UCMA 3.0: UserEndPoint BeginEstablish exception: Microsoft.Rtc.Signaling.ConnectionFailureException

Hello,

  I'm using UCMA 3.0 to write a web service that creates a userEndpoint and attempts to register it via BeginEstablish().  Before this gets called, a CollaborationPlatform object is created and started, successfully.  But when I try to establish the userEndpoint, I get the following error:

Endpoint  failed to establish: Microsoft.Rtc.Signaling.ConnectionFailureException:Unable to establish a connection. ---> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 172.30.228.57:5061

   at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult)
   at Microsoft.Rtc.Internal.Sip.TcpTransport.OnConnected(Object arg)
   
--- End of inner exception stack trace ---
   at Microsoft.Rtc.Signaling.SipAsyncResult`1.ThrowIfFailed()
   at Microsoft.Rtc.Signaling.Helper.EndAsyncOperation[T](Object owner, IAsyncResult result)
   at Microsoft.Rtc.Collaboration.LocalEndpoint.EndEstablish(IAsyncResult result)
   at appIcLync.IcLyncMgr.EndEndpointEstablish(IAsyncResult ar) in C:\Users\administrator\Documents\Visual Studio 2010\Projects\appIcLync\appIcLync\IcLyncMgr.cs:line 187
Detected at System.Environment.get_StackTrace()
   at Microsoft.Rtc.Signaling.ConnectionFailureException..ctor(String message, Exception innerException)
   at Microsoft.Rtc.Signaling.ExceptionUtilities.TryMapS4Exception(Exception s4Exception, SecurityAssociationContext securityContext, Boolean isSipEndpoint, String traceId, Object parentObject, Object childObject, RealTimeException& ex)
   at Microsoft.Rtc.Signaling.SipTransactionAsyncResult`1.ConnectionConnectCompleted(IAsyncResult result)
   at Microsoft.Rtc.Signaling.SipAsyncResult2`1.MakeCallback()
   at Microsoft.Rtc.Signaling.SipAsyncResult2`1.Complete(TEx ex, Boolean synchronousCompletion)
   at Microsoft.Rtc.Signaling.SipAsyncResult2`1.Complete(TEx ex)
   at Microsoft.Rtc.Signaling.RealTimeConnection.CompletePendingConnects(IEnumerable`1 results, RealTimeException exception)
   at Microsoft.Rtc.Signaling.RealTimeConnection.<.ctor>b__0(SipConnection sender, Object reason)
   at Microsoft.Rtc.Internal.Sip.SipConnection.DisconnectedEventHandler.Invoke(SipConnection sender, Object reason)
   at Microsoft.Rtc.Internal.Sip.SipConnection.FireDisconnectedEvent(Object reason)
   at Microsoft.Rtc.Internal.Sip.SingleThreadedDispatcherQueue.DispatcherCallback(Object queue)
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal(_ThreadPoolWaitCallback tpWaitCallBack)
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(Object state)