To do this on a T-1 your carrier must support it in-band, very few did back in the day... I doubt any do now with the how rare T-1 is used for voice now days, it was a struggle to get them to support it in the 90's and once PRI's became commonplace you just don't hear about this anymore. You would be better off to upgrade to a SX-200ICP with a PRI and reuse the cabinets than to try to get this to work.