceId().equals(deviceId)))
                       .collect(Collectors.toList()));
-            createGroupsFromNeighborsets(Collections.singleton(ns));
+            createGroupsFromNeighborsets(Collections.singleton(ns), meta);
             nextId = nsNextObjStore.
                     get(new NeighborSetNextObjectiveStoreKey(deviceId, ns));
             if (nextId == null) {
@@ -421,17 +432,19 @@
         // Update DeviceToPort database
         log.debug("Device {} addNeighborAtPort: neighbor {} at port {}",
                   deviceId, neighborId, portToNeighbor);
-        if (devicePortMap.get(neighborId) != null) {
-            devicePortMap.get(neighborId).add(portToNeighbor);
-        } else {
-            Set<PortNumber> ports = new HashSet<>();
-            ports.add(portToNeighbor);
-            devicePortMap.put(neighborId, ports);
+        Set<PortNumber> ports = Collections
+                .newSetFromMap(new ConcurrentHashMap<PortNumber, Boolean>());
+        ports.add(portToNeighbor);
+        Set<PortNumber> portnums = devicePortMap.putIfAbsent(neighborId, ports);
+        if (portnums != null) {
+            portnums.add(portToNeighbor);
         }
 
         // Update portToDevice database
-        if (portDeviceMap.get(portToNeighbor) == null) {
-            portDeviceMap.put(portToNeighbor, neighborId);
+        DeviceId prev = portDeviceMap.putIfAbsent(portToNeighbor, neighborId);
+        if (prev != null) {
+            log.warn("Device: {} port: {} has neighbor: {}. NOT updating "
+                    + "to neighbor: {}", deviceId, portToNeighbor, prev, neighborId);
         }
     }
 
@@ -505,61 +518,66 @@
      * Creates Groups from a set of NeighborSet given.
      *
      * @param nsSet a set of NeighborSet
+     * @param meta metadata passed into the creation of a Next Objective
      */
-    public void createGroupsFromNeighborsets(Set<NeighborSet> nsSet) {
+    public void createGroupsFromNeighborsets(Set<NeighborSet> nsSet,
+                                             TrafficSelector meta) {
         for (NeighborSet ns : nsSet) {
             int nextId = flowObjectiveService.allocateNextId();
             NextObjective.Builder nextObjBuilder = DefaultNextObjective
                     .builder().withId(nextId)
                     .withType(NextObjective.Type.HASHED).fromApp(appId);
-            for (DeviceId d : ns.getDeviceIds()) {
-                if (devicePortMap.get(d) == null) {
-                    log.warn("Device {} is not in the port map yet", d);
+            for (DeviceId neighborId : ns.getDeviceIds()) {
+                if (devicePortMap.get(neighborId) == null) {
+                    log.warn("Neighbor {} is not in the port map yet for dev:{}",
+                             neighborId, deviceId);
                     return;
-                } else if (devicePortMap.get(d).size() == 0) {
+                } else if (devicePortMap.get(neighborId).size() == 0) {
                     log.warn("There are no ports for "
-                            + "the Device {} in the port map yet", d);
+                            + "the Device {} in the port map yet", neighborId);
                     return;
                 }
 
-                MacAddress deviceMac;
+                MacAddress neighborMac;
                 try {
-                    deviceMac = deviceConfig.getDeviceMac(d);
+                    neighborMac = deviceConfig.getDeviceMac(neighborId);
                 } catch (DeviceConfigNotFoundException e) {
                     log.warn(e.getMessage() + " Aborting createGroupsFromNeighborsets.");
                     return;
                 }
 
-                for (PortNumber sp : devicePortMap.get(d)) {
+                for (PortNumber sp : devicePortMap.get(neighborId)) {
                     TrafficTreatment.Builder tBuilder = DefaultTrafficTreatment
                             .builder();
-                    tBuilder.setOutput(sp)
-                            .setEthDst(deviceMac)
+                    tBuilder.setEthDst(neighborMac)
                             .setEthSrc(nodeMacAddr);
                     if (ns.getEdgeLabel() != NeighborSet.NO_EDGE_LABEL) {
                         tBuilder.pushMpls()
                                 .copyTtlOut()
                                 .setMpls(MplsLabel.mplsLabel(ns.getEdgeLabel()));
                     }
+                    tBuilder.setOutput(sp);
                     nextObjBuilder.addTreatment(tBuilder.build());
                 }
             }
-
+            if (meta != null) {
+                nextObjBuilder.setMeta(meta);
+            }
             NextObjective nextObj = nextObjBuilder.
                     add(new SRNextObjectiveContext(deviceId));
-            flowObjectiveService.next(deviceId, nextObj);
-            log.debug("createGroupsFromNeighborsets: Submited "
-                            + "next objective {} in device {}",
+            log.info("**createGroupsFromNeighborsets: Submited "
+                    + "next objective {} in device {}",
                     nextId, deviceId);
+            flowObjectiveService.next(deviceId, nextObj);
             nsNextObjStore.put(new NeighborSetNextObjectiveStoreKey(deviceId, ns),
                                nextId);
         }
     }
 
+
     public void createGroupsFromSubnetConfig() {
         Map<Ip4Prefix, List<PortNumber>> subnetPortMap =
                 this.deviceConfig.getSubnetPortsMap(this.deviceId);
-
         // Construct a broadcast group for each subnet
         subnetPortMap.forEach((subnet, ports) -> {
             SubnetNextObjectiveStoreKey key =
@@ -612,6 +630,9 @@
                     .withType(NextObjective.Type.HASHED).fromApp(appId);
             NextObjective nextObjective = nextObjBuilder.
                     remove(new SRNextObjectiveContext(deviceId));
+            log.info("**removeGroup: Submited "
+                    + "next objective {} in device {}",
+                    objectiveId, deviceId);
             flowObjectiveService.next(deviceId, nextObjective);
 
             for (Map.Entry<NeighborSetNextObjectiveStoreKey, Integer> entry: nsNextObjStore.entrySet()) {
@@ -634,14 +655,14 @@
         }
         @Override
         public void onSuccess(Objective objective) {
-            log.debug("Next objective operation successful in device {}",
-                      deviceId);
+            log.info("Next objective {} operation successful in device {}",
+                      objective.id(), deviceId);
         }
 
         @Override
         public void onError(Objective objective, ObjectiveError error) {
             log.warn("Next objective {} operation failed with error: {} in device {}",
-                     objective, error, deviceId);
+                     objective.id(), error, deviceId);
         }
     }
 }
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultTransitGroupHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultTransitGroupHandler.java
index 8e1b6a8..14d77ba 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultTransitGroupHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/DefaultTransitGroupHandler.java
@@ -81,7 +81,7 @@
         log.debug("createGroupsAtTransitRouter: The neighborset with label "
                 + "for sw {} is {}", deviceId, nsSet);
 
-        createGroupsFromNeighborsets(nsSet);
+        //createGroupsFromNeighborsets(nsSet);
     }
 
     @Override
@@ -95,7 +95,7 @@
         Set<NeighborSet> nsSet = computeImpactedNeighborsetForPortEvent(
                                              newNeighborLink.dst().deviceId(),
                                              devicePortMap.keySet());
-        createGroupsFromNeighborsets(nsSet);
+        //createGroupsFromNeighborsets(nsSet);
     }
 
     @Override
diff --git a/core/api/src/main/java/org/onosproject/net/flowobjective/DefaultForwardingObjective.java b/core/api/src/main/java/org/onosproject/net/flowobjective/DefaultForwardingObjective.java
index 0abf5ab..af48180 100644
--- a/core/api/src/main/java/org/onosproject/net/flowobjective/DefaultForwardingObjective.java
+++ b/core/api/src/main/java/org/onosproject/net/flowobjective/DefaultForwardingObjective.java
@@ -16,6 +16,7 @@
 package org.onosproject.net.flowobjective;
 
 import com.google.common.annotations.Beta;
+
 import org.onosproject.core.ApplicationId;
 import org.onosproject.net.flow.TrafficSelector;
 import org.onosproject.net.flow.TrafficTreatment;
@@ -119,6 +120,53 @@
         return context;
     }
 
+    /*
+     * (non-Javadoc)
+     *
+     * @see java.lang.Object#hashCode()
+     */
+    @Override
+    public int hashCode() {
+        return Objects.hash(selector, flag, permanent,
+                            timeout, appId, priority, nextId,
+                            treatment, op);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see java.lang.Object#equals(java.lang.Object)
+     */
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof DefaultForwardingObjective)) {
+            return false;
+        }
+        final DefaultForwardingObjective other = (DefaultForwardingObjective) obj;
+        boolean nextEq = false, treatmentEq = false;
+        if (this.selector.equals(other.selector) &&
+                this.flag == other.flag &&
+                this.permanent == other.permanent &&
+                this.timeout == other.timeout &&
+                this.appId.equals(other.appId) &&
+                this.priority == other.priority &&
+                this.op == other.op) {
+            if (this.nextId != null && other.nextId != null) {
+                nextEq = this.nextId == other.nextId;
+            }
+            if (this.treatment != null && other.treatment != null) {
+                treatmentEq = this.treatment.equals(other.treatment);
+            }
+            if (nextEq && treatmentEq) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     /**
      * Returns a new builder.
      *
diff --git a/core/api/src/main/java/org/onosproject/net/flowobjective/DefaultNextObjective.java b/core/api/src/main/java/org/onosproject/net/flowobjective/DefaultNextObjective.java
index 20e8929..4701589 100644
--- a/core/api/src/main/java/org/onosproject/net/flowobjective/DefaultNextObjective.java
+++ b/core/api/src/main/java/org/onosproject/net/flowobjective/DefaultNextObjective.java
@@ -18,6 +18,7 @@
 import com.google.common.annotations.Beta;
 import com.google.common.collect.ImmutableList;
 import org.onosproject.core.ApplicationId;
+import org.onosproject.net.flow.TrafficSelector;
 import org.onosproject.net.flow.TrafficTreatment;
 
 import java.util.Collection;
@@ -39,6 +40,7 @@
     private final Integer id;
     private final Operation op;
     private final Optional<ObjectiveContext> context;
+    private final TrafficSelector meta;
 
     private DefaultNextObjective(Builder builder) {
         this.treatments = builder.treatments;
@@ -47,6 +49,7 @@
         this.id = builder.id;
         this.op = builder.op;
         this.context = Optional.ofNullable(builder.context);
+        this.meta = builder.meta;
     }
 
     @Override
@@ -94,6 +97,11 @@
         return context;
     }
 
+    @Override
+    public TrafficSelector meta() {
+        return meta;
+    }
+
     /**
      * Returns a new builder.
      *
@@ -111,6 +119,7 @@
         private List<TrafficTreatment> treatments;
         private Operation op;
         private ObjectiveContext context;
+        private TrafficSelector meta;
 
         private final ImmutableList.Builder<TrafficTreatment> listBuilder
                 = ImmutableList.builder();
@@ -172,6 +181,12 @@
         }
 
         @Override
+        public Builder setMeta(TrafficSelector meta) {
+            this.meta = meta;
+            return this;
+        }
+
+        @Override
         public NextObjective add() {
             treatments = listBuilder.build();
             op = Operation.ADD;
@@ -218,5 +233,55 @@
 
             return new DefaultNextObjective(this);
         }
+
+        @Override
+        public NextObjective addToExisting() {
+            treatments = listBuilder.build();
+            op = Operation.ADD_TO_EXISTING;
+            checkNotNull(appId, "Must supply an application id");
+            checkNotNull(id, "id cannot be null");
+            checkNotNull(type, "The type cannot be null");
+            checkArgument(!treatments.isEmpty(), "Must have at least one treatment");
+
+            return new DefaultNextObjective(this);
+        }
+
+        @Override
+        public NextObjective removeFromExisting() {
+            treatments = listBuilder.build();
+            op = Operation.REMOVE_FROM_EXISTING;
+            checkNotNull(appId, "Must supply an application id");
+            checkNotNull(id, "id cannot be null");
+            checkNotNull(type, "The type cannot be null");
+
+            return new DefaultNextObjective(this);
+        }
+
+        @Override
+        public NextObjective addToExisting(ObjectiveContext context) {
+            treatments = listBuilder.build();
+            op = Operation.ADD_TO_EXISTING;
+            this.context = context;
+            checkNotNull(appId, "Must supply an application id");
+            checkNotNull(id, "id cannot be null");
+            checkNotNull(type, "The type cannot be null");
+            checkArgument(!treatments.isEmpty(), "Must have at least one treatment");
+
+            return new DefaultNextObjective(this);
+        }
+
+        @Override
+        public NextObjective removeFromExisting(ObjectiveContext context) {
+            treatments = listBuilder.build();
+            op = Operation.REMOVE_FROM_EXISTING;
+            this.context = context;
+            checkNotNull(appId, "Must supply an application id");
+            checkNotNull(id, "id cannot be null");
+            checkNotNull(type, "The type cannot be null");
+
+            return new DefaultNextObjective(this);
+        }
+
     }
+
 }
diff --git a/core/api/src/main/java/org/onosproject/net/flowobjective/NextObjective.java b/core/api/src/main/java/org/onosproject/net/flowobjective/NextObjective.java
index 1350d7a..08916eb 100644
--- a/core/api/src/main/java/org/onosproject/net/flowobjective/NextObjective.java
+++ b/core/api/src/main/java/org/onosproject/net/flowobjective/NextObjective.java
@@ -17,6 +17,7 @@
 
 import com.google.common.annotations.Beta;
 import org.onosproject.core.ApplicationId;
+import org.onosproject.net.flow.TrafficSelector;
 import org.onosproject.net.flow.TrafficTreatment;
 
 import java.util.Collection;
@@ -34,7 +35,7 @@
  * - Failover
  * - Simple
  *
- * These types will indicate to the driver what the intended behaviour is.
+ * These types will indicate to the driver what the intended behavior is.
  * For example, a broadcast next objective with a collection of output
  * treatments will indicate to a driver that all output actions are expected
  * to be executed simultaneously. The driver is then free to implement this
@@ -84,6 +85,16 @@
     Type type();
 
