User Manual

Airlink Pro T1/E1 Rack Mount Installer’s Guide
Operations and Maintenance
Rev. B - 1/97
4-7
Figure 4-1
Conventional Carrier Failure Response
If the microwave signal is lost between two AirLink Pro T1/E1 units
(Figure 4-2), both AirLink Pro T1/E1 units enter the local alarm state and send
an unframed, all-ones AIS (blue alarm) back toward its neighboring network
device. When the RF signal is regained, the AirLink Pro T1/E1 will come out of
the alarm state in about 10 ms.
Figure 4-2
AirLink Pro T1 Carrier Failure Response
If one of the three AirLink Pro T1/E1 Rack Mount loopback tests is active, AIS
is sent toward that portion of the link that has been excluded by the loop, so
the location and direction of the AIS depends upon which loopback test is
active. For more information about AIS and loopback tests, refer to “Loopback
Tests” in “Diagnostic Tools,” in this chapter.
Note that the other equipment in the network can take action upon receiving
alarm signals and might or might not restore service when the alarm clears.
Viewing the Event Queue
To view the event queue for the local unit, type the following command at the
AirLink Pro T1/E1 Rack Mount prompt: