[asterisk-users] bad case of buzzing

[Louis-David Mitterrand]

Hello,

We are at wit's end on this. One (and only one) of our five asterisk 
installation is giving us real headaches. Buzzing and/or choppy sound 
interfere with conversations. I recorded some conversations with 
monitor() and no problem whatsoever appear in the recording, while the 
local user was hearing the buzz and half my words.

This is a 1.2.16 installation with mISDN but mostly using SIP to our 
central PRI-equipped asterisk. Phones are Polycom 430, 601, Cisco 7960, 
7912 all to the latest firmware.

We tried everything: changing the switch, network cards, auditing every 
network drop with fluke, re-certifying our wan, swapping some phones to 
no effect.

Has anyone gone through that ordeal?