[cisco-voip] Weird Conference Voice Quality

[Vandy Hamidi]

Hey guys,
I'm having a weird problem that isn't making sense

I have a 6608-T1 blade in my main office performing conferencing for
most of the remote offices in the company.  I know, not recommended, but
read on.

All the offices are connected Hub/Spoke to the main office and I have
QOS setup (supposedly correctly) on my wan links and call quality is
great.  I've tested the QOS by maxing out the line during voice calls.

We've been receiving user complaints of voice quality problems.  Cutting
out, delays, overall chopping communication.  All these complaints are
when they are on conference calls.

We've performed testing and during high wan usage the conference call
quality becomes horrible to/from the remote sites and sometimes for all
users for example I'll have a hard time understanding a conference
attendee in my own office.
We're able to reproduce with windows copies during conference calls.

1) Why is the voice quality ok with phone to phone calls, but become
horrible during a conference call.
2) Does the 6608-T1 blade change/alter the QOS/TOS bits on the packets?
3) Why would this issue affect local attendee conference quality when
everyone is connected to the same switch where the 6608 blade is.

TIA,

	-=Vandy=-