First, I will describe the characteristics of the SSN2EGS2 single board of Huawei's SDHOSN1500 equipment. The characteristics of the single board when used on OSN series equipment are as follows, EGS2 belongs to the SDH Ethernet service processing board list, and the board supports the 1000BASE-SX/LX/ZX/VX Ethernet optical interfaces, which support self-negotiation functions and meet the IEEE 802.3z standard. Adopting pluggable SFP optical interface, the transmission distance of multi-mode fiber can reach up to 550m, and single-mode fiber up to 10km (40km and 80km optical modules can also be selected according to the actual needs). It also supports 1000BASE-T Ethernet electrical interface, and supports self-negotiation function, which can be self-negotiated to 10M, 100M or 1000M rate. Adopting pluggable SFP electrical interface, the transmission distance can reach up to 100 m. It supports self-negotiation, 1000M full-duplex, 100M full-duplex, 10M full-duplex (only N3EGS2 supports GE electrical interface). Supports self-negotiation, 1000M full duplex. Supports EVPL service with shared VCTRUNK. Supports EVPL service with shared PORT. Large support 2K blacklists and 2K static MAC addresses, shared 2K. blacklists of N3EGS2 single board only support destination MAC address checksum, not source MAC address checksum. The maximum number of VBs supported is 2, and the maximum number of logical ports per VB is 30. The following is an example of a get-not case encountered when using an Ethernet service processing board on an Optix OSN 1500 device.
Problem Description

After the SSN2EGS2 board has been operating normally on OSN 1500 network elements for more than two months, it has repeatedly reported COMMU_FAIL, LP_SLM_VC12, and ETH_LOS alarms and service interruption. Soft/hard reset and unplugging operations on the existing network failed to solve the problem.

Alarm information

COMMU_FAIL, LP_SLM_VC12, ETH_LOS.

Processing

1, replace the single board for SSN1EGS4 and other data single board, SSN1EGS4 on the software to do the anti-protocol message impact protection mechanism, so replace the single board after the problem is solved.

2, SSN2EGS2 single board software upgrade to version 5.51 or above.

1, analyze the black box of the single board, found that debugbuf.log records a large number of single board soft reset records, it can be seen that it is indeed a constant soft reset caused by the single board repeatedly reported COMMU_FAIL alarm, this alarm indicates that the master control and the data board of the EtherCommunication channel has been interrupted. Since SSN2EGS2 is a special single board, soft reset and hard reset have the same effect, both will interrupt the service. Therefore, when repeated reset faults occur on the EGS2 single board in the existing network, the service is interrupted repeatedly. The LP_SLM_VC12 and ETH_LOS alarms reported repeatedly are also caused by repeated soft reset of the single board.

2, from the debugbuf.log black box records, is the single board received a large number of protocol messages, resulting in the single board CPU occupancy rate is too high, thus reset occurs. 5.50 version of the software used by the SSN2EGS2 single board did not do the anti-protocol message impact protection mechanism, when the network may be due to the large number of broadcast storms generated by the protocol messages, the CPU will not be able to carry the load and reset from the black box records can also be seen in the soft reset, from the soft dog record, you can also see the soft reset. The black box record also shows that the process of processing protocol messages accounted for as much as 47.63% of the CPU resources when the softdog was reset. Therefore, after unplugging the board again, the protocol message impact is not lifted, and the EGS2 board will still experience the reset problem.

This chapter of related technical information and SDH equipment troubleshooting process by Shenzhen Optical Transmission Network Technology Co. Huawei SDH optical transmission equipment, SDH transmission equipment sales