Hey Nanang, Thanks for your reply. The was the case exactly, the two devices were affecting each other. I disabled the echo suppression, and I guess the half duplex thing is not around anymore. However, I still have certain delay.. I guess this is due to the jitter buffer settings. Thanks, -- a. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20080522/83493b24/attachment.html