MAINTENANCE

5.Listen for dial tone from the accessed trunk. If dial tone is not present, isolate the fault to a trunk port CP or location in the trunk access equipment, etc., using a test set.

6.If dial tone is present, dial a working outside number. Verify that the call is complete.

7.If trunk is busy, fast busy tone is heard. If a nonport trunk was dialed, fast busy tone is heard.

Incoming Trunk Problems

Symptoms:

Incoming trunks (of any type) not working properly.

Procedures:

1.Place an incoming call through the troubled trunk.

2.At the SAT, check the trunk translations to be sure this trunk has been properly translated. (See the Administration Manual.)

Error Log Interpretation: Loop-Start Trunks

Procedures:

1.Check Error Log for messages pertaining to loop-start trunks.

2.If “no loop current on incoming call” is displayed, no loop current was detected on an incoming call. The CP detected ringing, but not loop current when it closed the loop. In this case, the CO facility is probably good, but either the current sensor on the CP is faulty or the CO battery circuit is faulty.

3.Switch trunk ports, and see if the problem moves to the new loop-

s t a r t t r u n k .

4.If the problem does not move, the loop-start CP is faulty and must b e r e p l a c e d .

5.If the problem moves, the fault is with the CO. Notify CO personnel through the proper channels.

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ADTRAN 25 manual Incoming Trunk Problems, Error Log Interpretation Loop-Start Trunks