[asterisk-dev] New chan_iax media-only transfers: questions

[Steve Kann]

Hi, All,

    I haven't seen this code yet (I don't see the commit message), so 
please forgive me for not knowing exactly what changed..

Kevin P. Fleming wrote:
> John Todd wrote:
>
>   
>>   - is it possible for the central system to monitor or collect
>> statistics on call quality during the call even though it is not in the
>> media path?
>>     
>
> Possibly... I don't think we talked about that before Mark implemented
> it. However, the only frames that are redirected are mini-frames, so all
> the other signaling still passes through the central system.
>   

As Andrew mentioned in a later reply, IAX2 RR IEs are sent in full 
frames (PONG frames), and it would seem that these still go through the 
intermediary machines, where in theory they could be collected.

One thing, though, w.r.t Kevin's response:  At first, I'd think that tf 
all full frames still go through the "central" system, this is going to 
have a deleterious effect on jitter, if the network path between the 
endpoints is significantly different than the network path including the 
"central" server  (because some VOICE frames are full frames)   On the 
other hand, since only a small number of voice frames are full 
(typically once every 65 seconds), the jitterbuffer will probably just 
drop them and interpolate if they're late..

-SteveK