Change WCF service/client settings to make it works correctly

I have working WCF tcp duplex service and client. Everything works fine but at some point on the client I'm getting an exception: "[login to view URL]: This request operation sent to [login to view URL]://.../Broadcastor/ did not receive a reply within the configured timeout (00:00:08)." The thing is that on the server I can see that the client request was finished within 1 second an there were no timeout, so problem is on the client side. May be there is problem with SynchronizationContext on the client side. Just in case this is what I have: [ServiceBehavior(InstanceContextMode = [login to view URL], ConcurrencyMode = [login to view URL], UseSynchronizationContext = false)] [CallbackBehavior(ConcurrencyMode = [login to view URL], UseSynchronizationContext = false)] If someone had similar experience or just know how to fix it let me know.