[asterisk-users] Bad audio quality on SIP

[Stephen Bosch]

Michelle Dupuis wrote:
> The problem will be on the "outside" of your Asterisk PBX.  In other words,
> your asterisk server's external NIC (or if just one NIC), connection to your
> firewall/router,  to you voip provider.
> 
> You need to run tracert's from your Asterisk box to your voip provider.  
> 
> QoS on the windows clients is useless (and doesn't matter in this case).
> QoS is often misunderstood.  Without knowledge of the protocols you are
> running, your network admin could not have setup the router/firewall to
> shape traffic properly.  Prioritizing based on QoS bits offers minimal
> benefits.

This has been my experience also.

The only place where I have seen QoS provide any real advantage is in
enterprise environments where one administration team controls all the
network hardware and VOIP is only used to the network boundary.

QoS is a fantastic sales tool for Cisco, though!

If you are having trouble with chops, blips, and other call quality
problems, you have a connectivity or configuration issue that QoS will
not help.

-Stephen-