I am testing a controller t1 0 Interface when I configure the interface with the loopback local command the interface with come up and I can do a Perform Extended Ping Tests with out any problem.
The problem am having is when I remove the loopback local command and plug the Hardware to test the CSU/DSU Hardware Loopback the controller will not come up.
My question to all is when I plug the Hardware loopback in does the controller suppose to come up?
2) Is the led at the back is the controller supposes to light green?

http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00800a754b.shtml