The service is interrupted when the outgoing port queue Shaping is enabled on the N1EMS4 single board.

Products

OptiX OSN3500

OptiX OSN 3500 II

Failure Category

RPR

Ethernet Failure

Phenomenon Description

The specifics of the EVPL service for the shared VCTRUNK of NE2 and NE3 are shown in Figure 1.

Figure 1 Configuration of EVPL service for shared VCTRUNK

2 pairs of customers ( D and D',E and E ') share 300M bandwidth of VCTRUNK1.

Streams are created at PORT1 and PORT2 respectively and the stream type is Port Stream.

Create a CoS of type " simple " and schedule the port flow of PORT1 to queue 1 of VCTRUNK1 and the port flow of PORT2 to queue 3 of VCTRUNK1.

Enable traffic shaping for the 3rd queue of VCTRUNK1 and configure the CIR to be 300M bit/s.

Enable traffic shaping for queue 1 of VCTRUNK1, using the default Shaping configuration parameters.

If the traffic into PORT2 reaches 300M bit/s at this time, the service interruption for PORT1 is found. So even if there is remaining bandwidth, it cannot be allocated to queue 1.

Cause Analysis

The possible causes are:

In this case, queue 3 of VCTRUNK1 has a higher priority than queue 1. The messages from the high priority queue 3 grab all the possible bandwidth ( 300M ) so that there is no residual bandwidth to allocate to the low priority queue 1, resulting in the interruption of D and D' services.

Queue 1 has only enabled Shaping without configuring Shaping bandwidth, and the default Shaping bandwidth is 0, so it will break service.

Procedure

Possible Cause 1: Messages from high-priority queue 3 have seized all possible bandwidth.

Turn down the bandwidth of the high-priority queue appropriately.

Right-click on the network element icon in the main view and select "Network Element Manager".

Select the corresponding Ethernet board in the navigation tree, and select "Configuration > Qos Management > Port Shaping Management" in the function tree.

Set the committed bandwidth and burst size (less than 300M ).

Possible cause 2: Shaping is enabled on queue 1 without configuring the committed bandwidth ( CIR ) for shaping.

Configure the Shaping bandwidth for queue 1.

Right-click on the network element icon in the main view and select "Network Element Manager".

Select the corresponding Ethernet board in the navigation tree, and select "Configuration > Qos Management > Port Shaping Management" in the function tree.

Select Queue 1 and configure the parameters.

Reference

Similar issue: One of the possible reasons for service interruption after binding CAR to a flow is that the CAR is enabled, but the CIR and PIR of the CAR are not configured (default is 0 ), so the service is interrupted.