Remote Extension won't make external calls

Hi all,
I have now got my remote extension working approx. 80%.
I can make and recieve internal calls and I can recieve external calls.
The only issue is I cannot make external calls. All other extension work OK (they are not remote). If i check the web interface I can see the activity from the internal calls etc. but when making an external call from the remote location there is no activity.
ports forwarded to trixbox. udp 5060 and udp 10001 - 20000
as stated phone is registered OK and will receive both internal and external calls but will only make internal calls.
I forwarded udp 5060 on the remote side to the phone. I dont think this does anything but I could be wrong.
Any help / ideas would be appreciated.