I've got what may seem like an obvious problem, but I'm trying to create a test network separate from my production environment. I have a spare 1720 router with a WIC-1DSU-T1 card. I have configured the FE0 interface for the new test network, and the S0 interface for the production network. I'm having trouble getting the serial interface to work. It is in alarm state. Is that because I need "something" on the other end to attach S0 to? Currently, it's just attached to a switch in the production environment. Any help is appreciated.