diff --git a/core/api/src/main/java/org/onlab/onos/net/Link.java b/core/api/src/main/java/org/onlab/onos/net/Link.java
index 1ae5b9d..3e23dc1 100644
--- a/core/api/src/main/java/org/onlab/onos/net/Link.java
+++ b/core/api/src/main/java/org/onlab/onos/net/Link.java
@@ -25,7 +25,18 @@
         /**
          * Signifies that this link is an edge, i.e. host link.
          */
-        EDGE
+        EDGE,
+
+        /**
+         * Signifies that this link represents a logical link backed by
+         * some form of a tunnel.
+         */
+        TUNNEL,
+
+        /**
+         * Signifies that this link is realized by optical connection.
+         */
+        OPTICAL
     }
 
     /**
@@ -49,6 +60,4 @@
      */
     Type type();
 
-    // LinkInfo info(); // Additional link information / decorations
-
 }