Hi Geeks, When I join a call to echo application with H264 as video codec there is no video sent back from FreeSWITCH while with VP8 it sends video. I am using Linphone on iPhone 6 as SIP client I am using FreeSWITCH Version 1.8.4+git~20181227T011058Z~749a6e108b~64bit (git 749a6e1 2018-12-27 01:10:58Z 64bit) on Debian Release 9.6 stretch. mod_h26x is enabled and and it show it loaded, freeswitch@Dev-Togee-media-fra-16> module_exists mod_h26x true it enabled as only video codec in var.xml, <X-PRE-PROCESS cmd="set" data="global_codec_prefs=OPUS,PCMU,PCMA,H264"/> <X-PRE-PROCESS cmd="set" data="outbound_codec_prefs=OPUS,PCMU,PCMA,H264"/> Linphone client send H264 in SDP offer, v=0 o=USR1001 3576 2398 IN IP4 10.0.0.106 s=Talk c=IN IP4 10.0.0.106 t=0 0 a=rtcp-xr:rcvr-rtt=all:10000 stat-summary=loss,dup,jitt,TTL voip-metrics m=audio 7212 RTP/AVP 96 0 8 101 97 a=rtpmap:96 opus/48000/2 a=fmtp:96 useinbandfec=1 a=rtpmap:101 telephone-event/48000 a=rtpmap:97 telephone-event/8000 a=rtcp-fb:* trr-int 1000 a=rtcp-fb:* ccm tmmbr m=video 9236 RTP/AVP 96 a=rtpmap:96 H264/90000 a=fmtp:96 profile-level-id=42801F a=rtcp-fb:* trr-int 1000 a=rtcp-fb:* ccm tmmbr a=rtcp-fb:96 nack pli a=rtcp-fb:96 ccm fir but FreeSWITCH replies SDP without video , v=0 o=FreeSWITCH 1554713996 1554713997 IN IP4 178.33.144.18 s=FreeSWITCH c=IN IP4 178.33.144.18 t=0 0 m=audio 754 RTP/AVP 96 101 a=rtpmap:96 opus/48000/2 a=fmtp:96 useinbandfec=1 a=rtpmap:101 telephone-event/48000 a=fmtp:101 0-16 a=ptime:20 m=video 0 RTP/AVP 19 It is really strange behavior, I really appreciate any suggestion and help on it. Regards, Faisal