lldp discovery independent of OF

Change-Id: I720f727f6628e30e5d732e6d7bf742d1b7050812
diff --git a/core/api/src/main/java/org/onlab/onos/net/device/DeviceDescription.java b/core/api/src/main/java/org/onlab/onos/net/device/DeviceDescription.java
index e32c19d..99b49ab 100644
--- a/core/api/src/main/java/org/onlab/onos/net/device/DeviceDescription.java
+++ b/core/api/src/main/java/org/onlab/onos/net/device/DeviceDescription.java
@@ -2,6 +2,7 @@
 
 import org.onlab.onos.net.Description;
 import org.onlab.onos.net.Device;
+import org.onlab.packet.ChassisId;
 
 import java.net.URI;
 
@@ -54,4 +55,11 @@
      */
     String serialNumber();
 
+    /**
+     * Returns a device chassis id.
+     *
+     * @return chassis id
+     */
+    ChassisId chassisId();
+
 }