Nortel SONET AccessNode Manual page 42

2-24 DS3 tests, STS-1 tests, and optical in-bay tests
Procedure 2-3 (continued)
Testing optical protection switching
Step
10
11
12
Testing forced switching
13
14
15
AccessNode Vol 3B 323-3001-221 Issue 2.0
Action
Make sure G2 is the active circuit pack. If G1 is active, operate a manual
switch, by entering:
manual op g1 ↵
You are prompted to confirm the command.
y ↵
For OC-12 VTBM, both cards remain active with the green LEDs turned on.
For other OC-3/OC-12, the green (Active) LED turns off at OC-3/OC-12 G1
and lights on G2.
On the DS3/STS-1 test set, 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 DS3 or STS-1 continuity, press the Single Bit Error Inject button
three times on the DS3/STS-1 test set.
The DS3/STS-1 test set displays 3 bit errors received.
Force a switch to G1 by entering:
forced op g2 ↵
You are prompted to confirm the command.
y ↵
For both OC-12 VTBM and other OC-3/OC-12, the green (Active) LED on
OC-3/OC-12 G1 turns on and the green (Active) LED on the OC-3/OC-12 G2
turns off.
To verify the DS3 or STS-1 signal continuity, press the Single Bit Error Inject
button on the DS3/STS-1 test set three times.
The DS3/STS-1 test set displays 3 bit errors received.
Disconnect the optical test cord from the transmit (Out) connector on
G1 OC-3/OC-12.
For OC-12 VTBM, G1 and G2 are both active with green LEDs. The OC-12
Protection screen displays an R in the Forced field of G2.
For other OC-3/OC-12, the yellow loss-of-signal (LOS) LED on the G2 circuit
pack turns on. G1 OC-3/OC-12 remains active due to the forced switch. As a
result, DS3 signal continuity is lost.
—continued—