Fowarding calls are making double calls and one way audio

[bduke08021]

So i have my ext forwarding my calls to external ext when the internal device is not registered. The call goes through to my cell phone, when i accept the call, i have no audio and a second call comes into my cell phone from the pbx, i accept that call i can only hear the caller, they can not hear me.

Using version 8 on windows server 2003
Callcentric is the voip provider

 

[leejor]

Someone else was having a similar problem a while back, the double calls part. Can't find the thread offhand.
As a guess, I would say that some of the SIP messages are being lost (blocked ports?) . This might cause the one way audio if the port info as to which port(s) to use can't get through. If this happens every time I would suggest posting the 3CX sever log from the incoming call to the point where you answer your mobile the second time. Does the same thing happen if the call is forwarded to a landline? What about forwarded on a route other than Callcentric (if available)?