     /**
+     * Auxiliary optional information provided to the device-driver.Typically
+     * conveys information about selectors (matches) that are intended to
+     * use this Next Objective.
+     *
+     * @return a selector intended to pass meta information to the device driver.
+     *         Value may be null if no meta information is provided.
+     */
+    TrafficSelector meta();
+
+    /**
      * A next step builder.
      */
     interface Builder extends Objective.Builder {
@@ -131,6 +142,14 @@
         Builder withPriority(int priority);
 
         /**
+         * Set meta information related to this next objective.
+         *
+         * @param selector match conditions
+         * @return an objective builder
+         */
+        Builder setMeta(TrafficSelector selector);
+
+        /**
          * Builds the next objective that will be added.
          *
          * @return a next objective
@@ -162,6 +181,40 @@
          */
         NextObjective remove(ObjectiveContext context);
 
+        /**
+         * Build the next objective that will be added, with {@link Operation}
+         * ADD_TO_EXISTING.
+         *
+         * @return a next objective
+         */
+        NextObjective addToExisting();
+
+        /**
+         * Build the next objective that will be removed, with {@link Operation}
+         * REMOVE_FROM_EXISTING.
+         *
+         * @return a next objective
+         */
+        NextObjective removeFromExisting();
+
+        /**
+         * Builds the next objective that will be added, with {@link Operation}
+         * ADD_TO_EXISTING. The context will be used to notify the calling application.
+         *
+         * @param context an objective context
+         * @return a next objective
+         */
+        NextObjective addToExisting(ObjectiveContext context);
+
+        /**
+         * Builds the next objective that will be removed, with {@link Operation}
+         * REMOVE_FROM_EXISTING. The context will be used to notify the calling application.
+         *
+         * @param context an objective context
+         * @return a next objective
+         */
+        NextObjective removeFromExisting(ObjectiveContext context);
+
     }
 
 }
diff --git a/core/api/src/main/java/org/onosproject/net/flowobjective/Objective.java b/core/api/src/main/java/org/onosproject/net/flowobjective/Objective.java
index 6ac7a7a..b1d73a7 100644
--- a/core/api/src/main/java/org/onosproject/net/flowobjective/Objective.java
+++ b/core/api/src/main/java/org/onosproject/net/flowobjective/Objective.java
@@ -21,7 +21,7 @@
 import java.util.Optional;
 
 /**
- * Base representation of an flow description.
+ * Base representation of a flow-objective description.
  */
 @Beta
 public interface Objective {
@@ -35,14 +35,30 @@
      */
     enum Operation {
         /**
-         * Adds the objective.
+         * Adds the objective. Can be used for any flow objective. For forwarding
+         * and filtering objectives, existing objectives with identical selector
+         * and priority fields (but different treatments or next) will be replaced.
+         * For next objectives, if modification is desired, ADD will not
+         * do anything - use ADD_TO_EXISTING.
          */
         ADD,
 
         /**
-         * Removes the objective.
+         * Removes the objective. Can be used for any flow objective.
          */
-        REMOVE
+        REMOVE,
+
+        /**
+         * Add to an existing Next Objective. Should not be used for any other
+         * objective.
+         */
+        ADD_TO_EXISTING,
+
+        /**
+         * Remove from an existing Next Objective. Should not be used for any
+         * other objective.
+         */
+        REMOVE_FROM_EXISTING
     }
 
     /**
@@ -129,6 +145,7 @@
          * @return an objective builder
          */
         Builder withPriority(int priority);
+
     }
 
 }
diff --git a/core/api/src/main/java/org/onosproject/net/group/DefaultGroupKey.java b/core/api/src/main/java/org/onosproject/net/group/DefaultGroupKey.java
index 7f00ae7..e1eacd1 100644
--- a/core/api/src/main/java/org/onosproject/net/group/DefaultGroupKey.java
+++ b/core/api/src/main/java/org/onosproject/net/group/DefaultGroupKey.java
@@ -25,6 +25,7 @@
 public class DefaultGroupKey implements GroupKey {
 
     private final byte[] key;
+    protected static final char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();
 
     public DefaultGroupKey(byte[] key) {
         this.key = checkNotNull(key);
@@ -52,4 +53,20 @@
         return Arrays.hashCode(this.key);
     }
 
+    /**
+     * Returns a hex string representation of the byte array that is used
+     * as a group key. This solution was adapted from
+     * http://stackoverflow.com/questions/9655181/
+     */
+    @Override
+    public String toString() {
+        char[] hexChars = new char[key.length * 2];
+        for (int j = 0; j < key.length; j++) {
+            int v = key[j] & 0xFF;
+            hexChars[j * 2] = HEX_ARRAY[v >>> 4];
+            hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
+        }
+        return "GroupKey:0x" + new String(hexChars);
+    }
+
 }
\ No newline at end of file
diff --git a/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java b/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
index a76a298..5ecdc7a 100644
--- a/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
+++ b/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
@@ -54,6 +54,7 @@
 import org.slf4j.LoggerFactory;
 
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
 
@@ -226,10 +227,11 @@
         if (fwd.nextId() != null &&
                 flowObjectiveStore.getNextGroup(fwd.nextId()) == null) {
             log.trace("Queuing forwarding objective for nextId {}", fwd.nextId());
-            if (pendingForwards.putIfAbsent(fwd.nextId(),
-                                            Sets.newHashSet(new PendingNext(deviceId, fwd))) != null) {
-                Set<PendingNext> pending = pendingForwards.get(fwd.nextId());
-                pending.add(new PendingNext(deviceId, fwd));
+            // TODO: change to computeIfAbsent
+            Set<PendingNext> pnext = pendingForwards.putIfAbsent(fwd.nextId(),
+                                         Sets.newHashSet(new PendingNext(deviceId, fwd)));
+            if (pnext != null) {
+                pnext.add(new PendingNext(deviceId, fwd));
             }
             return true;
         }
@@ -412,5 +414,26 @@
         public ForwardingObjective forwardingObjective() {
             return fwd;
         }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(deviceId, fwd);
+        }
+
+        @Override
+        public boolean equals(final Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (!(obj instanceof PendingNext)) {
+                return false;
+            }
+            final PendingNext other = (PendingNext) obj;
+            if (this.deviceId.equals(other.deviceId) &&
+                    this.fwd.equals(other.fwd)) {
+                return true;
+            }
+            return false;
+        }
     }
 }
diff --git a/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java b/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
index a999ee7..83319c3 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
@@ -348,9 +348,11 @@
     public void storeGroupDescription(GroupDescription groupDesc) {
         log.debug("In storeGroupDescription");
         // Check if a group is existing with the same key
-        if (getGroup(groupDesc.deviceId(), groupDesc.appCookie()) != null) {
-            log.warn("Group already exists with the same key {}",
-                     groupDesc.appCookie());
+        Group existingGroup = getGroup(groupDesc.deviceId(), groupDesc.appCookie());
+        if (existingGroup != null) {
+            log.warn("Group already exists with the same key {} in dev:{} with id:{}",
+                     groupDesc.appCookie(), groupDesc.deviceId(),
+                     Integer.toHexString(existingGroup.id().id()));
             return;
         }
 
diff --git a/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java b/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
index f80a97a..1b883a3 100644
--- a/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
+++ b/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
@@ -368,6 +368,7 @@
                     L2ModificationInstruction.ModVlanPcpInstruction.class,
                     L2ModificationInstruction.PopVlanInstruction.class,
                     L2ModificationInstruction.ModMplsLabelInstruction.class,
+                    L2ModificationInstruction.ModMplsBosInstruction.class,
                     L2ModificationInstruction.ModMplsTtlInstruction.class,
                     L2ModificationInstruction.ModTunnelIdInstruction.class,
                     L3ModificationInstruction.class,
diff --git a/drivers/src/main/java/org/onosproject/driver/pipeline/CpqdOFDPA2Pipeline.java b/drivers/src/main/java/org/onosproject/driver/pipeline/CpqdOFDPA2Pipeline.java
index 0cb30d2..937c9ac 100644
--- a/drivers/src/main/java/org/onosproject/driver/pipeline/CpqdOFDPA2Pipeline.java
+++ b/drivers/src/main/java/org/onosproject/driver/pipeline/CpqdOFDPA2Pipeline.java
@@ -18,15 +18,19 @@
 import static org.slf4j.LoggerFactory.getLogger;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
+import java.util.Deque;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.onlab.packet.Ethernet;
 import org.onlab.packet.VlanId;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.net.Port;
 import org.onosproject.net.PortNumber;
+import org.onosproject.net.behaviour.NextGroup;
 import org.onosproject.net.flow.DefaultFlowRule;
 import org.onosproject.net.flow.DefaultTrafficSelector;
 import org.onosproject.net.flow.DefaultTrafficTreatment;
@@ -35,8 +39,18 @@
 import org.onosproject.net.flow.FlowRuleOperationsContext;
 import org.onosproject.net.flow.TrafficSelector;
 import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flow.criteria.Criterion;
+import org.onosproject.net.flow.criteria.EthTypeCriterion;
+import org.onosproject.net.flow.criteria.IPCriterion;
+import org.onosproject.net.flow.criteria.MplsBosCriterion;
+import org.onosproject.net.flow.criteria.MplsCriterion;
 import org.onosproject.net.flow.criteria.PortCriterion;
 import org.onosproject.net.flow.criteria.VlanIdCriterion;
+import org.onosproject.net.flow.instructions.Instruction;
+import org.onosproject.net.flowobjective.ForwardingObjective;
+import org.onosproject.net.flowobjective.ObjectiveError;
+import org.onosproject.net.group.Group;
+import org.onosproject.net.group.GroupKey;
 import org.slf4j.Logger;
 
 
@@ -108,6 +122,81 @@
         return rules;
     }
 
+    @Override
+    protected Collection<FlowRule> processSpecific(ForwardingObjective fwd) {
+        TrafficSelector selector = fwd.selector();
+        EthTypeCriterion ethType =
+                (EthTypeCriterion) selector.getCriterion(Criterion.Type.ETH_TYPE);
+        if ((ethType == null) ||
+                (ethType.ethType().toShort() != Ethernet.TYPE_IPV4) &&
+                (ethType.ethType().toShort() != Ethernet.MPLS_UNICAST)) {
+            log.warn("processSpecific: Unsupported "
+                    + "forwarding objective criteraia");
+            fail(fwd, ObjectiveError.UNSUPPORTED);
+            return Collections.emptySet();
+        }
+
+        int forTableId = -1;
+        TrafficSelector.Builder filteredSelector = DefaultTrafficSelector.builder();
+        if (ethType.ethType().toShort() == Ethernet.TYPE_IPV4) {
+            filteredSelector.matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPDst(((IPCriterion)
+                        selector.getCriterion(Criterion.Type.IPV4_DST)).ip());
+            forTableId = UNICAST_ROUTING_TABLE;
+            log.debug("processing IPv4 specific forwarding objective {} hash{} in dev:{}",
+                      fwd.id(), fwd.hashCode(), deviceId);
+        } else {
+            filteredSelector
+                .matchEthType(Ethernet.MPLS_UNICAST)
+                .matchMplsLabel(((MplsCriterion)
+                        selector.getCriterion(Criterion.Type.MPLS_LABEL)).label());
+            MplsBosCriterion bos = (MplsBosCriterion) selector
+                                        .getCriterion(Criterion.Type.MPLS_BOS);
+            if (bos != null) {
+                filteredSelector.matchMplsBos(bos.mplsBos());
+            }
+            forTableId = MPLS_TABLE_1;
+            log.debug("processing MPLS specific forwarding objective {} hash:{} in dev {}",
+                      fwd.id(), fwd.hashCode(), deviceId);
+        }
+
+        TrafficTreatment.Builder tb = DefaultTrafficTreatment.builder();
+        if (fwd.treatment() != null) {
+            for (Instruction i : fwd.treatment().allInstructions()) {
+                tb.add(i);
+            }
+        }
+
+        if (fwd.nextId() != null) {
+            NextGroup next = flowObjectiveStore.getNextGroup(fwd.nextId());
+            List<Deque<GroupKey>> gkeys = appKryo.deserialize(next.data());
+            // we only need the top level group's key to point the flow to it
+            Group group = groupService.getGroup(deviceId, gkeys.get(0).peekFirst());
+            if (group == null) {
+                log.warn("The group left!");
+                fail(fwd, ObjectiveError.GROUPMISSING);
+                return Collections.emptySet();
+            }
+            tb.deferred().group(group.id());
+        }
+        tb.transition(ACL_TABLE);
+        FlowRule.Builder ruleBuilder = DefaultFlowRule.builder()
+                .fromApp(fwd.appId())
+                .withPriority(fwd.priority())
+                .forDevice(deviceId)
+                .withSelector(filteredSelector.build())
+                .withTreatment(tb.build())
+                .forTable(forTableId);
+
+        if (fwd.permanent()) {
+            ruleBuilder.makePermanent();
+        } else {
+            ruleBuilder.makeTemporary(fwd.timeout());
+        }
+
+        return Collections.singletonList(ruleBuilder.build());
+    }
+
 
