T-1 connection

We have a new T-1 circuit installed and our ISP has failed to get our cisco 2600 router here on time. I would like to try to borrow the equipment necessary to temporarily use the circuit until our ISP gets it together.

I have a T-1 circuit live and tested from the LEC installed with what appears to be an ordinary CAT 5 cable coming out of the T-1 card at the Demarc. A friend loaned me a T-1 CSU/DSU but, the ports on this unit don’t appear to accept an RJ45 type connector? Can someone helpme out by pointing me to information about the cables and interfaces that I might need to scrounge up to get my company back online? I thought that if I got a CSU/DSU and a router/bridge I could start using the circuit but, this is all new to me.