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

[Steve Kann]

Kevin P. Fleming wrote:
> SteveK wrote:
>
>   
>> And the shortcut is added:
>>
>> A <-> C [media frames],
>>
>> Then, if C disappears off the network, then B would know it (via the
>> usual mechanisms, PING/PONG, etc), and would be able to notify A (and
>> vice-versa).  It seems like something to test in practice, though.
>>     
>
> I don't know enough about IAX2 to know whether this is true or not...
> under what circumstances are PING frames generated at all? They
> certainly aren't mini frames, so I can't see how A would ever send one
> directly to C.
>
> This is a valid concern... unless B (the machine in the middle) is
> sending PINGs to C and will notice that it has disappeared, then kill
> entire bridge.
>   
chan_iax2 and all IAX2 implementations send PING every few seconds;  10 
to 60 seconds or so, depending on the implementation.   chan_iax2 also 
sends these LAGRQ things, but they're pretty useless, and really ought 
to go. 

-SteveK