     @Override
     protected void initializePipeline() {
diff --git a/drivers/src/main/java/org/onosproject/driver/pipeline/OFDPA2Pipeline.java b/drivers/src/main/java/org/onosproject/driver/pipeline/OFDPA2Pipeline.java
index cf3c7e8..863caeb 100644
--- a/drivers/src/main/java/org/onosproject/driver/pipeline/OFDPA2Pipeline.java
+++ b/drivers/src/main/java/org/onosproject/driver/pipeline/OFDPA2Pipeline.java
@@ -19,9 +19,11 @@
 import static org.slf4j.LoggerFactory.getLogger;
 
 import java.nio.ByteBuffer;
+import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Deque;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -65,15 +67,20 @@
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.flow.criteria.Criteria;
 import org.onosproject.net.flow.criteria.Criterion;
+import org.onosproject.net.flow.criteria.Criterion.Type;
 import org.onosproject.net.flow.criteria.EthCriterion;
 import org.onosproject.net.flow.criteria.EthTypeCriterion;
 import org.onosproject.net.flow.criteria.IPCriterion;
+import org.onosproject.net.flow.criteria.MplsBosCriterion;
+import org.onosproject.net.flow.criteria.MplsCriterion;
 import org.onosproject.net.flow.criteria.PortCriterion;
 import org.onosproject.net.flow.criteria.VlanIdCriterion;
 import org.onosproject.net.flow.instructions.Instruction;
 import org.onosproject.net.flow.instructions.Instructions.OutputInstruction;
 import org.onosproject.net.flow.instructions.L2ModificationInstruction;
+import org.onosproject.net.flow.instructions.L2ModificationInstruction.L2SubType;
 import org.onosproject.net.flow.instructions.L2ModificationInstruction.ModEtherInstruction;
+import org.onosproject.net.flow.instructions.L2ModificationInstruction.ModMplsLabelInstruction;
 import org.onosproject.net.flow.instructions.L2ModificationInstruction.ModVlanIdInstruction;
 import org.onosproject.net.flowobjective.FilteringObjective;
 import org.onosproject.net.flowobjective.FlowObjectiveStore;
@@ -128,50 +135,43 @@
     protected static final int LOWEST_PRIORITY = 0x0;
 
     /*
-     * Group keys are normally generated by using the next Objective id. In the
-     * case of a next objective resulting in a group chain, each group derives a
-     * group key from the next objective id in the following way:
-     * The upper 4 bits of the group-key are used to denote the position of the
-     * group in the group chain. For example, in the chain
-     * group0 --> group1 --> group2 --> port
-     * group0's group key would have the upper 4 bits as 0, group1's upper four
-     * bits would be 1, and so on
-     */
-    private static final int GROUP0MASK = 0x0;
-    private static final int GROUP1MASK = 0x10000000;
-
-    /*
      * OFDPA requires group-id's to have a certain form.
      * L2 Interface Groups have <4bits-0><12bits-vlanid><16bits-portid>
      * L3 Unicast Groups have <4bits-2><28bits-index>
+     * MPLS Interface Groups have <4bits-9><4bits:0><24bits-index>
+     * L3 ECMP Groups have <4bits-7><28bits-index>
+     * L2 Flood Groups have <4bits-4><12bits-vlanid><16bits-index>
+     * L3 VPN Groups have <4bits-9><4bits-2><24bits-index>
      */
     private static final int L2INTERFACEMASK = 0x0;
     private static final int L3UNICASTMASK = 0x20000000;
-    //private static final int MPLSINTERFACEMASK = 0x90000000;
+    private static final int MPLSINTERFACEMASK = 0x90000000;
     private static final int L3ECMPMASK = 0x70000000;
     private static final int L2FLOODMASK = 0x40000000;
+    private static final int L3VPNMASK = 0x92000000;
 
     private final Logger log = getLogger(getClass());
     private ServiceDirectory serviceDirectory;
     protected FlowRuleService flowRuleService;
     private CoreService coreService;
-    private GroupService groupService;
-    private FlowObjectiveStore flowObjectiveStore;
+    protected GroupService groupService;
+    protected FlowObjectiveStore flowObjectiveStore;
     protected DeviceId deviceId;
     protected ApplicationId driverId;
     protected PacketService packetService;
     protected DeviceService deviceService;
     private InternalPacketProcessor processor = new InternalPacketProcessor();
-    private KryoNamespace appKryo = new KryoNamespace.Builder()
+    protected KryoNamespace appKryo = new KryoNamespace.Builder()
         .register(KryoNamespaces.API)
         .register(GroupKey.class)
         .register(DefaultGroupKey.class)
-        .register(OfdpaGroupChain.class)
+        .register(OfdpaNextGroup.class)
         .register(byte[].class)
+        .register(ArrayDeque.class)
         .build();
 
-    private Cache<GroupKey, OfdpaGroupChain> pendingNextObjectives;
-    private ConcurrentHashMap<GroupKey, GroupChainElem> pendingGroups;
+    private Cache<GroupKey, OfdpaNextGroup> pendingNextObjectives;
+    private ConcurrentHashMap<GroupKey, Set<GroupChainElem>> pendingGroups;
 
     private ScheduledExecutorService groupChecker =
             Executors.newScheduledThreadPool(2, groupedThreads("onos/pipeliner",
@@ -184,6 +184,8 @@
     Map<VlanId, Set<PortNumber>> vlan2Port = new ConcurrentHashMap<VlanId,
                                                         Set<PortNumber>>();
 
+    // index number for group creation
+    AtomicInteger l3vpnindex = new AtomicInteger(0);
 
 
     @Override
@@ -193,15 +195,16 @@
 
         pendingNextObjectives = CacheBuilder.newBuilder()
                 .expireAfterWrite(20, TimeUnit.SECONDS)
-                .removalListener((RemovalNotification<GroupKey, OfdpaGroupChain> notification) -> {
-                    if (notification.getCause() == RemovalCause.EXPIRED) {
-                        fail(notification.getValue().nextObjective(),
-                             ObjectiveError.GROUPINSTALLATIONFAILED);
-                    }
+                .removalListener((
+                     RemovalNotification<GroupKey, OfdpaNextGroup> notification) -> {
+                         if (notification.getCause() == RemovalCause.EXPIRED) {
+                             fail(notification.getValue().nextObjective(),
+                                  ObjectiveError.GROUPINSTALLATIONFAILED);
+                         }
                 }).build();
 
         groupChecker.scheduleAtFixedRate(new GroupChecker(), 0, 500, TimeUnit.MILLISECONDS);
-        pendingGroups = new ConcurrentHashMap<GroupKey, GroupChainElem>();
+        pendingGroups = new ConcurrentHashMap<GroupKey, Set<GroupChainElem>>();
 
         coreService = serviceDirectory.get(CoreService.class);
         flowRuleService = serviceDirectory.get(FlowRuleService.class);
@@ -285,22 +288,49 @@
 
     @Override
     public void next(NextObjective nextObjective) {
-        log.debug("Processing NextObjective id{} op{}", nextObjective.id(),
-                  nextObjective.op());
-        if (nextObjective.op() == Objective.Operation.REMOVE) {
-            if (nextObjective.next().isEmpty()) {
-                removeGroup(nextObjective);
-            } else {
-                removeBucketFromGroup(nextObjective);
-            }
-        } else if (nextObjective.op() == Objective.Operation.ADD) {
-            NextGroup nextGroup = flowObjectiveStore.getNextGroup(nextObjective.id());
+        NextGroup nextGroup = flowObjectiveStore.getNextGroup(nextObjective.id());
+        switch (nextObjective.op()) {
+        case ADD:
             if (nextGroup != null) {
+                log.warn("Cannot add next {} that already exists in device {}",
+                         nextObjective.id(), deviceId);
+                return;
+            }
+            log.debug("Processing NextObjective id{} in dev{} - add group",
+                      nextObjective.id(), deviceId);
+            addGroup(nextObjective);
+            break;
+        case ADD_TO_EXISTING:
+            if (nextGroup != null) {
+                log.debug("Processing NextObjective id{} in dev{} - add bucket",
+                          nextObjective.id(), deviceId);
                 addBucketToGroup(nextObjective);
             } else {
-                addGroup(nextObjective);
+                // it is possible that group-chain has not been fully created yet
+                waitToAddBucketToGroup(nextObjective);
             }
-        } else {
+            break;
+        case REMOVE:
+            if (nextGroup == null) {
+                log.warn("Cannot remove next {} that does not exist in device {}",
+                         nextObjective.id(), deviceId);
+                return;
+            }
+            log.debug("Processing NextObjective id{}  in dev{} - remove group",
+                      nextObjective.id(), deviceId);
+            removeGroup(nextObjective);
+            break;
+        case REMOVE_FROM_EXISTING:
+            if (nextGroup == null) {
+                log.warn("Cannot remove from next {} that does not exist in device {}",
+                         nextObjective.id(), deviceId);
+                return;
+            }
+            log.debug("Processing NextObjective id{} in dev{} - remove bucket",
+                      nextObjective.id(), deviceId);
+            removeBucketFromGroup(nextObjective);
+            break;
+        default:
             log.warn("Unsupported operation {}", nextObjective.op());
         }
     }
@@ -309,7 +339,6 @@
     //  Flow handling
     //////////////////////////////////////
 
-
     /**
      * As per OFDPA 2.0 TTP, filtering of VLAN ids, MAC addresses (for routing)
      * and IP addresses configured on switch ports happen in different tables.
@@ -520,7 +549,6 @@
     /**
      * Allows routed packets with correct destination MAC to be directed
      * to unicast-IP routing table or MPLS forwarding table.
-     * XXX need to add rule for multicast routing.
      *
      * @param portCriterion  port on device for which this filter is programmed
      * @param ethCriterion   dstMac of device for which is filter is programmed
@@ -661,38 +689,78 @@
 
     /**
      * In the OF-DPA 2.0 pipeline, specific forwarding refers to the IP table
-     * (unicast or multicast) or the L2 table (mac + vlan).
+     * (unicast or multicast) or the L2 table (mac + vlan) or the MPLS table.
      *
      * @param fwd the forwarding objective of type 'specific'
      * @return    a collection of flow rules. Typically there will be only one
      *            for this type of forwarding objective. An empty set may be
      *            returned if there is an issue in processing the objective.
      */
-    private Collection<FlowRule> processSpecific(ForwardingObjective fwd) {
-        log.debug("Processing specific forwarding objective");
+    protected Collection<FlowRule> processSpecific(ForwardingObjective fwd) {
         TrafficSelector selector = fwd.selector();
         EthTypeCriterion ethType =
                 (EthTypeCriterion) selector.getCriterion(Criterion.Type.ETH_TYPE);
-        // XXX currently supporting only the L3 unicast table
-        if (ethType == null || ethType.ethType().toShort() != Ethernet.TYPE_IPV4) {
+        if ((ethType == null) ||
+                (ethType.ethType().toShort() != Ethernet.TYPE_IPV4) &&
+                (ethType.ethType().toShort() != Ethernet.MPLS_UNICAST)) {
+            log.warn("processSpecific: Unsupported "
+                    + "forwarding objective criteraia");
             fail(fwd, ObjectiveError.UNSUPPORTED);
             return Collections.emptySet();
         }
 
