diff --git a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/Switch.java b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/Switch.java
index 7552399..95ab440 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/Switch.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/Switch.java
@@ -12,11 +12,11 @@
  *
  */
 public interface Switch {
-	public long getDpid();
+	public Long getDpid();
 
 	public Collection<Port> getPorts();
 
-	public Port getPort(short number);
+	public Port getPort(Long number);
 
 
 	// Flows
@@ -25,9 +25,10 @@
 	// Graph traversal API
 	public Iterable<Switch> getNeighbors();
 
-	public Iterable<Link> getLinks();
+	public Iterable<Link> getOutgoingLinks();
+	public Iterable<Link> getIncomingLinks();
 
-	public Link getLinkToNeighbor(long dpid);
+	public Link getLinkToNeighbor(Long dpid);
 
 	public Collection<Device> getDevices();
 }