I have a facility that has WAN connectivity problems. I have an AT&T Frame-relay MPLS WAN. If I have the circuit connected to the router via a WIC-1DSU-T1-V2 the circuit will not come up. If I connect the same circuit to the same router via a VIC-1MFT-T1 the circuit will come up. Any ideas? This just all of a sudden happened. We had the circuit connect via the 1DSU for many months without problems. AT&T is saying that everything is fine on their end.