-        TrafficSelector filteredSelector =
-                DefaultTrafficSelector.builder()
-                        .matchEthType(Ethernet.TYPE_IPV4)
-                        .matchIPDst(
-                                ((IPCriterion)
-                                        selector.getCriterion(Criterion.Type.IPV4_DST)).ip())
-                        .build();
+        int forTableId = -1;
+        TrafficSelector.Builder filteredSelector = DefaultTrafficSelector.builder();
+        if (ethType.ethType().toShort() == Ethernet.TYPE_IPV4) {
+            filteredSelector.matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPDst(((IPCriterion)
+                        selector.getCriterion(Criterion.Type.IPV4_DST)).ip());
+            forTableId = UNICAST_ROUTING_TABLE;
+            log.debug("processing IPv4 specific forwarding objective {} in dev:{}",
+                      fwd.id(), deviceId);
+        } else {
+            filteredSelector
+                .matchEthType(Ethernet.MPLS_UNICAST)
+                .matchMplsLabel(((MplsCriterion)
+                        selector.getCriterion(Criterion.Type.MPLS_LABEL)).label());
+            MplsBosCriterion bos = (MplsBosCriterion) selector
+                                        .getCriterion(Criterion.Type.MPLS_BOS);
+            if (bos != null) {
+                filteredSelector.matchMplsBos(bos.mplsBos());
+            }
+            forTableId = MPLS_TABLE_1;
+            log.debug("processing MPLS specific forwarding objective {} in dev {}",
+                      fwd.id(), deviceId);
+        }
 
         TrafficTreatment.Builder tb = DefaultTrafficTreatment.builder();
+        boolean popMpls = false;
+        if (fwd.treatment() != null) {
+            for (Instruction i : fwd.treatment().allInstructions()) {
+                tb.add(i);
+                if (i instanceof L2ModificationInstruction &&
+                    ((L2ModificationInstruction) i).subtype() == L2SubType.MPLS_POP) {
+                        popMpls = true;
+                }
+            }
+        }
 
         if (fwd.nextId() != null) {
+            if (forTableId == MPLS_TABLE_1 && !popMpls) {
+                log.warn("SR CONTINUE case cannot be handled as MPLS ECMP "
+                        + "is not implemented in OF-DPA yet. Aborting this flow "
+                        + "in this device {}", deviceId);
+                // XXX We could convert to forwarding to a single-port, via a
+                // MPLS interface, or a MPLS SWAP (with-same) but that would
+                // have to be handled in the next-objective. Also the pop-mpls
+                // logic used here won't work in non-BoS case.
+                return Collections.emptySet();
+            }
+
             NextGroup next = flowObjectiveStore.getNextGroup(fwd.nextId());
-            List<GroupKey> gkeys = appKryo.deserialize(next.data());
-            Group group = groupService.getGroup(deviceId, gkeys.get(0));
+            List<Deque<GroupKey>> gkeys = appKryo.deserialize(next.data());
+            // we only need the top level group's key to point the flow to it
+            Group group = groupService.getGroup(deviceId, gkeys.get(0).peekFirst());
             if (group == null) {
                 log.warn("The group left!");
                 fail(fwd, ObjectiveError.GROUPMISSING);
@@ -705,8 +773,9 @@
                 .fromApp(fwd.appId())
                 .withPriority(fwd.priority())
                 .forDevice(deviceId)
-                .withSelector(filteredSelector)
-                .withTreatment(tb.build());
+                .withSelector(filteredSelector.build())
+                .withTreatment(tb.build())
+                .forTable(forTableId);
 
         if (fwd.permanent()) {
             ruleBuilder.makePermanent();
@@ -714,7 +783,6 @@
             ruleBuilder.makeTemporary(fwd.timeout());
         }
 
-        ruleBuilder.forTable(UNICAST_ROUTING_TABLE);
         return Collections.singletonList(ruleBuilder.build());
     }
 
@@ -724,7 +792,7 @@
         }
     }
 
-    private void fail(Objective obj, ObjectiveError error) {
+    protected void fail(Objective obj, ObjectiveError error) {
         if (obj.context().isPresent()) {
             obj.context().get().onError(obj, error);
         }
@@ -765,20 +833,66 @@
 
     /**
      * As per the OFDPA 2.0 TTP, packets are sent out of ports by using
-     * a chain of groups, namely an L3 Unicast Group that points to an L2 Interface
-     * Group which in-turn points to an output port. The Next Objective passed
+     * a chain of groups. The simple Next Objective passed
      * in by the application has to be broken up into a group chain
-     * to satisfy this TTP.
+     * comprising of an L3 Unicast Group that points to an L2 Interface
+     * Group which in-turn points to an output port. In some cases, the simple
+     * next Objective can just be an L2 interface without the need for chaining.
      *
      * @param nextObj  the nextObjective of type SIMPLE
      */
     private void processSimpleNextObjective(NextObjective nextObj) {
         // break up simple next objective to GroupChain objects
         TrafficTreatment treatment = nextObj.next().iterator().next();
+
+        GroupInfo groupInfo = createL2L3Chain(treatment, nextObj.id(),
+                                              nextObj.appId(), false,
+                                              nextObj.meta());
+        if (groupInfo == null) {
+            log.error("Could not process nextObj={} in dev:{}", nextObj.id(), deviceId);
+            return;
+        }
+        // create object for local and distributed storage
+        Deque<GroupKey> gkeyChain = new ArrayDeque<>();
+        gkeyChain.addFirst(groupInfo.innerGrpDesc.appCookie());
+        gkeyChain.addFirst(groupInfo.outerGrpDesc.appCookie());
+        OfdpaNextGroup ofdpaGrp = new OfdpaNextGroup(
+                                           Collections.singletonList(gkeyChain),
+                                           nextObj);
+
+        // store l3groupkey with the ofdpaGroupChain for the nextObjective that depends on it
+        pendingNextObjectives.put(groupInfo.outerGrpDesc.appCookie(), ofdpaGrp);
+
+        // now we are ready to send the l2 groupDescription (inner), as all the stores
+        // that will get async replies have been updated. By waiting to update
+        // the stores, we prevent nasty race conditions.
+        groupService.addGroup(groupInfo.innerGrpDesc);
+    }
+
+    /**
+     * Creates one of two possible group-chains from the treatment
+     * passed in. Depending on the MPLS boolean, this method either creates
+     * an L3Unicast Group --> L2Interface Group, if mpls is false;
+     * or MPLSInterface Group --> L2Interface Group, if mpls is true;
+     * The returned 'inner' group description is always the L2 Interface group.
+     *
+     * @param treatment that needs to be broken up to create the group chain
+     * @param nextId of the next objective that needs this group chain
+     * @param appId of the application that sent this next objective
+     * @param mpls determines if L3Unicast or MPLSInterface group is created
+     * @param meta metadata passed in by the application as part of the nextObjective
+     * @return GroupInfo containing the GroupDescription of the
+     *         L2Interface group(inner) and the GroupDescription of the (outer)
+     *         L3Unicast/MPLSInterface group. May return null if there is an
+     *         error in processing the chain
+     */
+    private GroupInfo createL2L3Chain(TrafficTreatment treatment, int nextId,
+                                      ApplicationId appId, boolean mpls,
+                                      TrafficSelector meta) {
         // for the l2interface group, get vlan and port info
-        // for the l3unicast group, get the src/dst mac and vlan info
-        TrafficTreatment.Builder l3utt = DefaultTrafficTreatment.builder();
-        TrafficTreatment.Builder l2itt = DefaultTrafficTreatment.builder();
+        // for the outer group, get the src/dst mac, and vlan info
+        TrafficTreatment.Builder outerTtb = DefaultTrafficTreatment.builder();
+        TrafficTreatment.Builder innerTtb = DefaultTrafficTreatment.builder();
         VlanId vlanid = null;
         long portNum = 0;
         for (Instruction ins : treatment.allInstructions()) {
@@ -786,76 +900,144 @@
                 L2ModificationInstruction l2ins = (L2ModificationInstruction) ins;
                 switch (l2ins.subtype()) {
                 case ETH_DST:
-                    l3utt.setEthDst(((ModEtherInstruction) l2ins).mac());
+                    outerTtb.setEthDst(((ModEtherInstruction) l2ins).mac());
                     break;
                 case ETH_SRC:
-                    l3utt.setEthSrc(((ModEtherInstruction) l2ins).mac());
+                    outerTtb.setEthSrc(((ModEtherInstruction) l2ins).mac());
                     break;
                 case VLAN_ID:
                     vlanid = ((ModVlanIdInstruction) l2ins).vlanId();
-                    l3utt.setVlanId(vlanid);
+                    outerTtb.setVlanId(vlanid);
+                    break;
+                case VLAN_POP:
+                    innerTtb.popVlan();
                     break;
                 case DEC_MPLS_TTL:
                 case MPLS_LABEL:
                 case MPLS_POP:
                 case MPLS_PUSH:
                 case VLAN_PCP:
-                case VLAN_POP:
                 case VLAN_PUSH:
                 default:
                     break;
                 }
             } else if (ins.type() == Instruction.Type.OUTPUT) {
                 portNum = ((OutputInstruction) ins).port().toLong();
-                l2itt.add(ins);
+                innerTtb.add(ins);
             } else {
                 log.warn("Driver does not handle this type of TrafficTreatment"
                         + " instruction in nextObjectives:  {}", ins.type());
             }
         }
 
+        if (vlanid == null) {
+            //use the vlanid associated with the port
+            vlanid = port2Vlan.get(PortNumber.portNumber(portNum));
+        }
+
+        if (vlanid == null) {
+            // use metadata
+            for (Criterion metaCriterion : meta.criteria()) {
+                if (metaCriterion.type() == Type.VLAN_VID) {
+                    vlanid = ((VlanIdCriterion) metaCriterion).vlanId();
+                }
+            }
+        }
+
+        if (vlanid == null) {
+            log.error("Driver cannot process an L2/L3 group chain without "
+                    + "egress vlan information for dev: {} port:{}",
+                    deviceId, portNum);
+            return null;
+        }
+
         // assemble information for ofdpa l2interface group
-        int l2gk = nextObj.id() | GROUP1MASK;
-        final GroupKey l2groupkey = new DefaultGroupKey(appKryo.serialize(l2gk));
         Integer l2groupId = L2INTERFACEMASK | (vlanid.toShort() << 16) | (int) portNum;
+        // a globally unique groupkey that is different for ports in the same devices
+        // but different for the same portnumber on different devices. Also different
+        // for the various group-types created out of the same next objective.
+        int l2gk = 0x0ffffff & (deviceId.hashCode() << 8 | (int) portNum);
+        final GroupKey l2groupkey = new DefaultGroupKey(appKryo.serialize(l2gk));
 
-        // assemble information for ofdpa l3unicast group
-        int l3gk = nextObj.id() | GROUP0MASK;
-        final GroupKey l3groupkey = new DefaultGroupKey(appKryo.serialize(l3gk));
-        Integer l3groupId = L3UNICASTMASK | (int) portNum;
-        l3utt.group(new DefaultGroupId(l2groupId));
-        GroupChainElem gce = new GroupChainElem(l3groupkey, l3groupId,
-                                                GroupDescription.Type.INDIRECT,
-                                                Collections.singletonList(l3utt.build()),
-                                                nextObj.appId(), 1);
+        // assemble information for outer group
+        GroupDescription outerGrpDesc = null;
+        if (mpls) {
+            // outer group is MPLSInteface
+            Integer mplsgroupId = MPLSINTERFACEMASK | (int) portNum;
+            // using mplsinterfacemask in groupkey to differentiate from l2interface
+            int mplsgk = MPLSINTERFACEMASK | (0x0ffffff & (deviceId.hashCode() << 8 | (int) portNum));
+            final GroupKey mplsgroupkey = new DefaultGroupKey(appKryo.serialize(mplsgk));
+            outerTtb.group(new DefaultGroupId(l2groupId));
+            // create the mpls-interface group description to wait for the
+            // l2 interface group to be processed
+            GroupBucket mplsinterfaceGroupBucket =
+                    DefaultGroupBucket.createIndirectGroupBucket(outerTtb.build());
+            outerGrpDesc = new DefaultGroupDescription(
+                                   deviceId,
+                                   GroupDescription.Type.INDIRECT,
+                                   new GroupBuckets(Collections.singletonList(
+                                                        mplsinterfaceGroupBucket)),
+                                   mplsgroupkey,
+                                   mplsgroupId,
+                                   appId);
+            log.debug("Trying MPLS-Interface: device:{} gid:{} gkey:{} nextid:{}",
+                      deviceId, Integer.toHexString(mplsgroupId),
+                      mplsgroupkey, nextId);
+        } else {
+            // outer group is L3Unicast
+            Integer l3groupId = L3UNICASTMASK | (int) portNum;
+            int l3gk = L3UNICASTMASK | (0x0ffffff & (deviceId.hashCode() << 8 | (int) portNum));
+            final GroupKey l3groupkey = new DefaultGroupKey(appKryo.serialize(l3gk));
+            outerTtb.group(new DefaultGroupId(l2groupId));
+            // create the l3unicast group description to wait for the
+            // l2 interface group to be processed
+            GroupBucket l3unicastGroupBucket =
+                    DefaultGroupBucket.createIndirectGroupBucket(outerTtb.build());
+            outerGrpDesc = new DefaultGroupDescription(
+                                   deviceId,
+                                   GroupDescription.Type.INDIRECT,
+                                   new GroupBuckets(Collections.singletonList(
+                                                        l3unicastGroupBucket)),
+                                   l3groupkey,
+                                   l3groupId,
+                                   appId);
+            log.debug("Trying L3Unicast: device:{} gid:{} gkey:{} nextid:{}",
+                      deviceId, Integer.toHexString(l3groupId),
+                      l3groupkey, nextId);
+        }
 
