[WIP] CORD-129 Support access agent in VTN

- Add ACCESS_AGENT type instance based on the access agent location
- Populate flow rules to provider L2 connectivity with OLTs
- Don't check "tap" port name prefix considering container instance
- Changed table name ACCESS_TYPE to ACCESS, DST_IP to DST

Change-Id: Ibcf7ea97cd5e16e15d6deff1c8579a83ac9e13f8
diff --git a/src/main/java/org/opencord/cordvtn/api/Constants.java b/src/main/java/org/opencord/cordvtn/api/Constants.java
index bee5734..9fd3b2c 100644
--- a/src/main/java/org/opencord/cordvtn/api/Constants.java
+++ b/src/main/java/org/opencord/cordvtn/api/Constants.java
@@ -15,6 +15,7 @@
  */
 package org.opencord.cordvtn.api;
 
+import org.onlab.packet.Ip4Address;
 import org.onlab.packet.TpPort;
 
 /**
@@ -34,8 +35,10 @@
 
     public static final String DEFAULT_TUNNEL = "vxlan";
     public static final String INTEGRATION_BRIDGE = "br-int";
-    public static final String VPORT_PREFIX = "tap";
+    public static final String NOT_APPLICABLE = "N/A";
 
     public static final int OF_PORT = 6653;
     public static final TpPort OVSDB_PORT = TpPort.tpPort(6640);
+    public static final Ip4Address DEFAULT_DNS = Ip4Address.valueOf("8.8.8.8");
+    public static final int DHCP_INFINITE_LEASE = -1;
 }