Strange, i start many transports in the same application. But i use an UDP transports, not TCP. May be in the fourth param you don't use 1, instead this use the count of your transports? ** @param async_cnt Number of simultaneous asynchronous accept() * operations to be supported. It is recommended that * the number here corresponds to the number of * processors in the system (or the number of SIP * worker threads).* And the last parameter must be different instances of the tcp transport if you want to start different transports :) Regards -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20090519/248ee884/attachment-0001.html>