Routing problem

I could finally make the Sip trunk work in both direction between my Asterisk box and Cisco call manager 4.1.

I can call all internal extension of both system from both systems but i can’t call from Asterisk to an external pstn number through Call manager using call manager pstn gateway. I receive busy voice message.

From call manager i can call on pstn but when it receives a call from the trunk it seems not able to route it.

Any hint?