[GEANT] Command device-interfaces added.

Change-Id: If70eedc5e8e0d83bc4d31c556fbf8382cbe97cec
diff --git a/core/api/src/main/java/org/onosproject/net/device/DeviceInterfaceDescription.java b/core/api/src/main/java/org/onosproject/net/device/DeviceInterfaceDescription.java
new file mode 100644
index 0000000..6b14c37
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/device/DeviceInterfaceDescription.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2016-present 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.device;
+
+import org.onlab.packet.VlanId;
+
+import java.util.List;
+
+/**
+ * The description of an interface used for legacy devices.
+ */
+public interface DeviceInterfaceDescription {
+    /**
+     * Represents the type of operation of the interface.
+     */
+    enum Mode {
+        /**
+         * Normal mode of interface operation.
+         */
+        NORMAL,
+        /**
+         * Access mode to a VLAN for interface.
+         */
+        ACCESS,
+        /**
+         * Trunk mode for a set of VLANs for interface.
+         */
+        TRUNK
+    }
+
+    /**
+     * Returns the name of the interface.
+     *
+     * @return name of the interface
+     */
+    String name();
+
+    /**
+     *  Returns the operation mode of the interface.
+     *
+     *  @return operation mode of the interface
+     */
+    Mode mode();
+
+    /**
+     *  Returns the VLAN-IDs configured for the interface. No VLAN-ID should be
+     *  returned for NORMAL mode, 1 VLAN-ID for access mode and 1 or more
+     *  VLAN-IDs for trunking mode.
+     *
+     *  @return VLAN-ID(s) configured for the interface.
+     */
+    List<VlanId> vlans();
+
+    /**
+     *  Indicates whether a rate limit has been set on the interface.
+     *
+     *  @return indication whether interface is rate limited or not
+     */
+    boolean isRateLimited();
+
+    /**
+     *  Returns the rate limit set on the interface bandwidth.
+     *
+     *  @return the rate limit set on the interface bandwidth
+     */
+    short rateLimit();
+}