I am running Call mgr V6 and support a facility with 600 ipt phones in Beijing China. I experience problem on external call, call to call mgr exten (this extension set up forwarded to to an external number. In ISDN trace, Call mgr sends the did prefix i.e. 6789 and external calling party's last 4 digit of the calling phone, it makes the number becomes an unregistered number on this particular pri line, The PTT rejects the call, did not complete the call and hung in the pri network. The forward function works if call is an internal ext, call mgr forward the call to an external extn (call mgr sends out the caller correct prfix and ext) as well as the caller calls from a phone last 4 digit coincide with the registered number in the pri network. other facility to other PTT in, the Call manager sends out the same pattern number, the PTT acknowledges the call (unregistered number), sends the call to the final destination with customer's registered prime number. I dont know why BJ PTT does not provide similar service. In call manager or pri h323 router configuration,can we have a workaround (forarded a registered did number on forwarded call) and retain original caller id for normal ddn call from call manager. Need some guidance.