[SR-Users] WebRTC proxy with rtpengine - How to change from RTP to SRTP on 488 response

Hi, I have implemented a WebRTC proxy using Kamailio and rtpengine, in front of Asterisk servers. I have an issue where I do not know in advance whether the Asterisk client is set to use RTP or SRTP. My implementation expects the web side to be SRTP and the Asterisk side plain RTP. However, if the asterisk side requires SRTP I receive a 488 Not Acceptable here. The same is true when an SRTP client from the Asterisk side dials out to the webrtc client, I need to catch whether the request is SRTP or RTP and generate rtpengine offer accordingly. This was discussed in github, with a description of a solution here: https://github.com/sipwise/rtpengine/issues/435#issuecomment-391937398 <https://github.com/sipwise/rtpengine/issues/435#issuecomment-391937398>- however I am unsure how to implement this. Does anyone have an example of how I can change the rtpengine SDP in such a case? Thanks -- -Barry