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OSN3500 When the access point link 1 fails, the function of the LPT is to transmit the failure state of the access point link 1 to the docking device RS-B, that is, to realize the link state pass-through function. after the link between NE2 and RS-B is disconnected, RS-B starts the backup network and re-establishes the connection with RS-A on the backup network.
The LPT function is mainly reflected in the following two aspects:
- Access side
When the access point link 1 fails, RS-A detects the link failure at this end and automatically enables the backup network and tries to communicate with RS-B using the backup network. As for RS-B, it still uses the original network to communicate because it cannot obtain information about the link failure at the RS-A end, resulting in the communication being in a disconnected state.
After LPT is enabled, when the local transmission device NE1 monitors the link failure with RS-A, it sends an LPT message to the opposite transmission device NE2, and NE2 makes the port of RS-B detect the failure by closing its own port (Link Down). From there, RS-B also enables the backup network and re-establishes the connection on the backup network.
- Network Side
When a fault is detected in the service network and the network layer SDH protection inversion fails, the single board detects the network-side fault alarm and activates the LPT function and sends the LPT message to the opposite end to cut off the connection between the transmission equipment (NE1/NE2) and the docking equipment (RS-A/RS-B) at both ends, and they both use the backup network for communication.
Inconsistency in the LPT bearer mode may lead to failure of LPT reversal, and it must be ensured that the LPT bearer mode of the ports at both ends of the docking is consistent.
OptiX Products
- OptiX OSN 1500A/1500B
- OptiX OSN 2500
- OptiX OSN 3500
- OptiX OSN 7500
Fault Class
- LPT
- Ethernet Failure
Phenomenon Description
In R6 and pre-R6 versions, LPT does not work normally when the EFS board and the EMS4 board are interfaced. When the SDH layer service is disconnected, the two ends can be reversed normally. However, when disconnecting the network cable connection of an Ethernet port, the opposite end cannot be automatically inverted.
Cause Analysis
In R6 and versions before R6, the LPT function of the EFS single board supports only the MAC bearer mode, while the EMS4 single board supports only the GFP bearer mode. Due to the inconsistency of the supported bearer methods, these two single boards cannot be docked after the LPT function is enabled.
Procedure
- Set the LPT bearer methods of the ports at both ends of the docking table to be the same.
Reference Information
For R6 and versions before R6, you should avoid docking the EFGS veneer and the EMS4 veneer after enabling the LPT function.
The technical information in this chapter and the related SDH equipment troubleshooting procedures are provided by Shenzhen Optical Transmission Network Technology Co. Huawei SDH optical transmission equipment, SDH transmission equipment sales phone: 13430988088 Welcome to call!
