Generic Tunnel Subsystem (ONOS-1276) and L1/L0 (OTN/ROADM)extensions (ONOS-676):
1)Initial Work for ONOS-676: OTN/ROADM (L1/L0 NE) support in ONOS by extending the device/port modeling;
  - extending device type to include L1 OTN NEs;
  - extending port type to include ODUCLT port(T-port), OCH-port(L-port), OMS-port (WDM-port);
  - more standard annotations related to OTN/ROADMs support will come from PCEP provider as well as TL1 providers;
2)Intial Work for ONOS-1276: generic Tunnel subsystem in ONOS for both packet (L3/L2) networks and optical (L1/L0) networks
  - supporting PCEP framework, which is capable of interacting with the PCEP provider;
  - supporting any other kind of tunnel provider;
  - each Tunnel is associated with at least two Labels (abstracted logical entity/Id for virtualization of physical port);
  - same type of Tunnels can be formed as a reachablity graph for other services and NB applications use;

Change-Id: I29af495f90e179e2c5d8753b76e02889a3b4355b
diff --git a/core/api/src/main/java/org/onosproject/net/tunnel/TunnelProviderRegistry.java b/core/api/src/main/java/org/onosproject/net/tunnel/TunnelProviderRegistry.java
new file mode 100644
index 0000000..d6a3148
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/tunnel/TunnelProviderRegistry.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.net.tunnel;
+
+import org.onosproject.net.provider.ProviderRegistry;
+
+/**
+ * Abstraction of an tunnel provider registry.
+ */
+public interface TunnelProviderRegistry
+        extends ProviderRegistry<TunnelProvider, TunnelProviderService> {
+}