Nortel SONET AccessNode Manual page 55

Procedure 2-4 (continued)
Testing DS3 or STS-1 protection switching
Step
16
17
18
19
20
21
22
Action
To verify that DS3 or STS-1 traffic is lost, press the Start/Stop button twice on
the DS3/STS-1 test set, to reset the error count.
The DS3/STS-1 test set shows a high error count.
Release the lockout, allowing the automatic switch to protection by entering:
lockout re g1 ↵
y ↵
When you release the lockout of the first working mapper, the DS3s/STS-1s
normally handled by that mapper are rerouted to the protection mapper. The
appropriate protection screen displays an asterisk (*) in the AutoSw field.
Alarms clear.
Press the Start/Stop button twice to reset the error count to zero.
The DS3/STS-1 test set indicates in process and displays 0 bit error.
To verify that DS3 or STS-1 continuity exists and that the DS3s/STS-1s are
rerouted to the protection mapper, press the Single Bit Error Inject button
three times.
The DS3 /STS-1 test set indicates 3 bit errors received.
Re-engage the first working DS3/STS mapper or STS-1 interface card into its
backplane connector.
After five minutes, the DS3 or STS-1 traffic reverts to the first working
DS3/STS mapper or STS-1 interface card and the appropriate protection
screen displays a dot (.) in the AutoSw field.
Press the Start/Stop button twice to reset the error count to zero.
The DS3/STS-1 test set indicates in process and displays 0 bit error.
To verify that DS3 or STS-1 continuity exists and that the DS3s/STS-1s have
reverted to the first working mapper, press the Single Bit Error Inject button
three times.
The DS3/STS-1 test set indicates in process with 3 bit errors received.
—continued—
AccessNode Site Testing Procedures 323-3001-221 Issue 2.0
DS3 tests, STS-1 tests, and optical in-bay tests 2-37