nanang, i fixed the port and type. thanks a lot for the information,it could be the problem, i will check it. is contact header must need 'transport=tls' for response message ? thanks towhid Please check contact header of remote peer, just in case it didn't contain URI param 'transport=tls'. BR, nanang -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20091028/c3a25ced/attachment.html>