Description of the problem

Network elements: two OSN3500, one OSN7500II.

Networking mode: chain networking, OSN3500---OSN7500II---OSN3500.

Fault: When configuring MS-PW service, Tunnel1 from OSN3500 to OSN7500II and Tunnel2 from OSN7500I to OSN3500 have been established.

In the S-PW node, in this case the OSN7500II node, an error is reported when configuring MS PW.

As a result, the service cannot be configured during the configuration process.

Alarm messages

No

Processing

1. Check the service configuration on the network element. After checking, there is no other service, so exclude the cause of the first error.

2. Check the configuration of the services on this network element, and there is no service with duplicate PW ID.

3. In the process of configuring the E-LINE services carried by PWs separately, the PW IDs of the Ingress node's outgoing label and the Egress node's outgoing label at both ends are duplicated.

In the process of configuring the E-LINE services carried by the PWs separately, the out label of the Ingress node and the in label of the Egress node at both ends must be the same. Therefore, when you follow the configuration steps in the product documentation, there will be a Dupiticate PW ID error.

Therefore, after thinking about it, when configuring the S-PE node, do not match the PW ID PW Label of the T-PE node, and when configuring the S-PE node in this way, do not use the same PW ID PW Label as the T-PE node.

In this way, the service can be configured smoothly.

The business is successfully configured and tested by SmartBit to meet the expected criteria.

In this example, the PW ID and PW Label of the T-PW node and S-PW node are assigned as follows: (During the process of establishing PW)

OSN3500 (T-PW, back-end node) OSN7500II (S-PW) OSN3500 (T-PW, back-end node)

PW ID 33 PW ID 333 PW ID 334 PW ID 34

PW Label 30 PW Label 300 PW Label 400 PW Label 40

During the configuration of the S-PW node, the MS-PW process is parameterized as follows:

Front End Back End

PW ID 33 PW ID 34

PW Label 30 PW Label 40

Configure the service according to the above parameters, and the service is configured successfully.

Root Cause

1. According to the prompted error message, the PW ID is duplicated, and it is possible that other services exist on the network element.

2. The service itself has duplicate PW IDs during configuration.

3. In the description of the product documentation, the prerequisites for configuring MS-PW are: configuring the front-end and back-end Tunnel ,configuring the front-end and back-end PW.

However, it is not stated that there is no example of PW ID and PW Label assignment for T-PW and S-PW in the process of PW configuration. According to the PW ID

The error report of Duplicate PW ID occurs when the service is configured according to the principle and correspondence of PW ID and PW Label.

The description in the product documentation is not clear.

Recommendations and Summary

1. It is recommended that the configuration process of the OSN3500 MS-PW be optimized by writing down the details of the

so that the process of business configuration will go smoothly.

2. In the process of learning product knowledge, it is necessary to study the product documentation carefully and dare to think about it.

Whether in the process of business configuration, or maintenance, should have their own thinking, to learn the knowledge thoroughly.

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