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Here I will introduce the main functions and working principle of Huawei SDH OSN1500 SSN1EMS4 single board, firstly, the single board needs to be inserted in the corresponding slot of the sub-frame according to the requirements, or the single board can not work properly.EMS4 single board can be used with the interface boards ETF8 and EFF8.There is no dialing code and jumper for single board setup on the EMS4 single board.EMS4 can be be plugged into slots 1 to slot 4 and slots 15 to slot 16 of the subrack with a bandwidth of 1.25 Gbit/s, and into slots 5 to slot 6 and slots 13 to slot 14 of the subrack with a bandwidth of 2.5 Gbit/s. The single-board laser safety level is CLASS 1, and the single-board optical ports have a maximum output optical power of less than 10 dBm (10 mW). When the EMS4 single board is protected by BPS, both the GE interface and the FE interface are protected by the single transmitter-receiver method. Since EMS4 single board has a large number of ports (4GE&16FE), it may be connected to multiple communication devices at the same time. Under normal circumstances, it is the main single board that works, and at this time, services are transmitted in both directions on the main link. However, on the standby link, on one hand, EMS4 will shut down the transmission of all ports, so the ports of the opposite end equipment veneer will be in the Link down state; on the other hand, the opposite end equipment veneer will enable its transmission, although it does not transmit services, but the receiving side of the standby EMS4 will not be in the Link down state.EMS4 veneer is an Ethernet switching processor board, which is mainly used for solving the problems of Ethernet service access, bandwidth management and Ethernet service management. The EMS4 board is an Ethernet switching processing board, which is mainly used to solve the telecommunication applications such as Ethernet service access, bandwidth management, and Layer 2 switching of Ethernet services. Typical networking applications of Ethernet switching processing board are shown in Figure 1, which can realize Ethernet access, aggregation, Layer 2 switching of Ethernet data, port isolation, flow classification, data flow control, VLAN management, priority configuration and other data features, as well as data encapsulation/de-encapsulation, virtual cascade, SDH mapping/de-mapping, etc. It can also be connected with broadband access equipment. At the same time, it can be docked with broadband access equipment and digital communication equipment to provide a network-wide solution.
Problem Description
Networking situation:
Failure phenomenon: OSN1500 equipment EMS4 single board Vctrunk port enable loop detection and loop port shutdown function, OSN500 equipment Port3 port before the loopback, two services are through, Port3 port after the loopback, Port2 service is not through!
Failure Information
OSN1500 equipment EMS4 single board Vctrunk3 port reports ETHOAM_VCG_SELF_LOOP, parameter 01 00 02 01 FF
1. After the MAC loopback, verify the self-learning MAC address of the OSN1500 device, and it cannot learn the MAC address of the Vctrunk2 port, suspecting that the loop port shutdown function is not working;
2. Check the RMON performance of the Vctrunk3 port of the EMS4 single board of the OSN1500 device, and there is no sending or receiving packet, which indicates that there is no problem with the loop port shutdown function;
3, view OSN500 equipment EFT single board Port2 port RMON performance, no receiving packets, on behalf of the S3700 did not send packets to the transmission equipment;
4, digital communication professional engineers to help analyze the reasons for the S3700 did not send packets, found that the S3700 device opens the STP function, when the network is detected to have a loop, the port is closed resulting in the absence of packets;
5. After closing the STP function of S3700 equipment, the service is normal.
Avoidance measures: 1. When configuring private network services, loopback operation is not allowed, which can easily cause broadcast storms and affect the services. 2. For the networking situation of this case, if loopback operation is required, not only should the loop detection and loop port shutdown functions of the transmission side equipment be turned on, but the STP function on the switch side should be turned off.
The related technical information and SDH equipment troubleshooting procedures in this chapter are provided by Shenzhen Optical Transmission Network Technology Co., Ltd ( www.opticaltrans.com), please retain! Huawei SDH Optical Transmission Equipment,SDH Transmission Equipment Sales
