TimoutException occurs over a network but not locally

I have a program with three WCF services and when I run them locally (i.e: Server and Clients are all on localhost) everything works. However when I test them across a network I get a TimoutException on two services but not the other. I've disabled the firewalls on all the machines involved in the test. I can both ping the server and access the wsdl "You have created a service" webpage from the client

The service that works uses a BasicHttpBinding with streaming and the two which don't work use WSDualHttpBinding. The Services that use WSDualHttpBinding both have CallbackContracts. I apologise for the vagueness of this question but I'm not really sure what code to include or where to even start looking for the solution to this.

Non-working bindings:

public static Binding CreateHTTPBinding()
{
  var binding = new WSDualHttpBinding();

  binding.MessageEncoding = WSMessageEncoding.Mtom;

  binding.MaxBufferPoolSize = 2147483647;
  binding.MaxReceivedMessageSize = 2147483647;
  binding.Security.Mode = WSDualHttpSecurityMode.None;
  return binding;
}

Exception Stack Trace:

Unhandled Exception: System.TimeoutException: The open operation did not complete within the allotted timeout of 00:01:00. The time allotted to this operation may have been a portion of a longer timeout.

Server stack trace:
   at System.ServiceModel.Channels.ReliableRequestor.ThrowTimeoutException()
   at System.ServiceModel.Channels.ReliableRequestor.Request(TimeSpan timeout)
   at System.ServiceModel.Channels.ClientReliableSession.Open(TimeSpan timeout)
   at System.ServiceModel.Channels.ClientReliableDuplexSessionChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.CallOpenOnce.System.ServiceModel.Channels.ServiceChannel.ICallOnce.Call(ServiceChannel channel, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.CallOnceManager.CallOnce(TimeSpan timeout, CallOnceManager cascade)
   at System.ServiceModel.Channels.ServiceChannel.EnsureOp开发者_JS百科ened(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]:
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at IDemeService.Register()
   at DemeServiceClient.Register()
   at DemeClient.Client.Start()
   at DemeClient.Program.Main(String[] args)

You may enable System.Net tracing on both sides and read about the Timeout exception.

http://support.microsoft.com/kb/947285

You are using a DualHttpBinding. What this means is that you are setting up a duplex channel, where server can send messages (not response message, but a incoming message) to client. But you haven't setup a clientBaseAddress where client will be listening for incoming messages from server. This is what is causing this issue. from http://msdn.microsoft.com/en-us/library/system.servicemodel.wsdualhttpbinding.aspx:

This binding requires that the client has a public URI that provides a callback endpoint for the service. This is provided by the ClientBaseAddress. A dual binding exposes the IP address of the client to the service. The client should use security to ensure that it only connects to services it trusts.