A MAJOR alarm on a trunk indicates that alarms on these trunks are not downgraded by set options and that at least 75% of the trunks in this trunk group are alarmed.
For systems supporting circuit packs:
If ATMS testing is enabled, check the error log for ATMS errors 3840 and 3841. If the error log indicates that measurements exceeded acceptable thresholds, and no other trouble is found with test trunk, run the ATMS test call with test analog-testcall port location full.
Note:
Many trunk problems are caused by incorrect settings of parameters on the trunk group administration screen. Settings must be compatible with the local environment and with parameter settings on the far end.
Analog CO trunks are 2-wire analog lines to the CO which support both incoming and outgoing calls. CO trunk MM711 Analog Media Modules have eight ports.
Not all tests in the demand test sequences are applicable for media modules. These tests will abort with error code 1412. This error can be ignored.
The following sequences show the interactions between the switch and the CO during call setup for both loop-start and ground-start trunks.
