VOIP Network Traffic Management Problem

A couple of questions:

1). where does the voip terminate on the IP side? are there a bunch of IP phones connected to a 10/100/1000 switch or is there a single gateway (PC or dedicated box) with a single connection to the ip side?

2). What speed is your Local IP Network operating at (your main ethernet switch)? is it 10 Mbps, 100 Mbps or 1000 Mbps (1 Gbps), or a combination of these?

OK I guess I have a third question as well:

3). What kind of traffic do you have going on between the computers on the ethernet? The reason I ask this is if there is lots of IP traffic going thru the local ethernet switch you could be getting network congestion there BEFORE the QOS is applied at the router. Most ethernet switches have NO QOS (unless your switch is a "smart switch" with QOS built in.

Hope I am not being too confusing here.

Mark E.

We have a 10/100mbps switch, and I must admit, I did not consider our internal traffic. We run a peer-to-peer network, which is not at all elegant, and we mostly use one computer as our file server for critical data files. However, in looking at my network monitor, it does not look to me as though our internal traffic should be interferring.

Assuming away the internal traffic as the problem, my primary question is this: If I can control traffic into and out of our local network, which all flows directly through our Netgear Firewall device, will that not control the priority handling of all the packets coming and going from our phones to the internet backbone, or will I also have to pay to have class of service installed by ATT?

All our phones connect to a 24 port switch, which is immediately behind the firewall.

Thank you.

Tom