I just got word today about a new VoIP Test for Businesses. Home users can take it too, straight from your web browser at http://www.bandwidth.com/tools/VoIPTest.
The free test is offered by Cary, N.C.-based Bandwidth.com, a Internet, wireless and VoIP services provider. 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 your connections ports are blocked by a firewall or NAT (Network Address Translation) device, rendering transmission via SIP (Session Initiation Protocol) or MGCP (Media Gateway Control Protocol), protocols difficult;
Latency- This checks to see how long it takes your voice to travel across VoIP lines and then back again.
OK, let's fire this baby up and take it for a spin over my Comcast cable modem.
OK, results are in.
Bi-Directional Transfer Rate- 85.51 kbps.
"VoIP phones upload and download voice data at the same time. The VoIP test you just ran included a bidirectional transfer test which simulated a number of two-way VoIP calls at the same time. Lower cost cable and DSL connections are usually restricted by their upload speed which can be significantly slower than their download speed. T1 and other symetrical business class circuits don't suffer from this restriction and hence can support more simultaneous VoIP phone conversations."
Lesson learned: I am running three VoIP lines here, but I guess I would do better if I sprang for a T-1. Those businesses down the street that have a T-1 are, by nature, presumably more prepared for VoIP than this SOHO focus group of one is.
VoIP Phone Capacity- 1 Phone, with a G.711 Codec.
"Voice data can be compressed before it is sent over your Internet connection thereby allowing more simultaneous phone calls. Generally, the more compression, the worse the sound quality."
Lesson learned: If I had the G.729a Codec, I'd be rockin' with a 2 Phone VoIP capacity.
Latency- 238.0 milliseconds (Poor).
"Latency is the 'round trip time' for data to go from your computer to the VoIP gateway and back again. Lower numbers are better as they represent delay before your voice is heard on the other end and a response can come back. Your latency of 238.0 milliseconds equates to 0.238 of a second, which is generally considered poor . Measurements up to 50 milliseconds are considered excellent while measurements between 50 and 150 are considered good. Worse than that is considered poor."
Lesson learned: Have mercy, Bandwidth.com. You really know how to hurt a geek. I call for T-1 now..