Nortel SONET AccessNode Manual page 78

3-16 Tributary and optical tests for VTBM rings
Procedure 3-2 (continued)
Performing optical interface receiver sensitivity tests
Step
Verifying the optical receiver
13
14
15
AccessNode Vol 3B 323-3001-221 Issue 2.0
Action
Reset the receiver test set.
The receiver test set indicates in process and displays 0 bit error.
Using the transmitter test set, inject three single bit errors.
The three errors are recorded at the receiver test set.
Reset the receiver test set and monitor for 15 minutes.
If you are testing with DS1s and they are not daisy-chained (that is, only 1
DS1 port is used for this test), monitor the system for 3 hours.
The display indicates 0 bit error.
If the requirement is not met, try the following in turn, and then repeat steps
13 to 15:
• Verify the optical meter calibration. Verify the digital or optical patch cords
to the test sets.
• Verify the optical patchcords for the OC-3 tributaries. Make sure of the
positive mating of fibers in optical connectors.
Replace optics units as per Module Replacement Procedures ,
•
323-3001-547, in Maintenance , Volume 5C.
CAUTION
Risk of increased optical errors
Received optical power should not exceed the overload
levels for optical interfaces meeting Nortel-to-Nortel
proprietary links:
NT7E01 OC-3 LR:
NT7E01 OC-3 IR:
NT7E02 OC-12 LR:
NT7E02 OC-12 IR:
NT7E05 OC-12 VTBM LR:
NT7E05 OC-12 VTBM IR:
These overload levels also apply to optical interfaces in a
Bellcore TR-NWT-000253 Midspan-meet specification, with
the following exceptions:
NT7E05 OC-12 VTBM LR:
NT7E05 OC-12 VTBM IR:
—continued—
− 10.0 dBm
− 8.0 dBm
− 7.0 dBm
− 4.0 dBm
0.0 dBm
0.0 dBm
− 8.0 dBm
− 8.0 dBm