[asterisk-users] Poor sound quality on incoming calls

[Ryan Parlee]

Hello,

I am experiencing extreme jitter/slowdown on Playback() or Background().
I've looked thoroughly on voip-info.org and elsewhere for help regarding
this issue but cannot figure this out.  I can make outgoing calls with no
problems.

I am running Linux 2.6.18-4-686 and Asterisk 1.4.8 and I do not have any
zaptel hardware installed.  

When I run without ztdummy I experience poor sound quality and sound
overlaps in Playback() or Background().  For example, the default busy
message says "The person at extension, at extension, at extension, is
unavailable, please press.. the pound key, the pound key, the pound key"

When I run with ztdummy, the default busy message says "The perrrrson
aaaaaaat extension iiiiiis unnnnnnnavailllllable..."


I found sites talking about conflicts with Asterisk and ACPI on 2.6 kernels
so I rebuilt my kernel with all ACPI and APM options turned off.  

When I run zttest I get the following:

Opened pseudo zap interface, measuring accuracy...
-34.204102% -20.263672% -24.218750% -26.586914% -23.852539% -13.256836%
-25.207520%
-13.366699% -15.441895% -14.550781% -22.351074% -21.765137%
--- Results after 12 passes ---
Best: 0.000000 -- Worst: -34.204102 -- Average: -21.255493



Any help would be appreciated!

Thanks, 
Ryan