[asterisk-users] Audio dropping

[Mark Scholten]

-----Original Message-----
From: asterisk-users-bounces at lists.digium.com
[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Ishfaq Malik
Sent: 27 May, 2011 10:54
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [asterisk-users] Audio dropping

On Fri, 2011-05-27 at 10:31 +0200, Mark Scholten wrote:
> Hello,
> 
> We see some strange behavior with phone calls, we use Asterisk 1.8.3.3.
> 
> SIP clients (all behind NAT at different locations, so not a single 
> NAT solution is used):
> - x-lite
> - linksys pap2t
> - polycom kirk (multiple type numbers)
> - polycom (multiple type numbers, hardware phones)
> 
> Our Asterisk servers stays in between (some calls are recorded). 
> Asterisk is running on a physical server (no virtual server software) with
"old"
> hardware (Xeon 3.2 GHz with hypertrading and 4GB RAM, mainly used for 
> buffers). We use a MySQL backend (CDR records are stored in it and SIP 
> users are stored in a MySQL database).
> 
> We use a SIP provider with a trunk for outgoing and incoming calls, 
> this is also an Asterisk server if I'm correct. We currently do around 
> 1000 calls a week and max. do 10 calls at the same time. The Asterisk 
> server is not behind a NAT.
> 
> What could the reason be audio in 1 direction is dropping? (Normally 
> from the Asterisk server to the mentioned SIP clients.) No clear 
> information is in the logs (it is like the call ended normally) and 
> not all calls are having problem (most not, but it happens to often 
> for us to start using VoIP more at the moment).
> 
> To test if it was the firewall we disabled the firewall on the 
> Asterisk server and moved the Asterisk server before the other firewalls
we have.
> 
> What could the problem be? And even more important what could solve it 
> (and/or explain it)?
> 
> Kind regards,
> 
> Mark Scholten
> 

Hi

Are the broadband connections to the target SIP extensions dedicated for
VoIP or does any other traffic run over them?

We tend to find that 80% of call quality issues are caused by the broadband
connection.

A good diagnostic tool to keep an eye on the broadband connections involved
is smokeping http://oss.oetiker.ch/smokeping/

We find it an absolute godsend.

===============

Hello,

Ping is disabled on the location with most call problems (filtered). A few
clients with dedicated audio broadband connections have the same problem
compared to "shared" broadband connections.

This makes it very difficult to find the problem. A supplier we use offered
to test it with a server from them, if that solves it it was probably a
network issue.

Regards, Mark