On 04/11/2018 09:28 AM, George Diamantopoulos wrote:
Hello all,
I have the following issue (I think) with RTP engine. An INVITE comes in, and rtpengine will rewrite the SDP accordingly, as configured in kamailio.cfg. After some time a reINVITE is sent out in the opposite direction, for session refresh purposes. As I use rtcp-mux-offer in kamailio.cfg for this direction, RTPengine will inject the rtcp-mux parameter, and this reINVITE is forwarded to the UAC that sent the original INVITE.
However, the SDP in the reINVITE is exactly the same as the SDP in the 200 OK to the original INVITE, with the exception of the rtcp-mux parameter. Since the SDP offered from the same end has changed, shouldn't session version be incremented as well?
Does this sound like something that should be reported as a bug to rtpengine? Or am I missing something here?
Technically of course you're correct in that the version counter should be incremented if the SDP changed. Currently rtpengine always leaves the o= line unchanged, so there can be a discrepancy here in certain cases. This should probably be fixed, but this is also the first time I've heard of this actually causing an issue.
Cheers