Hi, There's a FAQ page of pjsip at http://www.pjsip.org/trac/wiki/FAQ. Which version of pjsip is it based on? I have the same problem as described by http://www.pjsip.org/trac/wiki/FAQ#tx-timing. Trying to do what it suggests actually seems to worsen the problem. I am working on version 0.7.0 (updated till rev1534). Thanks, Anshuman