Hi, Can I know the Call ID of a UAC / UAS who has been registered on th eproxy server? I need to send the MESSAGE to the Particular "UAC" but I do not know the Call ID ? There is no INVITE nor Call Established.But I need to send IM to that particular UAC. As Far As I Know, Call id is mandatory , Hence I need to know the Call id from the prosy server. How should I proceed? Thanks and Regards. Abhijit