yeah old post. but, for you and me probably the most important thing is, pjsip will eventually replace chan_sip... and the makers consider pjsip supreme to chan_sip - as long as it does what it is supposed to... In Other Words: there shouldn't be any difference to end users; but it makes life better for the coders. In which case, we end users (of tools like FreePBX) should not know any difference. If that makes sense