-        // create object for local and distributed storage
-        List<GroupKey> gkeys = new ArrayList<GroupKey>();
-        gkeys.add(l3groupkey); // group0 in chain
-        gkeys.add(l2groupkey); // group1 in chain
-        OfdpaGroupChain ofdpaGrp = new OfdpaGroupChain(gkeys, nextObj);
+        // store l2groupkey with the groupChainElem for the outer-group that depends on it
+        GroupChainElem gce = new GroupChainElem(outerGrpDesc, 1);
+        Set<GroupChainElem> gceSet = Collections.newSetFromMap(
+                                         new ConcurrentHashMap<GroupChainElem, Boolean>());
+        gceSet.add(gce);
+        Set<GroupChainElem> retval = pendingGroups.putIfAbsent(l2groupkey, gceSet);
+        if (retval != null) {
+            retval.add(gce);
+        }
 
-        // store l2groupkey with the groupChainElem for the l3group that depends on it
-        pendingGroups.put(l2groupkey, gce);
+        // create group description for the inner l2interfacegroup
+        GroupBucket l2interfaceGroupBucket =
+                DefaultGroupBucket.createIndirectGroupBucket(innerTtb.build());
+        GroupDescription l2groupDescription =
+                             new DefaultGroupDescription(
+                                     deviceId,
+                                     GroupDescription.Type.INDIRECT,
+                                     new GroupBuckets(Collections.singletonList(
+                                                          l2interfaceGroupBucket)),
+                                     l2groupkey,
+                                     l2groupId,
+                                     appId);
+        log.debug("Trying L2Interface: device:{} gid:{} gkey:{} nextId:{}",
+                  deviceId, Integer.toHexString(l2groupId),
+                  l2groupkey, nextId);
+        return new GroupInfo(l2groupDescription, outerGrpDesc);
 
-        // store l3groupkey with the ofdpaGroupChain for the nextObjective that depends on it
-        pendingNextObjectives.put(l3groupkey, ofdpaGrp);
-
-        // create group description for the ofdpa l2interfacegroup and send to groupservice
-        GroupBucket bucket =
-                DefaultGroupBucket.createIndirectGroupBucket(l2itt.build());
-        GroupDescription groupDescription = new DefaultGroupDescription(deviceId,
-                             GroupDescription.Type.INDIRECT,
-                             new GroupBuckets(Collections.singletonList(bucket)),
-                             l2groupkey,
-                             l2groupId,
-                             nextObj.appId());
-        groupService.addGroup(groupDescription);
     }
 
     /**
      * As per the OFDPA 2.0 TTP, packets are sent out of ports by using
-     * a chain of groups. The Next Objective passed in by the application
+     * a chain of groups. The broadcast Next Objective passed in by the application
      * has to be broken up into a group chain comprising of an
      * L2 Flood group whose buckets point to L2 Interface groups.
      *
@@ -866,9 +1048,9 @@
         Collection<TrafficTreatment> buckets = nextObj.next();
 
         // each treatment is converted to an L2 interface group
-        int indicator = 0;
         VlanId vlanid = null;
-        List<GroupInfo> groupInfoCollection = new ArrayList<>();
+        List<GroupDescription> l2interfaceGroupDescs = new ArrayList<>();
+        List<Deque<GroupKey>> allGroupKeys = new ArrayList<>();
         for (TrafficTreatment treatment : buckets) {
             TrafficTreatment.Builder newTreatment = DefaultTrafficTreatment.builder();
             PortNumber portNum = null;
@@ -907,83 +1089,284 @@
                 }
             }
 
-            // assemble info for all l2 interface groups
-            indicator += GROUP1MASK;
-            int l2gk = nextObj.id() | indicator;
+            // assemble info for l2 interface group
+            int l2gk = 0x0ffffff & (deviceId.hashCode() << 8 | (int) portNum.toLong());
             final GroupKey l2groupkey = new DefaultGroupKey(appKryo.serialize(l2gk));
             Integer l2groupId = L2INTERFACEMASK | (vlanid.toShort() << 16) |
                                     (int) portNum.toLong();
-            GroupBucket newbucket =
+            GroupBucket l2interfaceGroupBucket =
                     DefaultGroupBucket.createIndirectGroupBucket(newTreatment.build());
+            GroupDescription l2interfaceGroupDescription =
+                        new DefaultGroupDescription(
+                                                    deviceId,
+                            GroupDescription.Type.INDIRECT,
+                            new GroupBuckets(Collections.singletonList(
+                                                 l2interfaceGroupBucket)),
+                            l2groupkey,
+                            l2groupId,
+                            nextObj.appId());
+            log.debug("Trying L2-Interface: device:{} gid:{} gkey:{} nextid:{}",
+                      deviceId, Integer.toHexString(l2groupId),
+                      l2groupkey, nextObj.id());
+
+            Deque<GroupKey> gkeyChain = new ArrayDeque<>();
+            gkeyChain.addFirst(l2groupkey);
 
             // store the info needed to create this group
-            groupInfoCollection.add(new GroupInfo(l2groupId, l2groupkey, newbucket));
+            l2interfaceGroupDescs.add(l2interfaceGroupDescription);
+            allGroupKeys.add(gkeyChain);
         }
 
         // assemble info for l2 flood group
-        int l2floodgk = nextObj.id() | GROUP0MASK;
-        final GroupKey l2floodgroupkey = new DefaultGroupKey(appKryo.serialize(l2floodgk));
         Integer l2floodgroupId = L2FLOODMASK | (vlanid.toShort() << 16) | nextObj.id();
-        // collection of treatment with groupids of l2 interface groups
-        List<TrafficTreatment> floodtt = new ArrayList<>();
-        for (GroupInfo gi : groupInfoCollection) {
+        int l2floodgk = L2FLOODMASK | nextObj.id() << 12;
+        final GroupKey l2floodgroupkey = new DefaultGroupKey(appKryo.serialize(l2floodgk));
+        // collection of group buckets pointing to all the l2 interface groups
+        List<GroupBucket> l2floodBuckets = new ArrayList<>();
+        for (GroupDescription l2intGrpDesc : l2interfaceGroupDescs) {
             TrafficTreatment.Builder ttb = DefaultTrafficTreatment.builder();
-            ttb.group(new DefaultGroupId(gi.groupId));
-            floodtt.add(ttb.build());
+            ttb.group(new DefaultGroupId(l2intGrpDesc.givenGroupId()));
+            GroupBucket abucket = DefaultGroupBucket.createAllGroupBucket(ttb.build());
+            l2floodBuckets.add(abucket);
         }
-        GroupChainElem gce = new GroupChainElem(l2floodgroupkey, l2floodgroupId,
-                                                GroupDescription.Type.ALL,
-                                                floodtt,
-                                                nextObj.appId(),
-                                                groupInfoCollection.size());
+        // create the l2flood group-description to wait for all the
+        // l2interface groups to be processed
+        GroupDescription l2floodGroupDescription =
+                                new DefaultGroupDescription(
+                                        deviceId,
+                                        GroupDescription.Type.ALL,
+                                        new GroupBuckets(l2floodBuckets),
+                                        l2floodgroupkey,
+                                        l2floodgroupId,
+                                        nextObj.appId());
+        GroupChainElem gce = new GroupChainElem(l2floodGroupDescription,
+                                                l2interfaceGroupDescs.size());
+        log.debug("Trying L2-Flood: device:{} gid:{} gkey:{} nextid:{}",
+                  deviceId, Integer.toHexString(l2floodgroupId),
+                  l2floodgroupkey, nextObj.id());
 
         // create objects for local and distributed storage
-        List<GroupKey> gkeys = new ArrayList<GroupKey>();
-        gkeys.add(l2floodgroupkey); // group0 in chain
-        OfdpaGroupChain ofdpaGrp = new OfdpaGroupChain(gkeys, nextObj);
+        allGroupKeys.forEach(gkeyChain -> gkeyChain.addFirst(l2floodgroupkey));
+        OfdpaNextGroup ofdpaGrp = new OfdpaNextGroup(allGroupKeys, nextObj);
 
         // store l2floodgroupkey with the ofdpaGroupChain for the nextObjective
         // that depends on it
         pendingNextObjectives.put(l2floodgroupkey, ofdpaGrp);
 
-        for (GroupInfo gi : groupInfoCollection) {
+        for (GroupDescription l2intGrpDesc : l2interfaceGroupDescs) {
             // store all l2groupkeys with the groupChainElem for the l2floodgroup
             // that depends on it
-            pendingGroups.put(gi.groupKey, gce);
+            Set<GroupChainElem> gceSet = Collections.newSetFromMap(
+                                             new ConcurrentHashMap<GroupChainElem, Boolean>());
+            gceSet.add(gce);
+            Set<GroupChainElem> retval = pendingGroups.putIfAbsent(
+                                             l2intGrpDesc.appCookie(), gceSet);
+            if (retval != null) {
+                retval.add(gce);
+            }
 
             // create and send groups for all l2 interface groups
-            GroupDescription groupDescription =
-                    new DefaultGroupDescription(
-                            deviceId,
-                            GroupDescription.Type.INDIRECT,
-                            new GroupBuckets(Collections.singletonList(gi.groupBucket)),
-                            gi.groupKey,
-                            gi.groupId,
-                            nextObj.appId());
-            groupService.addGroup(groupDescription);
+            groupService.addGroup(l2intGrpDesc);
         }
     }
 
+    /**
+     * Utility class for moving group information around.
+     *
+     */
     private class GroupInfo {
-        private Integer groupId;
-        private GroupKey groupKey;
-        private GroupBucket groupBucket;
+        private GroupDescription innerGrpDesc;
+        private GroupDescription outerGrpDesc;
 
-        GroupInfo(Integer groupId, GroupKey groupKey, GroupBucket groupBucket) {
-            this.groupBucket = groupBucket;
-            this.groupId = groupId;
-            this.groupKey = groupKey;
+        GroupInfo(GroupDescription innerGrpDesc, GroupDescription outerGrpDesc) {
+            this.innerGrpDesc = innerGrpDesc;
+            this.outerGrpDesc = outerGrpDesc;
         }
     }
 
