During the test of a certain NG-DWDM system, the functions such as ASON, Ge-ADM and broadcasting need to be verified.
The board for the test is LOG and the NE software version is V1R3.
Faults occur during the test of the ASON switching, Ge-ADM, or the broadcasting function. That is, these functions are unstable during the test. Test meter used in the test shows that the link is sometimes up and sometimes down.
The electrical cross-connection error involves the central cross-connect board and the backplane as well as the LOG. Do as follows to identify the fault:
1. Reset the LOG in slot 6 by reseating it. The fault persists.
2. Replace the LOG, and the fault persists.
3. Reset the cross-connect board or use the standby cross-connect board. The fault persists.
4. Slot 6 is suspected to be faulty. Remove the LOG from slot 6 and insert it in Slot 11. After re-configuration, all the ASON, Ge-ADM and broadcasting tests are successful.
This proves that slot 6 is faulty.
First check the optical power and OSNR to make sure that the fault is not caused by improper optical power.
After repeated configuration and test, it is found that NE1-slot-6-LOG is used during the test of the ASON switching, Ge-ADM, or broadcasting function, In addition, the lp-to-ip cross-connection is configured on the LOG.
Test the link by using a test instrument and performing software loopback. The service on the test instrument is normal when an outloop is configured on the client side of the LOG, whereas the service on the test instrument is interrupted when an inloop is configured on the WDM side of the LOG.
The symptom indicates that the electrical cross-connection configured for the LOG does not take effect. Thus, the board is suspected to be faulty.
Though the slot fault is not easily identified, it can be quickly located by means of loopback and replacement.