Hi All, here is our simple architecture <client A>---<FreeSWITCH> <client B>----/ - client A and B are both registered on FreeSWITCH via websocket (using sipjs 0.9.2) - we enable video-mode= transcode and load mod_av on FreeSWITCH. - if client A uses chrome on PC and client B use safari on *MAC*, they can see each other, talk to each other in the same conference. - if client A uses chrome on PC and client B use safari on *iPhone*(8plus, iOS 11.4), they can NOT see each other, talk to each other in the same conference. I though safari on MAC works, then safari on iPhone should work, but not. Is it possible to fix that with changing configuration of FreeSWITCH? or any suggestion? Thanks in advance. FreeSWITCH Version 1.6.20 Ubuntu Server Ubuntu 14.04.1 LTS 64bit libav-11.4 or libav-12 See below configurations: 1. enable video-mode= transcode <param name="conference-flags" value="transcode-video|minimize-video-encoding"/> <param name="video-mode" value="transcode"/> 2.enable VP8/H264 codec support <X-PRE-PROCESS cmd="set" data="global_codec_prefs=PCMU,PCMA,VP8,H264"/> <X-PRE-PROCESS cmd="set" data="outbound_codec_prefs=PCMU,PCMA,VP8,H264"/> 3.enable mod_av and disable mod_h26x <load module="mod_av"/> <!--<load module="mod_h26x"/>-->