+    /**
+     * As per the OFDPA 2.0 TTP, packets are sent out of ports by using
+     * a chain of groups. The hashed Next Objective passed in by the application
+     * has to be broken up into a group chain comprising of an
+     * L3 ECMP group as the top level group. Buckets of this group can point
+     * to a variety of groups in a group chain, depending on the whether
+     * MPLS labels are being pushed or not.
+     * <p>
+     * NOTE: We do not create MPLS ECMP groups as they are unimplemented in
+     *       OF-DPA 2.0 (even though it is in the spec). Therefore we do not
+     *       check the nextObjective meta.
+     *
+     * @param nextObj  the nextObjective of type HASHED
+     */
     private void processHashedNextObjective(NextObjective nextObj) {
-        // TODO Auto-generated method stub
+        // break up hashed next objective to multiple groups
+        Collection<TrafficTreatment> buckets = nextObj.next();
+
+        // storage for all group keys in the chain of groups created
+        List<Deque<GroupKey>> allGroupKeys = new ArrayList<>();
+        List<GroupInfo> unsentGroups = new ArrayList<>();
+        for (TrafficTreatment bucket : buckets) {
+            //figure out how many labels are pushed in each bucket
+            int labelsPushed = 0;
+            MplsLabel innermostLabel = null;
+            for (Instruction ins : bucket.allInstructions()) {
+                if (ins.type() == Instruction.Type.L2MODIFICATION) {
+                    L2ModificationInstruction l2ins = (L2ModificationInstruction) ins;
+                    if (l2ins.subtype() == L2SubType.MPLS_PUSH) {
+                        labelsPushed++;
+                    }
+                    if (l2ins.subtype() == L2SubType.MPLS_LABEL) {
+                        if (innermostLabel == null) {
+                            innermostLabel = ((ModMplsLabelInstruction) l2ins).mplsLabel();
+                        }
+                    }
+                }
+            }
+
+            Deque<GroupKey> gkeyChain = new ArrayDeque<>();
+            // XXX we only deal with 0 and 1 label push right now
+            if (labelsPushed == 0) {
+                GroupInfo nolabelGroupInfo = createL2L3Chain(bucket, nextObj.id(),
+                                                             nextObj.appId(), false,
+                                                             nextObj.meta());
+                if (nolabelGroupInfo == null) {
+                    log.error("Could not process nextObj={} in dev:{}",
+                              nextObj.id(), deviceId);
+                    return;
+                }
+                gkeyChain.addFirst(nolabelGroupInfo.innerGrpDesc.appCookie());
+                gkeyChain.addFirst(nolabelGroupInfo.outerGrpDesc.appCookie());
+
+                // we can't send the inner group description yet, as we have to
+                // create the dependent ECMP group first. So we store..
+                unsentGroups.add(nolabelGroupInfo);
+
+            } else if (labelsPushed == 1) {
+                GroupInfo onelabelGroupInfo = createL2L3Chain(bucket, nextObj.id(),
+                                                              nextObj.appId(), true,
+                                                              nextObj.meta());
+                if (onelabelGroupInfo == null) {
+                    log.error("Could not process nextObj={} in dev:{}",
+                              nextObj.id(), deviceId);
+                    return;
+                }
+                // we need to add another group to this chain - the L3VPN group
+                TrafficTreatment.Builder l3vpnTtb = DefaultTrafficTreatment.builder();
+                l3vpnTtb.pushMpls()
+                            .setMpls(innermostLabel)
+                            .setMplsBos(true)
+                            .copyTtlOut()
+                            .group(new DefaultGroupId(
+                                 onelabelGroupInfo.outerGrpDesc.givenGroupId()));
+                GroupBucket l3vpnGrpBkt  =
+                        DefaultGroupBucket.createIndirectGroupBucket(l3vpnTtb.build());
+                int l3vpngroupId = L3VPNMASK | l3vpnindex.incrementAndGet();
+                int l3vpngk = L3VPNMASK | nextObj.id() << 12 | l3vpnindex.get();
+                GroupKey l3vpngroupkey = new DefaultGroupKey(appKryo.serialize(l3vpngk));
+                GroupDescription l3vpnGroupDesc =
+                        new DefaultGroupDescription(
+                                deviceId,
+                                GroupDescription.Type.INDIRECT,
+                                new GroupBuckets(Collections.singletonList(
+                                                     l3vpnGrpBkt)),
+                                l3vpngroupkey,
+                                l3vpngroupId,
+                                nextObj.appId());
+                GroupChainElem l3vpnGce = new GroupChainElem(l3vpnGroupDesc, 1);
+                Set<GroupChainElem> gceSet = Collections.newSetFromMap(
+                                                 new ConcurrentHashMap<GroupChainElem, Boolean>());
+                gceSet.add(l3vpnGce);
+                Set<GroupChainElem> retval = pendingGroups
+                        .putIfAbsent(onelabelGroupInfo.outerGrpDesc.appCookie(), gceSet);
+                if (retval != null) {
+                    retval.add(l3vpnGce);
+                }
+
+                gkeyChain.addFirst(onelabelGroupInfo.innerGrpDesc.appCookie());
+                gkeyChain.addFirst(onelabelGroupInfo.outerGrpDesc.appCookie());
+                gkeyChain.addFirst(l3vpngroupkey);
+
+                //now we can replace the outerGrpDesc with the one we just created
+                onelabelGroupInfo.outerGrpDesc = l3vpnGroupDesc;
+
+                // we can't send the innermost group yet, as we have to create
+                // the dependent ECMP group first. So we store ...
+                unsentGroups.add(onelabelGroupInfo);
+
+                log.debug("Trying L3VPN: device:{} gid:{} gkey:{} nextId:{}",
+                          deviceId, Integer.toHexString(l3vpngroupId),
+                          l3vpngroupkey, nextObj.id());
+
+            } else {
+                log.warn("Driver currently does not handle more than 1 MPLS "
+                        + "labels. Not processing nextObjective {}", nextObj);
+                return;
+            }
+
+            // all groups in this chain
+            allGroupKeys.add(gkeyChain);
+        }
+
+        // now we can create the outermost L3 ECMP group
+        List<GroupBucket> l3ecmpGroupBuckets = new ArrayList<>();
+        for (GroupInfo gi : unsentGroups) {
+            // create ECMP bucket to point to the outer group
+            TrafficTreatment.Builder ttb = DefaultTrafficTreatment.builder();
+            ttb.group(new DefaultGroupId(gi.outerGrpDesc.givenGroupId()));
+            GroupBucket sbucket = DefaultGroupBucket
+                    .createSelectGroupBucket(ttb.build());
+            l3ecmpGroupBuckets.add(sbucket);
+        }
+        int l3ecmpGroupId = L3ECMPMASK | nextObj.id() << 12;
+        GroupKey l3ecmpGroupKey = new DefaultGroupKey(appKryo.serialize(l3ecmpGroupId));
+        GroupDescription l3ecmpGroupDesc =
+                new DefaultGroupDescription(
+                        deviceId,
+                        GroupDescription.Type.SELECT,
+                        new GroupBuckets(l3ecmpGroupBuckets),
+                        l3ecmpGroupKey,
+                        l3ecmpGroupId,
+                        nextObj.appId());
+        GroupChainElem l3ecmpGce = new GroupChainElem(l3ecmpGroupDesc,
+                                                      l3ecmpGroupBuckets.size());
+
+        // create objects for local and distributed storage
+        allGroupKeys.forEach(gkeyChain -> gkeyChain.addFirst(l3ecmpGroupKey));
+        OfdpaNextGroup ofdpaGrp = new OfdpaNextGroup(allGroupKeys, nextObj);
+
+        // store l3ecmpGroupKey with the ofdpaGroupChain for the nextObjective
+        // that depends on it
+        pendingNextObjectives.put(l3ecmpGroupKey, ofdpaGrp);
+
+        log.debug("Trying L3ECMP: device:{} gid:{} gkey:{} nextId:{}",
+                  deviceId, Integer.toHexString(l3ecmpGroupId),
+                  l3ecmpGroupKey, nextObj.id());
+        // finally we are ready to send the innermost groups
+        for (GroupInfo gi : unsentGroups) {
+            log.debug("Sending innermost group {} in group chain on device {} ",
+                      Integer.toHexString(gi.innerGrpDesc.givenGroupId()), deviceId);
+            Set<GroupChainElem> gceSet = Collections.newSetFromMap(
+                                             new ConcurrentHashMap<GroupChainElem, Boolean>());
+            gceSet.add(l3ecmpGce);
+            Set<GroupChainElem> retval = pendingGroups
+                    .putIfAbsent(gi.outerGrpDesc.appCookie(), gceSet);
+            if (retval != null) {
+                retval.add(l3ecmpGce);
+            }
+
+            groupService.addGroup(gi.innerGrpDesc);
+        }
+
     }
 
     private void addBucketToGroup(NextObjective nextObjective) {
         // TODO Auto-generated method stub
     }
 
+    private void waitToAddBucketToGroup(NextObjective nextObjective) {
+        // TODO Auto-generated method stub
+    }
+
     private void removeBucketFromGroup(NextObjective nextObjective) {
         // TODO Auto-generated method stub
     }
@@ -1009,45 +1392,11 @@
     private void processGroupChain(GroupChainElem gce) {
         int waitOnGroups = gce.decrementAndGetGroupsWaitedOn();
         if (waitOnGroups != 0) {
-            log.debug("GCE: {} waiting on {} groups. Not processing yet",
-                      gce, waitOnGroups);
+            log.debug("GCE: {} not ready to be processed", gce);
             return;
         }
-        List<GroupBucket> buckets = new ArrayList<>();
-        switch (gce.groupType) {
-        case INDIRECT:
-            GroupBucket ibucket = DefaultGroupBucket
-                .createIndirectGroupBucket(gce.bucketActions.iterator().next());
-            buckets.add(ibucket);
-            break;
-        case ALL:
-            for (TrafficTreatment tt : gce.bucketActions) {
-                GroupBucket abucket = DefaultGroupBucket
-                        .createAllGroupBucket(tt);
-                buckets.add(abucket);
-            }
-            break;
-        case SELECT:
-            for (TrafficTreatment tt : gce.bucketActions) {
-                GroupBucket sbucket = DefaultGroupBucket
-                        .createSelectGroupBucket(tt);
-                buckets.add(sbucket);
-            }
-            break;
-        case FAILOVER:
-        default:
-            log.error("Unknown or unimplemented GroupChainElem {}", gce);
-        }
-
-        if (buckets.size() > 0) {
-            GroupDescription groupDesc = new DefaultGroupDescription(
-                                                 deviceId, gce.groupType,
-                                                 new GroupBuckets(buckets),
-                                                 gce.gkey,
-                                                 gce.givenGroupId,
-                                                 gce.appId);
-            groupService.addGroup(groupDesc);
-        }
+        log.debug("GCE: {} ready to be processed", gce);
+        groupService.addGroup(gce.groupDescription);
     }
 
     private class GroupChecker implements Runnable {
@@ -1063,19 +1412,23 @@
 
             keys.stream().forEach(key -> {
                 //first check for group chain
-                GroupChainElem gce = pendingGroups.remove(key);
-                if (gce != null) {
-                    log.info("Group service processed group key {}. Processing next "
-                            + "group in group chain with group key {}",
-                            appKryo.deserialize(key.key()),
-                            appKryo.deserialize(gce.gkey.key()));
-                    processGroupChain(gce);
+                Set<GroupChainElem> gceSet = pendingGroups.remove(key);
+                if (gceSet != null) {
+                    for (GroupChainElem gce : gceSet) {
+                        log.info("Group service processed group key {} in device {}. "
+                                + "Processing next group in group chain with group id {}",
+                                key, deviceId,
+                                Integer.toHexString(gce.groupDescription.givenGroupId()));
+                        processGroupChain(gce);
+                    }
                 } else {
-                    OfdpaGroupChain obj = pendingNextObjectives.getIfPresent(key);
-                    log.info("Group service processed group key {}. Done implementing "
-                            + "next objective: {}", appKryo.deserialize(key.key()),
-                            obj.nextObjective().id());
+                    OfdpaNextGroup obj = pendingNextObjectives.getIfPresent(key);
                     if (obj != null) {
+                        log.info("Group service processed group key {} in device:{}. "
+                                + "Done implementing next objective: {} <<-->> gid:{}",
+                                key, deviceId, obj.nextObjective().id(),
+                                Integer.toHexString(groupService.getGroup(deviceId, key)
+                                                    .givenGroupId()));
                         pass(obj.nextObjective());
                         pendingNextObjectives.invalidate(key);
                         flowObjectiveStore.putNextGroup(obj.nextObjective().id(), obj);
@@ -1088,23 +1441,27 @@
     private class InnerGroupListener implements GroupListener {
         @Override
         public void event(GroupEvent event) {
-            log.debug("received group event of type {}", event.type());
+            log.trace("received group event of type {}", event.type());
             if (event.type() == GroupEvent.Type.GROUP_ADDED) {
                 GroupKey key = event.subject().appCookie();
                 // first check for group chain
-                GroupChainElem gce = pendingGroups.remove(key);
-                if (gce != null) {
-                    log.info("group ADDED with group key {} .. "
-                            + "Processing next group in group chain with group key {}",
-                            appKryo.deserialize(key.key()),
-                            appKryo.deserialize(gce.gkey.key()));
-                    processGroupChain(gce);
+                Set<GroupChainElem> gceSet = pendingGroups.remove(key);
+                if (gceSet != null) {
+                    for (GroupChainElem gce : gceSet) {
+                        log.info("group ADDED with group key {} .. "
+                                + "Processing next group in group chain with group key {}",
+                                key,
+                                gce.groupDescription.appCookie());
+                        processGroupChain(gce);
+                    }
                 } else {
-                    OfdpaGroupChain obj = pendingNextObjectives.getIfPresent(key);
+                    OfdpaNextGroup obj = pendingNextObjectives.getIfPresent(key);
                     if (obj != null) {
-                        log.info("group ADDED with key {}.. Done implementing next "
-                                + "objective: {}",
-                                appKryo.deserialize(key.key()), obj.nextObjective().id());
+                        log.info("group ADDED with key {} in dev {}.. Done implementing next "
+                                + "objective: {} <<-->> gid:{}",
+                                key, deviceId, obj.nextObjective().id(),
+                                Integer.toHexString(groupService.getGroup(deviceId, key)
+                                                    .givenGroupId()));
                         pass(obj.nextObjective());
                         pendingNextObjectives.invalidate(key);
                         flowObjectiveStore.putNextGroup(obj.nextObjective().id(), obj);
@@ -1115,30 +1472,35 @@
     }
 
