Description of the problem

A provincial backbone network four-fiber multiplexing segment ring, A and B sites between the optical path is normal but in the inverted state is not restored, resulting in a large number of standby routes out of the present error code when the business flash off, the network configuration is as follows:

Alarm information

APS_INDI

Processing

Problem Location Processing

1), query the existing network alarms, the faulty network does not have LOS and other optical failure alarms, check the performance events of the inverted non-recovery site, A and B, there is no error code, the light-emitting power of the optical board is normal, and the received power is slightly higher, but acceptable; thus, the possibility of optical problems can be ruled out.

2), due to the failure of the network site, there is no single board anomaly alarm, initially we can rule out the possibility of optical boards, cross-boards and master control board problems;

3), exclude the above four points, then suspect that the multiplexing segment protocol has a problem;

4), through the script to collect K byte related data, sent to the company's R & D analysis, found that A (node number: 0) site received k byte information for the C (node number: 8) site of the k byte information, due to the line without anomalies in the alarm, preliminary suspicion of fiber optic connection error;

5), first of all, by modifying the J0 overhead byte between A and B, B and C intermediate line optical board to determine the cable connection relationship, found that there is no error in A, B (node number: 9) and the C site of the connection between the fiber, so exclude the possibility of first practicing the connection error;

6), through communication with the user to understand a message, C is later added to the multiplexing segment ring;

7), through the ptp command to collect the information of sites A, B and C, found that the multiplexing segment protocol of site B is not activated, so the multiplexing segment reversal between sites A and B has never been restored;

8), A westward work received SF_CLEARS, because the received K bytes are not legal, to discard, so has not been able to revert back to the work, so apsindi alarm has been present

The result of the collected data is as follows:

The node number sent by the single board in slot 13 at site B was 8 before the expansion.

1 4553 K_ON_OFF 0x000f 2013-3-26 9:47:19 0x09754577

1 4554 K_SENDS 0xb782 2013-3-26 9:47:19 0x0975459c // At this point in time 2012-3-26 9:47:19 the node number is still 8

1 4555 K_DIR 0x0001 2013-3-26 9:47:19 0x097545a9

After the expansion on the night of March 26, the node number changed to 9 at the following point in time:

1 4615 K_SENDS 0x1892 2013-3-27 10:34:59 0x0763fc06

1 4616 K_DIR 0x0001 2013-3-27 10:34:59 0x0763fc16

1 4617 K_SENDS 0xb89a 2013-3-27 10:34:59 0x0763fc75 //Node number 9 at 2012-3-26 9:47:19.

1 4618 k_dir 0x0003 2013--27 10:34:59 0x0763fc84

A westward working received K bytes, the red part indicates that the received K bytes node number is 8. Before I thought it was a misconnection, but of course the more common ones are also misconnected.

1 2799 SF_CLEARS 000000 2013-8-28 12:3:21 0x687e2c98

1 2800 K_RECEIVED 0x0080 2012-8-28 12:3:21 0x687e2d67

1 2801 k_dir 000000 2012-8-28 12:3:21 0x687e2d79

1 2802 SD_DETECTED 000000 2012-8-28 12:3:21 0x68800c33

1 2803 sd_clears 000000 2012-8-28 12:3:31 0x69184e28

Queried the Kbytes sent by the single board in slot 6 at site B and found that 0x0080 was sent by this network element

:nptp:6,8,b5,1.

ncmd 0: 06 08 b5 00 00 01 00 80

Combined with the fact that I didn't see a record of the reuse segment restarting on March 26th before, this proves to be the cause.

The entire four-fiber multiplexed segment ring needed to be deactivated once for the protocol, and the problem was solved.

Root Cause

The following are possible reasons why a multiplexed segment inversion does not recover:

1), Optical path problem

2), optical board problems

3) Cross-board problem

4), the main control board problems

5), multiplexing segment protocol problems

Suggestions and Summary

1. When doing topology transformation on any group network, if the network has self-healing ring protection, it is necessary to do the inversion test to determine whether the protection of the network is normal or not after the transformation is done;

2. In doing the operation of multiplexing segment ring removal and replacement and addition, there are a few things that need to be noted:

1), confirm that the fiber connection is correct;

2) Confirm that the protocol of the multiplexing segment on the ring is consistent;

3), confirm that the multiplexing segment node parameters are set correctly, preferably in counterclockwise order from small to large;

4), the multiplexing segment protocols are started normally;

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