[asterisk-users] Cepstral's Allison is having trouble speaking clearly

[Vahan Yerkanian]

Todd Reese wrote:
> Hi all,
> 
> I have just install and licensed Cepstral's Allison08kHz on my Asterisk
> 1.4.11 system.
> 
> I can call the Allison's extension from my Grandstream IP Phone and she's
> clear as a bell, but when a call to her extension traverses through one of
> the Linksys/Sipura 3102 or 2002, she's got the jitters bad.
> 
> The SPA-202 has only an extension phone on it and the SPA-3102 is my FXO
> from my Vonage Motorola box.
> 
> 
> Any clues where to start looking to clear this up?

Make sure that you have RTP Packet Size changed to 0.02 from the default 
0.03 in the Sipura SIP tab. This is known to cause jitter with Asterisk.

HTH,
Vahan