Echo, unless you’re in a karaoke pub, is very annoying.
Over the years we have added support for various echo suppression and cancellation algorithm and libraries, like Speex and bdIMAD.
WebRTC, besides being a communications protocol on its own right, contains a powerful media component which in turn contains, among other things, acoustic echo cancellation algorithm implementation.
Try pjsip using WebRTC AEC on the development code by following the usage notes.
Eventually this will form part of 2.5 release (before you ask, no, we don’t have a definite timeframe for it).
Originally posted on http://blog.pjsip.org