OK. . . . . I couldn't find it on the site you provided but I did an internet research on the Model Number (77961053) Here are some of the specs on it - Now What?

Framing Format D4, ESF, AT&T 54016,ANSI T1.403

Line Rate T-1

Line Coding Format AMI,B8ZS

It is working with AT&T - but not with Bell South because I provided them with D4 SF AMI information as my vendor told me it was.

Now it's looking like maybe I gave them the wrong inoformation???

Thanks!!!!