Hi Benny, while running the appliation on the emulator of S60_3rd_MR SDK in the debug mode, I found out this errors, sip_transport_ Error setting SO_RCVBUF: Invalid operation (PJ_EINVALIDOP) [70013]\n sip_transport_ Error setting SO_SNDBUF: Invalid operation (PJ_EINVALIDOP) [70013]\n I think this is the main cause of my problem stated in HELP!! Voice Connection During A SIP Call I tried to study the link you have given me but I dont know how to do that in Carbide C++ V1.3, the steps given are in PC.] Hope you can help me solve this problem as soon as possible . Thanks BR, Joseph -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20080728/329826f7/attachment.html