Voip Blog
What's VoIP Like On A T1?
Saturday, May 17, 2008
Several months ago, I was lucky enough to have three broadband lines coming into my house--cable Internet, DSL and a Covad T1. The Covad T1 was for their blogger relations program that I was in at the time. Pity I moved out of their service footprint, because it's difficult to go back to DSL and cable once you've had a taste of a T1.
Nominally speaking, DSL and Cable can be faster than a T1, which tops out at 1.544 megabits per second upstream and downstream. However, what a T1 lacks in raw speed--particularly on the downstream--it more than makes up for in latency. A T1 provides a consistent, low-latency connection to the Internet--something that's critical for high-quality VoIP calls.
When I had my Covad T1, given that I was the only one using it, VoIP was a dream. Many of the problems I had on my cable and DSL at the time--random increases in latency, jitter, and dropped packets--simply went away. I experienced the true power of voice over IP. And video? Even better. I did some tests with a couple of different video calling services over the Covad T1 and it worked absolutely fabulously.
Is a T1 shared? A dedicated like between you and the telco central office. You're sharing with everyone else at the Central Office once you're there, but a telco central office has enough bandwidth. Even so, you're much farther up the food chain than you are with a cable headend or a remote DSLAM, which are often connected with far less bandwidth.
I am lucky that my T1 was paid for as part of my participation in this blogger relations programs, because the T1 would have cost nearly $600 a month, and it varies greatly on location. When cable or DSL costs less than a tenth of that, and you're a consumer, and you tend to get more bandwidth with DSL or Cable, it's obvious which choice you'll make.
In all honesty, in my current house, both DSL and Cable provide very good voice over IP service. Your house is probably in the same boat. A T1 would likely be overkill, but in specialized applications, it may be just the thing you need.
