diff --git a/jingle/extension/source/org/jivesoftware/smackx/jingle/nat/ICEResolver.java b/jingle/extension/source/org/jivesoftware/smackx/jingle/nat/ICEResolver.java
index a8317cf00..6df185e26 100644
--- a/jingle/extension/source/org/jivesoftware/smackx/jingle/nat/ICEResolver.java
+++ b/jingle/extension/source/org/jivesoftware/smackx/jingle/nat/ICEResolver.java
@@ -27,6 +27,7 @@ import org.jivesoftware.smack.XMPPException;
 import org.jivesoftware.smack.XMPPConnection;
 
 import java.net.UnknownHostException;
+import java.net.SocketException;
 import java.util.List;
 import java.util.Random;
 
@@ -80,6 +81,12 @@ public class ICEResolver extends TransportResolver {
                     transportCandidate.setLocalIp(candidate.getBase().getAddress().getInetAddress().getHostAddress());
                     transportCandidate.setPort(getFreePort());
                     this.addCandidate(transportCandidate);
+                    try {
+                        transportCandidate.addCandidateEcho();
+                    }
+                    catch (SocketException e) {
+                        e.printStackTrace();
+                    }
                     System.out.println("C: " + candidate.getAddress().getInetAddress() + "|" + candidate.getBase().getAddress().getInetAddress() + " p:" + candidate.getPriority());
 
                 }
diff --git a/jingle/extension/source/org/jivesoftware/smackx/jingle/nat/TransportNegotiator.java b/jingle/extension/source/org/jivesoftware/smackx/jingle/nat/TransportNegotiator.java
index 6ed63e73e..9b42adac2 100644
--- a/jingle/extension/source/org/jivesoftware/smackx/jingle/nat/TransportNegotiator.java
+++ b/jingle/extension/source/org/jivesoftware/smackx/jingle/nat/TransportNegotiator.java
@@ -41,13 +41,13 @@ public abstract class TransportNegotiator extends JingleNegotiator {
     private final TransportResolver resolver;
 
     // Transport candidates we have offered
-    private final List offeredCandidates = new ArrayList();
+    private final List<TransportCandidate> offeredCandidates = new ArrayList<TransportCandidate>();
 
     // List of remote transport candidates
-    private final List remoteCandidates = new ArrayList();
+    private final List<TransportCandidate> remoteCandidates = new ArrayList<TransportCandidate>();
 
     // Valid remote candidates
-    private final List validRemoteCandidates = new ArrayList();
+    private final List<TransportCandidate> validRemoteCandidates = new ArrayList<TransportCandidate>();
 
     // The best local candidate we have offered (and accepted by the other part)
     private TransportCandidate acceptedLocalCandidate;
@@ -103,7 +103,7 @@ public abstract class TransportNegotiator extends JingleNegotiator {
      *
      * @return true if the transport candidate is acceptable
      */
-    public abstract boolean acceptableTransportCandidate(TransportCandidate tc);
+    public abstract boolean acceptableTransportCandidate(TransportCandidate tc, List<TransportCandidate> localCandidates);
 
     /**
      * Obtain the best local candidate we want to offer.
@@ -167,7 +167,7 @@ public abstract class TransportNegotiator extends JingleNegotiator {
     private void addRemoteCandidate(TransportCandidate rc) {
         // Add the candidate to the list
         if (rc != null) {
-            if (acceptableTransportCandidate(rc)) {
+            if (acceptableTransportCandidate(rc, offeredCandidates)) {
                 synchronized (remoteCandidates) {
                     remoteCandidates.add(rc);
                 }
@@ -773,7 +773,7 @@ public abstract class TransportNegotiator extends JingleNegotiator {
         /**
          * Return true for fixed candidates.
          */
-        public boolean acceptableTransportCandidate(TransportCandidate tc) {
+        public boolean acceptableTransportCandidate(TransportCandidate tc, List<TransportCandidate> localCandidates) {
             return tc instanceof TransportCandidate.Fixed;
         }
     }
@@ -834,18 +834,24 @@ public abstract class TransportNegotiator extends JingleNegotiator {
         /**
          * Return true for ICE candidates.
          */
-        public boolean acceptableTransportCandidate(TransportCandidate tc) {
+        public boolean acceptableTransportCandidate(TransportCandidate tc, List<TransportCandidate> localCandidates) {
             try {
                 TransportCandidate.Ice ice = (TransportCandidate.Ice) tc;
                 if (ice.getType().equals("relay")) return true;
+
+                for (TransportCandidate candidate : localCandidates) {
+                    TransportCandidate.CandidateEcho echo = candidate.getCandidateEcho();
+                    if (echo != null) {
+                        if (echo.test(InetAddress.getByName(ice.getId()), ice.getPort(), 300))
+                            return true;
+                    }
+                }
+
                 InetAddress.getByName(tc.getIp()).isReachable(3000);
                 DatagramSocket socket = new DatagramSocket(0);
                 socket.connect(InetAddress.getByName(tc.getIp()), tc.getPort());
                 return true;
             }
-            catch (SocketException e) {
-                e.printStackTrace();
-            }
             catch (UnknownHostException e) {
                 e.printStackTrace();
             }