     /**
-     * Represents a group-chain that implements a Next-Objective from
-     * the application. Includes information about the next objective Id, and the
-     * group keys for the groups in the group chain. The chain is expected to
-     * look like group0 --> group 1 --> outPort. Information about the groups
-     * themselves can be fetched from the Group Service using the group keys from
-     * objects instantiating this class.
+     * Represents an entire group-chain that implements a Next-Objective from
+     * the application. The objective is represented as a list of deques, where
+     * each deque can is a separate chain of groups.
+     * <p>
+     * For example, an ECMP group with 3 buckets, where each bucket points to
+     * a group chain of L3 Unicast and L2 interface groups will look like this:
+     * <ul>
+     * <li>List[0] is a Deque of GroupKeyECMP(first)-GroupKeyL3(middle)-GroupKeyL2(last)
+     * <li>List[1] is a Deque of GroupKeyECMP(first)-GroupKeyL3(middle)-GroupKeyL2(last)
+     * <li>List[2] is a Deque of GroupKeyECMP(first)-GroupKeyL3(middle)-GroupKeyL2(last)
+     * </ul>
+     * where the first element of each deque is the same, representing the
+     * top level ECMP group, while every other element represents a unique groupKey.
+     * <p>
+     * Also includes information about the next objective that
+     * resulted in this group-chain.
      *
-     * XXX Revisit this - since the forwarding objective only ever needs the
-     * groupkey of the top-level group in the group chain, why store a series
-     * of groupkeys. Also the group-chain list only works for 1-to-1 chaining,
-     * not for 1-to-many chaining.
      */
-    private class OfdpaGroupChain implements NextGroup {
+    private class OfdpaNextGroup implements NextGroup {
         private final NextObjective nextObj;
-        private final List<GroupKey> gkeys;
+        private final List<Deque<GroupKey>> gkeys;
 
-        /** expected group chain: group0 --> group1 --> port. */
-        public OfdpaGroupChain(List<GroupKey> gkeys, NextObjective nextObj) {
+        public OfdpaNextGroup(List<Deque<GroupKey>> gkeys, NextObjective nextObj) {
             this.gkeys = gkeys;
             this.nextObj = nextObj;
         }
 
         @SuppressWarnings("unused")
-        public List<GroupKey> groupKeys() {
+        public List<Deque<GroupKey>> groupKey() {
             return gkeys;
         }
 
@@ -1161,22 +1523,11 @@
      * preceding groups in the group chain to be created.
      */
     private class GroupChainElem {
-        private Collection<TrafficTreatment> bucketActions;
-        private Integer givenGroupId;
-        private GroupDescription.Type groupType;
-        private GroupKey gkey;
-        private ApplicationId appId;
+        private GroupDescription groupDescription;
         private AtomicInteger waitOnGroups;
 
-        GroupChainElem(GroupKey gkey, Integer givenGroupId,
-                       GroupDescription.Type groupType,
-                       Collection<TrafficTreatment> tr, ApplicationId appId,
-                       int waitOnGroups) {
-            this.bucketActions = tr;
-            this.givenGroupId = givenGroupId;
-            this.groupType = groupType;
-            this.gkey = gkey;
-            this.appId = appId;
+        GroupChainElem(GroupDescription groupDescription, int waitOnGroups) {
+            this.groupDescription = groupDescription;
             this.waitOnGroups = new AtomicInteger(waitOnGroups);
         }
 
@@ -1194,7 +1545,10 @@
 
         @Override
         public String toString() {
-            return Integer.toHexString(givenGroupId);
+            return (Integer.toHexString(groupDescription.givenGroupId()) +
+                    " groupKey: " + groupDescription.appCookie() +
+                    " waiting-on-groups: " + waitOnGroups.get() +
+                    " device: " + deviceId);
         }
 
     }
diff --git a/drivers/src/main/java/org/onosproject/driver/pipeline/SpringOpenTTP.java b/drivers/src/main/java/org/onosproject/driver/pipeline/SpringOpenTTP.java
index b554106..8ac5eec 100644
--- a/drivers/src/main/java/org/onosproject/driver/pipeline/SpringOpenTTP.java
+++ b/drivers/src/main/java/org/onosproject/driver/pipeline/SpringOpenTTP.java
@@ -47,6 +47,7 @@
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.flow.criteria.Criteria;
 import org.onosproject.net.flow.criteria.Criterion;
+import org.onosproject.net.flow.criteria.Criterion.Type;
 import org.onosproject.net.flow.criteria.EthCriterion;
 import org.onosproject.net.flow.criteria.EthTypeCriterion;
 import org.onosproject.net.flow.criteria.IPCriterion;
@@ -73,6 +74,7 @@
 import org.onosproject.net.group.GroupKey;
 import org.onosproject.net.group.GroupListener;
 import org.onosproject.net.group.GroupService;
+import org.onosproject.store.serializers.KryoNamespaces;
 import org.slf4j.Logger;
 
 import java.util.ArrayList;
@@ -129,8 +131,13 @@
                                     groupedThreads("onos/pipeliner",
                                                    "spring-open-%d"));
     protected KryoNamespace appKryo = new KryoNamespace.Builder()
-            .register(GroupKey.class).register(DefaultGroupKey.class)
-            .register(SegmentRoutingGroup.class).register(byte[].class).build();
+            .register(KryoNamespaces.API)
+            .register(GroupKey.class)
+            .register(DefaultGroupKey.class)
+            .register(TrafficTreatment.class)
+            .register(SpringOpenGroup.class)
+            .register(byte[].class)
+            .build();
 
     @Override
     public void init(DeviceId deviceId, PipelinerContext context) {
@@ -202,17 +209,15 @@
                     @Override
                     public void onSuccess(FlowRuleOperations ops) {
                         pass(fwd);
-                        log.debug("Provisioned tables in {} with "
-                                + "forwarding rules for segment "
-                                + "router", deviceId);
+                        log.debug("Provisioned tables in {} successfully with "
+                                + "forwarding rules", deviceId);
                     }
 
                     @Override
                     public void onError(FlowRuleOperations ops) {
                         fail(fwd, ObjectiveError.FLOWINSTALLATIONFAILED);
                         log.warn("Failed to provision tables in {} with "
-                                + "forwarding rules for segment router",
-                                deviceId);
+                                + "forwarding rules", deviceId);
                     }
                 }));
 
@@ -220,26 +225,50 @@
 
     @Override
     public void next(NextObjective nextObjective) {
-
-        log.debug("Processing NextObjective id{} op{}", nextObjective.id(),
-                  nextObjective.op());
-        if (nextObjective.op() == Objective.Operation.REMOVE) {
-            if (nextObjective.next().isEmpty()) {
-                removeGroup(nextObjective);
-            } else {
-                removeBucketFromGroup(nextObjective);
-            }
-        } else if (nextObjective.op() == Objective.Operation.ADD) {
-            NextGroup nextGroup = flowObjectiveStore.getNextGroup(nextObjective.id());
+        NextGroup nextGroup = flowObjectiveStore.getNextGroup(nextObjective.id());
+        switch (nextObjective.op()) {
+        case ADD:
             if (nextGroup != null) {
+                log.warn("Cannot add next {} that already exists in device {}",
+                         nextObjective.id(), deviceId);
+                return;
+            }
+            log.debug("Processing NextObjective id{} in dev{} - add group",
+                      nextObjective.id(), deviceId);
+            addGroup(nextObjective);
+            break;
+        case ADD_TO_EXISTING:
+            if (nextGroup != null) {
+                log.debug("Processing NextObjective id{} in dev{} - add bucket",
+                          nextObjective.id(), deviceId);
                 addBucketToGroup(nextObjective);
             } else {
-                addGroup(nextObjective);
+                log.warn("Cannot add to group that does not exist");
             }
-        } else {
+            break;
+        case REMOVE:
+            if (nextGroup == null) {
+                log.warn("Cannot remove next {} that does not exist in device {}",
+                         nextObjective.id(), deviceId);
+                return;
+            }
+            log.debug("Processing NextObjective id{}  in dev{} - remove group",
+                      nextObjective.id(), deviceId);
+            removeGroup(nextObjective);
+            break;
+        case REMOVE_FROM_EXISTING:
+            if (nextGroup == null) {
+                log.warn("Cannot remove from next {} that does not exist in device {}",
+                         nextObjective.id(), deviceId);
+                return;
+            }
+            log.debug("Processing NextObjective id{} in dev{} - remove bucket",
+                      nextObjective.id(), deviceId);
+            removeBucketFromGroup(nextObjective);
+            break;
+        default:
             log.warn("Unsupported operation {}", nextObjective.op());
         }
-
     }
 
     private void removeGroup(NextObjective nextObjective) {
@@ -256,7 +285,6 @@
         List<GroupBucket> buckets;
         switch (nextObjective.type()) {
             case SIMPLE:
-                log.debug("processing SIMPLE next objective");
                 Collection<TrafficTreatment> treatments = nextObjective.next();
                 if (treatments.size() == 1) {
                     TrafficTreatment treatment = treatments.iterator().next();
@@ -273,39 +301,57 @@
                             key,
                             null,
                             nextObjective.appId());
-                    log.debug("Creating SIMPLE group for next objective id {}",
-                              nextObjective.id());
-                    groupService.addGroup(groupDescription);
+                    log.debug("Creating SIMPLE group for next objective id {} "
+                            + "in dev:{}", nextObjective.id(), deviceId);
                     pendingGroups.put(key, nextObjective);
+                    groupService.addGroup(groupDescription);
                 }
                 break;
             case HASHED:
-                log.debug("processing HASHED next objective");
-                buckets = nextObjective
-                        .next()
-                        .stream()
-                        .map((treatment) -> DefaultGroupBucket
-                                .createSelectGroupBucket(treatment))
-                        .collect(Collectors.toList());
-                if (!buckets.isEmpty()) {
-                    final GroupKey key = new DefaultGroupKey(
-                            appKryo.serialize(nextObjective
-                                    .id()));
-                    GroupDescription groupDescription = new DefaultGroupDescription(
-                            deviceId,
-                            GroupDescription.Type.SELECT,
-                            new GroupBuckets(buckets),
-                            key,
-                            null,
-                            nextObjective.appId());
-                    log.debug("Creating HASHED group for next objective id {}",
-                              nextObjective.id());
-                    groupService.addGroup(groupDescription);
-                    pendingGroups.put(key, nextObjective);
+                // we convert MPLS ECMP groups to flow-actions for a single
+                // bucket(output port).
+                boolean mplsEcmp = false;
+                if (nextObjective.meta() != null) {
+                    for (Criterion c : nextObjective.meta().criteria()) {
+                        if (c.type() == Type.MPLS_LABEL) {
+                            mplsEcmp = true;
+                        }
+                    }
+                }
+                if (mplsEcmp) {
+                    // covert to flow-actions in a dummy group by choosing the first bucket
+                    log.debug("Converting HASHED group for next objective id {} " +
+                              "to flow-actions in device:{}", nextObjective.id(),
+                              deviceId);
+                    TrafficTreatment treatment = nextObjective.next().iterator().next();
+                    flowObjectiveStore.putNextGroup(nextObjective.id(),
+                                                    new SpringOpenGroup(null, treatment));
+                } else {
+                    // process as ECMP group
+                    buckets = nextObjective
+                            .next()
+                            .stream()
+                            .map((treatment) -> DefaultGroupBucket
+                                 .createSelectGroupBucket(treatment))
+                            .collect(Collectors.toList());
+                    if (!buckets.isEmpty()) {
+                        final GroupKey key = new DefaultGroupKey(
+                                                     appKryo.serialize(nextObjective.id()));
+                        GroupDescription groupDescription = new DefaultGroupDescription(
+                                                  deviceId,
+                                                  GroupDescription.Type.SELECT,
+                                                  new GroupBuckets(buckets),
+                                                  key,
+                                                  null,
+                                                  nextObjective.appId());
+                        log.debug("Creating HASHED group for next objective id {}"
+                                + " in dev:{}", nextObjective.id(), deviceId);
+                        pendingGroups.put(key, nextObjective);
+                        groupService.addGroup(groupDescription);
+                    }
                 }
                 break;
             case BROADCAST:
-                log.debug("processing BROADCAST next objective");
                 buckets = nextObjective
                         .next()
                         .stream()
@@ -323,10 +369,10 @@
                             key,
                             null,
                             nextObjective.appId());
-                    log.debug("Creating BROADCAST group for next objective id {}",
-                              nextObjective.id());
-                    groupService.addGroup(groupDescription);
+                    log.debug("Creating BROADCAST group for next objective id {} "
+                            + "in device {}", nextObjective.id(), deviceId);
                     pendingGroups.put(key, nextObjective);
+                    groupService.addGroup(groupDescription);
                 }
                 break;
             case FAILOVER:
@@ -417,9 +463,8 @@
     }
 
     private Collection<FlowRule> processVersatile(ForwardingObjective fwd) {
-        log.debug("Processing versatile forwarding objective");
+        log.debug("Processing versatile forwarding objective in dev:{}", deviceId);
         TrafficSelector selector = fwd.selector();
-        TrafficTreatment treatment = null;
         EthTypeCriterion ethType =
                 (EthTypeCriterion) selector.getCriterion(Criterion.Type.ETH_TYPE);
         if (ethType == null) {
@@ -428,50 +473,60 @@
             return Collections.emptySet();
         }
 
