The Optix OSN3500 ECC function enables flexible networking, and ECC communication between elements can be carried out through optical ports. On some special occasions, the OAM information of third-party equipment can also be transmitted.ECC is Huawei's proprietary protocol stack, and it is the most widely used and mature ECC communication solution for Huawei's transmission equipment.HWECC uses NE IDs to identify network elements, and automatically establishes routes, which makes it easy to use.ECC can realize flexible networking, and ECC communication can be carried out among the elements through the optical ports. On some special occasions, OAM information of third-party devices can also be transmitted. When network management information is transmitted between Huawei optical transmission devices, a gateway network element must communicate with the network manager. The network manager connects the gateway network element via Ethernet to realize testing, management, and maintenance of the entire network. Non-gateway network elements connect to the gateway network element through ECC to realize the transmission of network management information.

OSN3500 ECC Networking Mode

• Networking modes: network cable direct connection, HUB connection and network cable serial connection.
• Expansion mode: automatic mode, specified mode and adaptive mode.
• Network size: the sum of server and client must not be larger than 8. When the size is not larger than 4, you can use automatic or manual method; when the size is larger than 4, you must use manual method.

Problem Description

On a certain day, an OSN 3500 device gateway is modified to the standby gateway on U200, and it is found that the network element is offline and cannot be monitored.

Processing

1. Check the ECC link management of the OSN 3500 upstream site network element, and it can query the unmanaged network element, which indicates that there is no failure in the master control of the unmanaged network element and the optical board.

2. Check the ECC link management of the standby gateway network element, and the off-pipe network element cannot be queried, but the upstream station network element of OSN 3500 can be seen on the gateway, and the distance is 10.

3. On the U2000, the OSN 3500 device gateway is back to the main gateway, and the network elements can be monitored normally, open the OSN 3500 network element manager, and in the ECC link management, you can query the main gateway and the upstream network elements, but you can't query the standby gateway network elements, and you can carefully check and find out that in the OSN 3500 ECC link management, the distance is 6 at the maximum, and the distance to the standby gateway is 11.

4. Use the command: cm-get-maxdist to view the OSN 3500 maximum routing distance setting, as shown in the following figure:

It is found that the maximum routing distance of the network element has been modified to 6. The default maximum routing distance of the network element should be 64. After the distance is restored to 64 by using the command cm-set-maxdist, the OSN 3500 device is monitored normally through the standby gateway.

Root Cause

The OSN 3500 cannot be monitored by the standby gateway due to insufficient maximum routing distance.

Solution

Modify the maximum routing distance to default 64, then monitor normally.

Suggestion and Summary

In the scenario that the network element cannot be monitored, if the upstream site can query the network element, you can consider whether the maximum route restriction causes the network element cannot be monitored.