Configuring Congestion Management on a Stack Interface
Pre-configuration Tasks
Configure congestion management on a stack interface when the network intermittently becomes congested. Once congestion management is configured, the sequence at which packets are forwarded is determined according to the defined scheduling policy. High-priority services are scheduled preferentially.
- Perform the stack configuration.
- Configure priority mapping on inbound interface of packets.
Context
After the stack is configured, stack protocol packets and packets between chassis are exchanged on the stack interface. If a large number of packets are exchanged, congestion may occur on the stack interface. As a result, core services such as video services and voice services cannot be processed in a timely manner. You can set the scheduling mode on the stack interface so that services with the same priority are processed in the same manner and services with different priorities are processed based on weights.
Procedure
- Run:
system-viewThe system view is displayed.
- Run:
qos schedule-profile profile-name
A global schedule template is created and the schedule template view is displayed.
- Run:
qos { pq | wrr | drr }
The scheduling mode of a port queue is set to PQ, WRR, or WDRR.
By default, WRR scheduling is used.
- Configure WRR or WDRR weights for port queues.
If the scheduling mode is WRR, run the qos queue queue-index wrr weight weight command to set the WRR weight for a port queue.
By default, the weight in WRR mode is 1.
Perform this step only when the scheduling mode of a port queue is set to PQ+WRR or WRR.
When WRR scheduling is applied and the weight of a queue is set to 0, the queue applies PQ scheduling and other queues apply WRR scheduling. When configuring the PQ+WRR scheduling mode, ensure that the queues with weight 0 (queue using PQ scheduling) are consecutively configured, without being interrupted by the configuration of the queues using WDRR or WRR scheduling.
If the scheduling mode is WDRR, run the qos queue queue-index drr weight weight command to set the WDRR weight for a port queue.
By default, the weight in WDRR mode is 1.Perform this step only when the scheduling mode of a port queue is set to WDRR or PQ+WDRR.
When WDRR scheduling is applied and the weight of a queue is set to 0, the queue applies PQ scheduling and other queues apply WDRR scheduling.
- Run:
quitReturn to the system view.
- Run:
stack-port qos schedule-profile profile-name
The scheduling profile is applied.
