[asterisk-dev] Jitterbuffer and FAXes with E1

[Steve Underwood]

Martin Vít wrote:
> Hello,
>
> I'm testing 1.4.5 (no modifications) with E1 card and i've found problem.
>
> I've this scenaro
>
> FAX -> SIP - ATA -> asterisk -> E1 port A --loopback--> E1 port B --> 
> iaxmodem.
>
>
> When jbenabled is off FAX is delivred OK. But when jbenable = on FAX are 
> failing in almost every line. I've compared WAV extracted from network 
> with WAV recorded (app monitor) before it gets to iaxmodem and there is 
> small differences. Network jitter is about 2ms (lab environment).
>
> Where could jitterbuffer modifies frames? I've tried to disable plc in 
> plc.c but without success. Any idea?
>   
This is correct behaviour. Most VoIP kit has the ability to disable 
jitter buffering when a FAX is in progress.

Steve