Add key constants for ODTN

Change-Id: I21cefc09835e3f1d8c393e470889af9ba86d50cd
diff --git a/apps/odtn/api/src/main/java/org/onosproject/odtn/behaviour/OdtnDeviceDescriptionDiscovery.java b/apps/odtn/api/src/main/java/org/onosproject/odtn/behaviour/OdtnDeviceDescriptionDiscovery.java
index e8657ea..6e5bc81 100644
--- a/apps/odtn/api/src/main/java/org/onosproject/odtn/behaviour/OdtnDeviceDescriptionDiscovery.java
+++ b/apps/odtn/api/src/main/java/org/onosproject/odtn/behaviour/OdtnDeviceDescriptionDiscovery.java
@@ -20,24 +20,42 @@
 import org.onosproject.net.device.DeviceDescriptionDiscovery;
 import org.onosproject.net.device.PortDescription;
 
+import com.google.common.annotations.Beta;
+
 /**
  * DeviceDescriptionDiscovery used in ODTN.
  *
  * Just declaring certain Annotations will be required.
  */
+@Beta
 public interface OdtnDeviceDescriptionDiscovery
         extends DeviceDescriptionDiscovery {
 
     /**
-     * Annotations key, which stores OpenConfig component name.
+     * Annotations key intended for a Port, which stores OpenConfig component name.
      */
     String OC_NAME = "oc-name";
 
     /**
-     * Annotations key, which stores OpenConfig component type.
+     * Annotations key intended for a Port, which stores OpenConfig component type.
      */
     String OC_TYPE = "oc-type";
 
+    // will also be used from TAPI model to point to what we want to configure
+    /**
+     * Annotations key intended for a Port,
+     * which stores string identifier used to
+     * logically group Ports corresponding to a transponder.
+     */
+    String TRANSPONDER_NAME = "odtn-transponder-name";
+
+
+    /**
+     * OpenConfig component property name to store,
+     * decimal integer index to be used when creating PortNumber.
+     */
+    String ONOS_PORT_INDEX = "onos-index";
+
     // overriding just to make checkstyle happy
     @Override
     List<PortDescription> discoverPortDetails();
diff --git a/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/OpenConfigDeviceDiscovery.java b/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/OpenConfigDeviceDiscovery.java
index 54e2601..5bd7345 100644
--- a/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/OpenConfigDeviceDiscovery.java
+++ b/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/OpenConfigDeviceDiscovery.java
@@ -170,14 +170,14 @@
             props.put(pName, pValue);
         });
 
-        if (!props.containsKey("onos-index")) {
+        if (!props.containsKey(ONOS_PORT_INDEX)) {
             log.info("DEBUG: Component {} does not include onos-index, skipping", name);
             // ODTN: port must have onos-index property
             return null;
         }
 
         Builder builder = DefaultPortDescription.builder();
-        builder.withPortNumber(PortNumber.portNumber(Long.parseLong(props.get("onos-index")), name));
+        builder.withPortNumber(PortNumber.portNumber(Long.parseLong(props.get(ONOS_PORT_INDEX)), name));
 
         switch (type) {
         case "oc-platform-types:PORT":