asterisk users - Jun 2006 - [HELP] - Sound cutting and dropping out - 1.2.7.1/Sangoma/PowerEdge 2850

Hi all,

We are running Asterisk 1.2.7.1 on our Dell Poweredge 2850 and are having
massive sound quality issues.

We are experiencing call quality issues for our remote location, namely
calls cutting out and breaking up for our agents.  The two main issues seem
to be 'popping' and 'dropping' - popping would be pops and
crackles on the
line, where dropping would be complete audio dropouts.  Most of the time,
these issues are occuring on ONE end of the audio stream.

The building houses about 60 users, 30 or so of which are on calls at any
one time. The location is connected to our main office via a 10Mbit
low-latency fiber trunk, and gigabit switches on either side of the fiber
endpoints. The floor at the remote location is all 100Mbit. Each user is
running a Dell Optiplex 170L, 2.8GHz or greater, XP SP2, 256MB RAM, and
Eyebeam 1.10n for their softphone, with ulaw as the codec.  We have several
managers that use Polycom IP501's, and they also are experiencing the
issues.

Server is a Dell Poweredge 2850, 2 x 2.8GHz Zeons, 4GB RAM, 73GB x 2 u320
hard drives in RAID-1, with a hotspare.  Running a stock Fedora Core 4
install, with only mysql and apache running.  Disabled ACPI and framebuffer,
and have the Sangoma card interrrupting on CPU0 only, all other devices
interrupting on CPU1.  Using onboard gig-E NIC with current drivers.

We are connected to the PSTN through a Sangoma A104D (current firmware),
using E&M Wink signalling.  Sangoma drivers are the current
2.3.4-betadrivers recommended by Sangoma.

I have spent the past three days working on this issue, and have opened the
issue with Sangoma and Counterpath - neither has been very helpful. I have
been monitoring our bandwidth closely - we're averaging around 3.5Mbit, so
we should have plenty available.  Sangoma statistics aren't showing anything
out of the ordinary - the system is performing as it should.

We have two other servers that are identical in configuration that serve the
main office, and they have no sound quality issues whatsover - the only
difference between the server having the issues and the ones that aren't is
the connection to the users - one is a local LAN connection, the other is
the WAN.

I have set up an extension that calls the milliwatt app, and records the
call to a file.  I can call in from either a Zap or SIP channel and have
sound quality issues, so the network is probably not causing the issue - a
purely Zap channel still experiences pops and drops.  Same with a purely SIP
channel.  The recorded call doesn't seem to reflect the audio issues - in
other words, pops on the phone are not necessarily recorded into the file.

We also have every call being recorded via the Monitor app - that was
disabled early this morning to see if some of the issues with Monitor were
causing problems - that made no difference either.

We just upgraded from 1.2.4 to 1.2.7.1 about a half hour ago - so far, no
difference.

If I cannot come up with something by close of business today, I will
completely rebuild the server from scratch, something I am not excited about
doing.

Otherwise, if anyone has any suggestions, questions, comments, or
encouragement, I am in dire need of any/all.

wes
whaut at fc500 dot com
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On 6/8/06, whois wes <whoiswes@gmail.com> wrote:
> I can call in from either a Zap or SIP channel and have
> sound quality issues, so the network is probably not causing the issue - a
> purely Zap channel still experiences pops and drops.  Same with a purely
SIP
> channel.  The recorded call doesn't seem to reflect the audio issues -
in
> other words, pops on the phone are not necessarily recorded into the file.
This is a very strange problem thank you for the very specific
description you gave, looks like it has to be that server hardware.

Have you tried possibly downgrading to Asterisk 1.2.6? not that I
think it would be the cause, but recompiling Asterisk is a heck of a
lot easier than rebuilding a server.

I would also try swapping out the power supply.

MATT---