Nortel SONET AccessNode Manual page 58

2-40 DS3 tests, STS-1 tests, and optical in-bay tests
Procedure 2-4 (continued)
Testing DS3 or STS-1 protection switching
Step
34
35
36
37
38
39
40
Testing priority DS3 or STS-1 switching
41
AccessNode Vol 3B 323-3001-221 Issue 2.0
Action
To verify that DS3 or STS-1 continuity for DS3s/STS-1s on the G2 mapper is
maintained (the DS3s/STS-1s that were forced onto the protection circuit
pack have reverted to the G2 circuit pack), press the Single Bit Error Inject
button three times.
The DS3/STS-1 test set indicates 3 bit errors received.
At the DSX-3/STS-1 cross-connect panel, connect the input of the test set to
the output of the first working G1 mapper.
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 for DS3s/STS-1s from the G1 mapper
is restored, (the protection mapper is again handling the DS3s/STS-1s from
the G1 mapper), press the Single Bit Error Inject button three times.
The DS3/STS-1 test set indicates 3 bit errors received.
Reinsert the first working DS3/STS mapper or STS-1 interface card into its
backplane connector.
The appropriate protection screen displays WTR (wait-to-restore) in the
AutoSw field.
After five minutes, the DS3s/STS-1s revert to the G1 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 G1 mapper from the protection mapper, press the single bit
error inject button three times.
The DS3/STS-1 test set indicates 3 bit errors received.
Note: Two working DS3/STS mappers or STS-1 interface cards are needed
to test priority switching. For simplicity, the second DS3/STS mapper or
STS-1 interface card is assumed to be G2. See Figure 2-3 on page 2-34 for
DS3 or STS-1 test setup.
If you have
only one working mapper
more than one working mapper
Review the priorities assigned to the DS3 or STS-1 groups on the appropriate
protection screen.
—continued—
Then
go to step 60
continue at step 41