Description of the problem

The local network system of a bureau consists of 2500+ equipments in 6 points of the ring multiplexing section system, one day there is a fiber break on the ring, the state of multiplexing section reversal is normal, but there is APS-INDI alarm and no PS alarm in F network element, and the service is interrupted from A to F.

PS aps-indi tu-ais

Processing

1, data setup errors, common causes protocol type mismatch, protocol stop, parameter setting errors, there are other inversion requests on the ring, or lock inversion, forced inversion, and other higher-priority settings, cross-page locking and so on.

2. Failure of the optical board of a station on the ring.

Failure of the cross board at a station on the ring.

Root cause

Failure of the light board.

Solution

1、The network diagram is as follows.

2, check the whole ring MSP parameters configuration is normal, check the MSP state is normal (inverted/through state).

3. Collecting Kbytes for analysis, we can see that F network element has never received Kbytes from eastward inversion request; only STATE_TRAN command is executed, but no XC_EXECUTE command is executed, and there is no switching of cross-page; and there is no switching of cross-page.

sys2 1401 SF_DET 0x0000 2013-05-30 11:50:41 0x1b1c990c

sys2 1402 K_SENDS 0xb450 2013-05-30 11:50:41 0x1b1c9b67

sys2 1403 K_DIR 0x0000 2013-05-30 11:50:41 0x1b1c9d1a

sys2 1404 K_SENDS 0xb458 2013-05-30 11:50:41 0x1b1c9ef9

sys2 1405 K_DIR 0x0002 2013-05-30 11:50:41 0x1b1ca0b0

sys2 1406 STATE_TRAN 0x040b 2013-05-30 11:50:41 0x1b1ca288

sys2 1407 SF_DET 0x0000 2013-05-30 10:51:38 0x1f14adb2

Analyzing the K bytes of the E network element, you can see that its eastbound can still receive K bytes, the problem is in the E and F sectors, generally at the receiving end of the problem is more likely.

sys1 2556 K_RECV 0xb458 2013-05-30 11:50:41 0x09d93b22

sys1 2557 K_DIR 0x0000 2013-05-30 11:50:41 0x09d93efb

sys1 2558 K_EXECUTE 0x0000 2013-05-30 11:50:41 0x09d94183

sys1 2559 XC_EXECUTE 0x0001 2013-05-30 11:50:41 0x09d9490a

sys1 2560 STATE_TRAN 0x0800 2013-05-30 11:50:41 0x09d95765

sys1 2561 STATE_TRAN 0x0810 2013-05-30 11:50:41 0x09d959ef

sys1 2562 K_RECV 0x0120 2013-05-30 11:50:41 0x09d96388

sys1 2563 K_DIR 0x0002 2013-05-30 11:50:41 0x09d9653c

sys1 2564 K_RECV 0x0230 2013-05-30 11:50:41 0x09d973fa

sys1 2565 K_DIR 0x0002 2013-05-30 11:50:41 0x09d975ae

sys1 2566 K_RECV 0xb548 2013-05-30 11:50:41 0x09d9929a

sys1 2567 K_DIR 0x0002 2013-05-30 11:50:41 0x09d9944f

sys1 2568 K_RECV 0xb54a 2013-05-30 11:50:41 0x09d9bd44

sys1 2569 K_DIR 0x0002 2013-05-30 11:50:41 0x09d9bef9

Through the analysis of the above K bytes, we can locate that the eastbound 6#S16 board of the F network element is faulty or the protocol problem.

4, the whole network start-stop protocol, still, inverted F network element cross board, still;.

5, segment by segment loopback to locate the failure point between E and F, configure the cross loopback to locate the eastbound 6#S16 board or cross board failure of F network elements.

6、Replace the 6#S16 board of F network element, the problem is solved.

Recommendations and summary

To deal with the problem of multiplexing segment inversion, first deal with the problem of MSP protocol layer, check the MSP inversion alarm and K-byte analysis to locate the faulty segment.

This chapter of related technical information and SDH equipment troubleshooting process by the Shenzhen Optical Transmission Network Technology Co., Ltd. collected and organized (www.opticaltrans.com), reproduced please retain! Our company specializes in the sales of Huawei SDH optical transmission equipment,SDH transmission equipment.