Hi, When I'm using late negotiation and in my dialplan do the following: <action application="export" data="codec_string=${ep_codec_string}"/> <action application="set" data="inherit_codec=true"/> (I also tried with absolute_codec_string instead of codec_string) Then the codecs (or more precisely said, the rtpmap lines) that are offered in the SDP of the A leg are not offered to the b-leg. Only the RTP payload numbers as defined by IANA are there in the media (m) header. For example: a-leg SDP in INVITE: m=audio 16864 RTP/AVP 18 101. a=rtpmap:18 G729/8000. a=rtpmap:101 telephone-event/8000. b-leg SDP in INVITE: m=audio 24148 RTP/AVP 18 101 13. a=rtpmap:101 telephone-event/8000. Is there a reason why FS removes the G729 rtpmap, even though I exported all into the codec_string chan var ? Now, this would normally be fine because G729 being 18 is a static rtpmap, but I have one endpoint that has the behavior that if I send an invite with RTP payload 18 and omit the rtpmap being G729, then it responds with a 183 session progress containing rtpmap G.729 (notice the dot) - this is wrong as far as I can tell. Apparently they respond with the correct G729 (without the dot) in their 183 sess progress if I include the rtpmap in my invite. I believe I read somewhere there was an option settable (on a sip profile?) that enables to always send all payloads as defined in the media (m) sdp header as a=rtpmap lines, but I cannot find the option anymore (or perhaps I'm mistaken and saw it somewhere else ?) Can someone help me with this ? Thanks & kind regards, Leon