Our company does a lot of hosted VoIP. We have few problems with a T1 and a QOS router we install. Edgewater is our router of choice.

I don't think a T-1 going down all the time is a hosted VoIP issue. Even if you don't use VoIP, why would you put up with your T-1 going down all the time. Today the Internet is just as important to most businesses as their phone lines. Even the telco carriers are getting into Voip with their combined voice/data service.

When we install a system we make sure they have enough bandwidth, and we use our routers. In most cases we have very good call quality. If there is a problem we work to try and fix it as part of our service.

On the other side, I had 2 customers change their 6-8 business lines in their phone switch to Vontage over DSL. In both cases I put them back to analog POTS within a week.