+        if (fwd.treatment() == null && fwd.nextId() == null) {
+            log.error("VERSATILE forwarding objective needs next objective ID "
+                    + "or treatment.");
+            return Collections.emptySet();
+        }
+        // emulation of ACL table (for versatile fwd objective) requires
+        // overriding any previous instructions
         TrafficTreatment.Builder treatmentBuilder = DefaultTrafficTreatment
                 .builder();
         treatmentBuilder.wipeDeferred();
 
         if (fwd.nextId() != null) {
             NextGroup next = flowObjectiveStore.getNextGroup(fwd.nextId());
-
             if (next != null) {
-                GroupKey key = appKryo.deserialize(next.data());
-
-                Group group = groupService.getGroup(deviceId, key);
-
-                if (group == null) {
-                    log.warn("The group left!");
-                    fail(fwd, ObjectiveError.GROUPMISSING);
-                    return Collections.emptySet();
+                SpringOpenGroup soGroup = appKryo.deserialize(next.data());
+                if (soGroup.dummy) {
+                    // need to convert to flow-actions
+                    for (Instruction ins : soGroup.treatment.allInstructions()) {
+                        treatmentBuilder.add(ins);
+                    }
+                } else {
+                    GroupKey key = soGroup.key;
+                    Group group = groupService.getGroup(deviceId, key);
+                    if (group == null) {
+                        log.warn("The group left!");
+                        fail(fwd, ObjectiveError.GROUPMISSING);
+                        return Collections.emptySet();
+                    }
+                    treatmentBuilder.deferred().group(group.id());
+                    log.debug("Adding OUTGROUP action");
                 }
-                treatmentBuilder.deferred().group(group.id());
-                treatment = treatmentBuilder.build();
-                log.debug("Adding OUTGROUP action");
             }
-        } else if (fwd.treatment() != null) {
+        }
+
+        if (fwd.treatment() != null) {
             if (fwd.treatment().allInstructions().size() == 1 &&
                     fwd.treatment().allInstructions().get(0).type() == Instruction.Type.OUTPUT) {
                 OutputInstruction o = (OutputInstruction) fwd.treatment().allInstructions().get(0);
                 if (o.port() == PortNumber.CONTROLLER) {
                     treatmentBuilder.punt();
-                    treatment = treatmentBuilder.build();
                 } else {
-                    treatment = fwd.treatment();
+                    treatmentBuilder.add(o);
                 }
             } else {
-                treatment = fwd.treatment();
+                for (Instruction ins : fwd.treatment().allInstructions()) {
+                    treatmentBuilder.add(ins);
+                }
             }
-        } else {
-            log.warn("VERSATILE forwarding objective needs next objective ID "
-                    + "or treatment.");
-            return Collections.emptySet();
         }
 
         FlowRule.Builder ruleBuilder = DefaultFlowRule.builder()
                 .fromApp(fwd.appId()).withPriority(fwd.priority())
                 .forDevice(deviceId).withSelector(fwd.selector())
-                .withTreatment(treatment);
+                .withTreatment(treatmentBuilder.build());
 
         if (fwd.permanent()) {
             ruleBuilder.makePermanent();
@@ -508,7 +563,8 @@
     }
 
     protected Collection<FlowRule> processSpecific(ForwardingObjective fwd) {
-        log.debug("Processing specific");
+        log.debug("Processing specific fwd objective:{} in dev:{} with next:{}",
+                  fwd.id(), deviceId, fwd.nextId());
         boolean isEthTypeObj = isSupportedEthTypeObjective(fwd);
         boolean isEthDstObj = isSupportedEthDstObjective(fwd);
 
@@ -518,7 +574,7 @@
             return processEthDstSpecificObjective(fwd);
         } else {
             log.warn("processSpecific: Unsupported "
-                    + "forwarding objective criteraia");
+                    + "forwarding objective criteria");
             fail(fwd, ObjectiveError.UNSUPPORTED);
             return Collections.emptySet();
         }
@@ -540,7 +596,8 @@
                         .getCriterion(Criterion.Type.IPV4_DST))
                         .ip());
             forTableId = ipv4UnicastTableId;
-            log.debug("processing IPv4 specific forwarding objective");
+            log.debug("processing IPv4 specific forwarding objective:{} in dev:{}",
+                      fwd.id(), deviceId);
         } else {
             filteredSelectorBuilder = filteredSelectorBuilder
                 .matchEthType(Ethernet.MPLS_UNICAST)
@@ -550,7 +607,8 @@
             //if (selector.getCriterion(Criterion.Type.MPLS_BOS) != null) {
             //}
             forTableId = mplsTableId;
-            log.debug("processing MPLS specific forwarding objective");
+            log.debug("processing MPLS specific forwarding objective:{} in dev:{}",
+                    fwd.id(), deviceId);
         }
 
         TrafficTreatment.Builder treatmentBuilder = DefaultTrafficTreatment
@@ -561,24 +619,28 @@
             }
         }
 
-        //TODO: Analyze the forwarding objective here to make
-        //device specific decision such as no ECMP groups in Dell
-        //switches.
         if (fwd.nextId() != null) {
             NextGroup next = flowObjectiveStore.getNextGroup(fwd.nextId());
-
             if (next != null) {
-                GroupKey key = appKryo.deserialize(next.data());
-
-                Group group = groupService.getGroup(deviceId, key);
-
-                if (group == null) {
-                    log.warn("The group left!");
-                    fail(fwd, ObjectiveError.GROUPMISSING);
-                    return Collections.emptySet();
+                SpringOpenGroup soGroup = appKryo.deserialize(next.data());
+                if (soGroup.dummy) {
+                    log.debug("Adding flow-actions for fwd. obj. {} "
+                            + "in dev: {}", fwd.id(), deviceId);
+                    for (Instruction ins : soGroup.treatment.allInstructions()) {
+                        treatmentBuilder.add(ins);
+                    }
+                } else {
+                    GroupKey key = soGroup.key;
+                    Group group = groupService.getGroup(deviceId, key);
+                    if (group == null) {
+                        log.warn("The group left!");
+                        fail(fwd, ObjectiveError.GROUPMISSING);
+                        return Collections.emptySet();
+                    }
+                    treatmentBuilder.deferred().group(group.id());
+                    log.debug("Adding OUTGROUP action to group:{} for fwd. obj. {} "
+                            + "in dev: {}", group.id(), fwd.id(), deviceId);
                 }
-                treatmentBuilder.deferred().group(group.id());
-                log.debug("Adding OUTGROUP action");
             } else {
                 log.warn("processSpecific: No associated next objective object");
                 fail(fwd, ObjectiveError.GROUPMISSING);
@@ -621,6 +683,12 @@
         // Do not match MacAddress for subnet broadcast entry
         if (!ethCriterion.mac().equals(MacAddress.NONE)) {
             filteredSelectorBuilder.matchEthDst(ethCriterion.mac());
+            log.debug("processing L2 forwarding objective:{} in dev:{}",
+                      fwd.id(), deviceId);
+        } else {
+            log.debug("processing L2 Broadcast forwarding objective:{} "
+                    + "in dev:{} for vlan:{}",
+                      fwd.id(), deviceId, vlanIdCriterion.vlanId());
         }
         filteredSelectorBuilder.matchVlanId(vlanIdCriterion.vlanId());
         TrafficSelector filteredSelector = filteredSelectorBuilder.build();
@@ -635,14 +703,24 @@
         if (fwd.nextId() != null) {
             NextGroup next = flowObjectiveStore.getNextGroup(fwd.nextId());
             if (next != null) {
-                GroupKey key = appKryo.deserialize(next.data());
-                Group group = groupService.getGroup(deviceId, key);
-                if (group != null) {
-                    treatmentBuilder.deferred().group(group.id());
+                SpringOpenGroup soGrp = appKryo.deserialize(next.data());
+                if (soGrp.dummy) {
+                    log.debug("Adding flow-actions for fwd. obj. {} "
+                            + "in dev: {}", fwd.id(), deviceId);
+                    for (Instruction ins : soGrp.treatment.allInstructions()) {
+                        treatmentBuilder.add(ins);
+                    }
                 } else {
-                    log.warn("Group Missing");
-                    fail(fwd, ObjectiveError.GROUPMISSING);
-                    return Collections.emptySet();
+                    GroupKey key = soGrp.key;
+                    Group group = groupService.getGroup(deviceId, key);
+                    if (group == null) {
+                        log.warn("The group left!");
+                        fail(fwd, ObjectiveError.GROUPMISSING);
+                        return Collections.emptySet();
+                    }
+                    treatmentBuilder.deferred().group(group.id());
+                    log.debug("Adding OUTGROUP action to group:{} for fwd. obj. {} "
+                            + "in dev: {}", group.id(), fwd.id(), deviceId);
                 }
             }
         }
@@ -869,14 +947,14 @@
             public void onSuccess(FlowRuleOperations ops) {
                 pass(filt);
                 log.debug("Provisioned tables in {} with fitering "
-                        + "rules for segment router", deviceId);
+                        + "rules", deviceId);
             }
 
             @Override
             public void onError(FlowRuleOperations ops) {
                 fail(filt, ObjectiveError.FLOWINSTALLATIONFAILED);
                 log.warn("Failed to provision tables in {} with "
-                        + "fitering rules for segment router", deviceId);
+                        + "fitering rules", deviceId);
             }
         }));
     }
@@ -934,15 +1012,17 @@
         @Override
         public void event(GroupEvent event) {
             if (event.type() == GroupEvent.Type.GROUP_ADDED) {
-                log.debug("InnerGroupListener: Group ADDED "
+                log.trace("InnerGroupListener: Group ADDED "
                         + "event received in device {}", deviceId);
                 GroupKey key = event.subject().appCookie();
 
                 NextObjective obj = pendingGroups.getIfPresent(key);
                 if (obj != null) {
+                    log.debug("Group verified: dev:{} gid:{} <<->> nextId:{}",
+                              deviceId, event.subject().id(), obj.id());
                     flowObjectiveStore
                             .putNextGroup(obj.id(),
-                                          new SegmentRoutingGroup(key));
+                                          new SpringOpenGroup(key, null));
                     pass(obj);
                     pendingGroups.invalidate(key);
                 }
@@ -971,21 +1051,47 @@
                                  if (obj == null) {
                                      return;
                                  }
+                                 log.debug("Group verified: dev:{} gid:{} <<->> nextId:{}",
+                                           deviceId,
+                                           groupService.getGroup(deviceId, key).id(),
+                                           obj.id());
                                  pass(obj);
                                  pendingGroups.invalidate(key);
-                                 flowObjectiveStore.putNextGroup(obj.id(),
-                                                                 new SegmentRoutingGroup(
-                                                                                         key));
-                             });
+                                 flowObjectiveStore.putNextGroup(
+                                                        obj.id(),
+                                                        new SpringOpenGroup(key, null));
+                    });
         }
     }
 
-    private class SegmentRoutingGroup implements NextGroup {
-
+    /**
+     * SpringOpenGroup can either serve as storage for a GroupKey which can be
+     * used to fetch the group from the Group Service, or it can be serve as storage
+     * for Traffic Treatments which can be used as flow actions. In the latter
+     * case, we refer to this as a dummy group.
+     *
+     */
+    private class SpringOpenGroup implements NextGroup {
+        private final boolean dummy;
         private final GroupKey key;
+        private final TrafficTreatment treatment;
 
-        public SegmentRoutingGroup(GroupKey key) {
-            this.key = key;
+        /**
+         * Storage for a GroupKey or a TrafficTreatment. One of the params
+         * to this constructor must be null.
+         * @param key represents a GroupKey
+         * @param treatment represents flow actions in a dummy group
+         */
+        public SpringOpenGroup(GroupKey key, TrafficTreatment treatment) {
+            if (key == null) {
+                this.key = new DefaultGroupKey(new byte[]{0});
+                this.treatment = treatment;
+                this.dummy = true;
+            } else {
+                this.key = key;
+                this.treatment = DefaultTrafficTreatment.builder().build();
+                this.dummy = false;
+            }
         }
 
         @SuppressWarnings("unused")
@@ -995,7 +1101,7 @@
 
         @Override
         public byte[] data() {
-            return appKryo.serialize(key);
+            return appKryo.serialize(this);
         }
 
     }