[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 Roger Burton
West
Sent: 28 May, 2011 23:50
To: asterisk-users at lists.digium.com
Subject: Re: [asterisk-users] Audio dropping

On Fri, May 27, 2011 at 10:31:57AM +0200, Mark Scholten wrote:

>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).

While the most usual problem is packet filtering / NAT, this generally
manifests as no audio at all in one direction, not a drop in mid-call.
But it's possible that one of the intermediate transit providers is doing
something "clever". (Disabling ping, as you mention in your later email, is
often a good indicator of a company with insufficient Clue.)

Are you in a position to tunnel the traffic over a VPN or similarly flat and
unfilterable network link? (This might be a good idea anyway.)
========

Hello Roger,

I'm not in a position to start doing that. The ping is disabled on the
firewall that is also doing the NAT (not something the provider does).
However the provider is blocking other things (incoming email for example,
for outgoing it is something I can understand).

The strange thing is it is dropping mid-call, that is the reason I don't
think it is only a NAT problem. Another network we use offered us a server
so we can test if it is related to the other network we use.

Regards, Mark