Any Experience with Telco T1 SIP Trunks? AT&T Specifically?

[CaneData1]

I have clients in the US and overseas, doing well with internet services like flowroute.com and sotel.com.

However, other clients require a bit higher quality / reliability. About 2 years ago I went through a certification process for an M8L with Paetec (now Windstream) and successfully deployed an M8L with their "SIP over MPLS" product (Now called "Dynamic T1 SIP").

Basically their Adtran box connects to the Epygi's LAN, providing a local IP for SIP gateway, and feeds the traffic thru their T1 and QOS network to wherever the SIP carrier box is.

This has worked flawlessly and I recommend it often. But some clients are stuck on a T1 contract with AT&T or other providers. I inquired with AT&T about similar services but they cite long, overkill testing procedures and have very poor followup.

Has anyone used similar ITSP services from local Telco or Big Slow AT&T?

Regards,

[CaneData1]

Note: I am familiar with the guides on:

Support Center » Downloads » Support Resources » ITSP Config Guides

But lookign for info on AT&T! :-)