Fletch

A couple of things to remember.

RED ALRM is a local alarm. It means there is no signal present at the T1 card in the PBX. Most likely the problem is towards the CO. A loopback plug will confirm this. If you plug in the Loopback, and the system goes out of RED, then there is problem with the circuit.

YELLOW ALARM - A lot of folks get this wrong. It is a RECIEVED ALARM. Just by the fact that you are getting it, means you see the other side. What it is telling you though, is that the far side does NOT see you and they are sending a YELLOW to let you know that.

T1 (Non PRI) - If you loop these back, the channels will go idle and you WILL TRY TO SEND CALLS! be careful when looping back during business hours when this T1 is still a possible route choice.

T1 (PRI) - Looping these back will only bring the T1 in service. The DCH will not establish, since it is seeing itself, and one side has to be master and one side has to be slave. Looping a PRI causes the DCH to see a Slave to Slave, or Master to Master DCH connection, and it will not bring the channels into idle.

As Rix suggested, always have a loopback plug handy for each side of each interface you have, as well as all of the possible gender configurations.

these are easy to make, and a life saver!