[Spce-user] Command “RTP” converts SAVPF to AVP — F is missing in the destination

[Дилян Палаузов]

Hello,

kamailio/rtpengine receives SDP containing:

m=audio 28782 UDP/TLS/RTP/SAVPF 111 63 9 0 8 13 110 126

In order to remove the security, I call in Kamailio

KSR.rtpengine.rtpengine_manage("replace-session-connection replace-origin SDES-pad SIP-source-address RTP")

The outgoing SDP contains:

m=audio 39954 RTP/AVP 111 63 9 0 8 13 110 126


Considering that the code says nothing about AVP my expectation is that SAVPF is converted to AVPF and the system sends RTP/AVPF.  That is, I expect
as output

m=audio 39954 RTP/AVPF 111 63 9 0 8 13 110 126

My expectation is based also on my reading of https://kamailio.org/docs/modules/devel/modules/rtpengine.html :

> RTP, SRTP, DTLS, AVP, AVPF - These flags control the RTP transport protocol that should be used towards the recipient of the SDP. If none of them
are specified, the protocol given in the SDP is left untouched. Otherwise, the “SRTP” flag indicates that SRTP should be used, while “RTP” indicates
that SRTP should not be used. “AVPF” indicates that the advanced RTCP profile with feedback messages should be used, and “AVP” indicates that the
regular RTCP profile should be used. See also the next set of flags below. 

“should be used” does not mean that any rewritings will be done.

I use nearly the lastest version of rtpengine on git.

I want only to strip the encryption, in order to do test calls to http://enum-test.at/index.html ⇔ sip.nemox.net, keeping the “feedback” if it was
present.  The latter does not support encryption.

Greetings
  Дилян