[asterisk-users] Webrtc and adventures with Asterisk 11

Johan Wilfer lists at jttech.se
Mon Apr 14 03:56:11 CDT 2014


I spent the past week experimenting with webrtc + asterisk 11.9.0-rc1 + 
opus/vb8 codec patch. This is interesting technology and I try to find 
out how to connect all the moving parts.

Neither sipml5 or jssip works with calls to asterisk, audio/video 
doesn't matter.
WARNING[977][C-00000005] chan_sip.c: Rejecting secure audio stream 
without encryption details: audio 35684 RTP/SAVPF 109 0 8 101
--> Asterisk sends "SIP/2.0 488 Not acceptable here"

I've tried both sipml5 and jssip softphones and they both work. Even 
video + confbridge works with some minor quirks (lost connections 
sometimes, I guess plain old nat issues).
Just relaying audio+video with confbridge to a handful of participants 
seems to use quite a bit of cpu thought.

This works, but Confbridge is not very happy about a channel with video 
(vp8) and not audio and is printing this 80 times a second:

WARNING[8919][C-00000000] channel.c: Unable to find a codec translation 
path from (vp8) to (slin)
WARNING[8919][C-00000000] chan_sip.c: Asked to transmit frame type slin, 
while native formats is (vp8) read/write = unknown/unknown
WARNING[8919][C-00000000] channel.c: Don't know any of (vp8) formats

How do you think about adding webrtc to a existing Asterisk/Kamailio 
environment? Do you use kamailio (websockets) as a front, a dedicated 
webrtc asterisk or something like webrtc2sip?

How do you use / plan to implement webrtc in your environment?

Any feedback is welcome. Thanks!

Johan Wilfer

More information about the asterisk-users mailing list