[ONOS-6179] Virtual Network Packet Propagation Issue

There is a problem that the packet request from virtual network
is not relay to real packet service because
VirtualNetworkPacketService cannot process requestPacket()
properly.
Moreover, the installed flow rules from vNet are not syncronized
with the physical rules.

Change-Id: I20c3e1fbb7668f563fafcb3a9d6a7d80ffba55fd
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/provider/VirtualPacketProvider.java b/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/provider/VirtualPacketProvider.java
index 11c2b00..abd1d7d 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/provider/VirtualPacketProvider.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/provider/VirtualPacketProvider.java
@@ -21,10 +21,9 @@
 /**
  * Abstraction of a virtual packet provider capable of emitting packets
  * from virtual network core services to the underlay network.
- * This provider de-virtualzes OutboundPacket, and virtualizes PacketContext.
+ * This provider de-virtualizes and virtualize PacketContext.
  */
 public interface VirtualPacketProvider extends VirtualProvider {
-
     /**
      * Emits the specified outbound packet onto the underlay physical network.
      * This provider maps the requested packets for physical network.
@@ -36,7 +35,15 @@
 
     /**
      * Starts to deliver packets to virtual packet managers.
+     *
+     * @param networkId the network identifier
      */
-    void startPacketHandling();
+    void startPacketHandling(NetworkId networkId);
 
+    /**
+     * Stops to deliver packets to virtual packet managers.
+     *
+     * @param networkId the network identifier
+     */
+    void stopPacketHandling(NetworkId networkId);
 }