Description of the problem

After the N1EMS4 single board is configured with BPS protection using the FE electrical port, it is found that the port of the standby single board keeps reporting ETH_LOS alarm, and when it is forced to invert, it can be successfully inverted, but it cannot be inverted successfully after disconnecting the network cable of the main channel. The host version is R8.

Process

1. Check the port working mode of the host single board is 100MFULL, because for 100M electrical ports, only 100MFULL BPS protection is supported;

2, BPS protection is divided into master mode and slave mode, in the case of BPS master mode, the standby port of the single board is shut down transmission, resulting in the opposite end is LINK_ERR or ETH_LOS state, but the opposite end of the standby port will not shut down transmission, so as to ensure that the master and standby ports are LINK_UP state, the master and standby board state are all available state;

3. In the BPS slave mode, the backup port of the board will not shut down the transmission, and it is always in the open state. When the reversal occurs, the master port of the board will be closed for 3 seconds and then opened again;

4. After confirming that the BSC of the C network of our company is docked, in the R8 version of OSN equipment, the BPS of the FE electric port only supports the BPS main mode of 100MFULL, and in this mode, the backup port is always in the state of shutting down, which results in the port of the docked BSC equipment reporting the ETH_LOS alarm, and the BSC equipment, upon receiving the LOS alarm, also shuts down its own transmission, which results in the backup port on the transmission equipment always shutting down its transmission. When the BSC device receives the LOS alarm, the BSC device also shuts down its own transmission, resulting in an ETH_LOS alarm being reported on the backup port of the transmission device, and the single board remains in an unavailable state;

5. Upgrade to V1R9C04 version to support the slave mode of FE electrical port to solve the problem.

Root Cause

In the R8 version, the BPS of the FE electrical port only supports the BPS master mode of 100MFULL, in which the standby port is always in the state of shutting down, resulting in the port of the docked BSC device reporting the ETH_LOS alarm, and the BSC device receiving the LOS alarm also shuts down its own transmissions, resulting in the standby port on the transmission device reporting the ETH_LOS alarm all the time, and the single board The single board is always in an unavailable state.

Solution

Upgrade to V1R9C04 version to support the slave mode of FE port to solve the problem.

The related technical information in this chapter and the troubleshooting process of SDH equipment are collected and organized by Shenzhen Optical Transmission Network Technology Company Limited (www.opticaltrans.com), please retain the reproduction! Our company specializes in Huawei SDH optical transmission equipment, SDH transmission equipment sales.