Hi,benny I'm using pjsip-0.8.0 and vs2003, call pjsip from GUI (MFC dialog) without creating any other thread. issue is : 1.register is successful; 2.but when call place a call,will appear "Calling pjlib from unknown/external thread. You must register external threads with pj_thread_register() before calling any pjlib functions."; 3.others,if use breakpoint during the dial process, it's ok; and the same call flow in pjsip 0.5.10 is ok too. question is: This issue causes by not using pj_thread_register(), but register is successful, or other reason, give me some advise. thanks! -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20071217/835a4dc0/attachment.html