Thanks for reply,the default SIP port is 5060,but in my project,SIP server was developered by other team,so i must use port 5088. Just now ,I modified sip_transport.c,replaced PJSIP_TRANSPORT_UDP, 5060, {"UDP", 3}, wihs PJSIP_TRANSPORT_UDP, 5088, {"UDP", 3}, it seems PUBLISH is ok,is this way correct? Regards 2009-09-25 mylen I think SIP uses 5060 port by default. Maybe you could try changing the bind or listen port for the PBX your using. If your using asterisk you can set bindport in sip.conf. Rachel -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20090925/00af4ba6/attachment.html> -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 1237 bytes Desc: not available URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20090925/00af4ba6/attachment.gif>