I just got word today about a free VoIP Test for Businesses(Yes, home users can take it too), at http://www.bandwidth.com/tools/voipTest; it measures the following criteria:

Bi-Directional Transfer Rate- How many VoIP conversations can be supported at the same time over current connections. Unlike other tests of this type, it runs in both directions at the same time.

VoIP Port Availability- Checks to see if SIP(Session Initiation Protocol) or MGCP(Media Gateway Control Protocol) connection ports are blocked by a firewall or NAT (Network Address Translation) device.

Latency- This checks to see how long it takes your voice to travel across VoIP lines and then back again.

If you don’t like that test, you can also check out http://testyourvoip.com or another cool tool at http://voipreview.org/voipspeedtester.aspx

At any rate, even though I am a home user, it is kind of neat to know that I can support up to 22 simultaneous conversations over my cable connection!