Support for RFC5168 in Asterisk13


#1

Hi all ,
Could you please update me with the following information:

  • Does Asterisk 13 with PJSIP channel driver support video update functionality by means of SIP INFO in accordance with RFC5168 specification?

  • Is any special configuration to enable it needed (if “yes”, what exactly should be configured)?

I have encountered this question in various forums but has met no clear answer.
Thank you in advance.


#2

Please don’t directly tag me. As with everything on here if I feel I have any value to add I will respond. The chan_pjsip module supports sending it[1]. It does not currently support receiving it, and instead expects it to occur within RTCP. If VP8 or VP9 is in use then INFO is not used and it is sent in RTCP.

[1] https://github.com/asterisk/asterisk/blob/master/channels/chan_pjsip.c#L1310


#3

Does this mean that the calling party (for example) should send video updates in RTCP whereas the called party will receive these updates from Asterisk in SIP INFO?
Does Asterisk support sending video updates in RTCP (instead of SIP INFO) in H.263 and H.264 codecs as well?
Are any other viable options to exchange keyframes between endpoints via Asterisk with PJSIP and H.263 / H.264 codecs?
Thanks.


#4
  1. Yes
  2. No
  3. Key frames can be exchanged at a regular interval in the video stream itself. The RTCP or INFO method is used to request one explicitly.