Dear AR, You should not repost a previous post. If no one answers, either nobody knows the answer or your post was not precise enough to enable people to answer. It was very rare that a well-explained problem goes unanswered on serusers. Personally, I don't have a clue what you are talking about. You obviously have lookup("aliases") in your ser.cfg. What is an "NB"? And why should there be any difference between your PC and other PCs? Do your homework first: Describe your setup, analyze what is happening through logs and SIP traces and describe under which circumstances the alias lookup works and fails. Then, maybe someone can help you out. g-) AR. wrote: