Configuring Schedulers for Priority Scheduling
This topic describes how to configure priority scheduling.
The priority level can be low, medium-low, medium-high, high, or strict-high. The priorities map to numeric priorities in the underlying hardware. In some cases, different priorities behave similarly, because two software priorities behave differently only if they map to two distinct hardware priorities. For more information, see Platform Support for Priority Scheduling.
Higher-priority queues transmit packets ahead of lower priority queues as long as the higher-priority forwarding classes retain enough bandwidth credit. When you configure a higher-priority queue with a significant fraction of the transmission bandwidth, the queue might lock out (or starve) lower priority traffic.
In the following example procedure, you create a scheduler, configure the mapping between the scheduler and the forwarding class, and assign the scheduler to an interface.
- Configure a scheduler, be-sched, with medium-low priority.[edit]user@host# edit class-of-service schedulers be-scheduser@host# set priority medium-low
- Configure a scheduler map, be-map, that associates be-sched with the best-effort forwarding class.[edit class-of-service]
- Assign the be-map scheduler map to a Gigabit
Ethernet interface, ge-0/0/0.[edit class-of-service]user@host# set interfaces ge-0/0/0 scheduler-map be-map
- Verify your configuration.[edit class-of-service]user@host# show
schedulers { be-sched { priority medium-low; } } scheduler-maps { be-map { forwarding-class best-effort scheduler be-sched; } } ge-0/0/0 { scheduler-map be-map; } - Save your configuration.[edit class-of-service]user@host# commit