If this is a new T-1, check to insure that your programming and T-1 parameters matches what the providers is sending you or what you requested is what is being provided. Next, if you are lucky enough to have a T-Berd, use it to monitor the line, if you don't, try using a loopback plug (DB15) with pins 1 shorted with 3 and pin 9 shorted with 11, attached this to the T-1 card on the swith and run your diagnostic on LD 60, if it enables where all the channels go into idle for a DTI or maint/busy for a PRI card, the problem lies on the network side. If it does not, the problem lies in the card. Good luck.