On 2013-01-24 11:15 AM, Dede wrote: > Hello all, > I read docs and I can see that there's echo cancellation support in PJSUA. > It seems also that on Mac OS, CoreAudio should do the trick. i think that you need to patch your sources to use the CoreAudio backend. if i remember correctly, the portaudio backend is used by default on mac osx builds. (see message by samuel vinson in the archives -- http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/2012-September/015216.html) cheers, - j