Hello, If an incoming INVITE message contains an SDP-body, but no "m=" lines, how will pjsip react? I just tried it, and got a "400 Missing media in SDP" reply. Is there any way to configure pjsip such that zero media descriptions are allowed? The idea is to first establish a session, and add media later with a re-INVITE. Is such a scenario possible with pjsip? Thanks and regards, Georg