Configuring Rate Limits on Nonqueuing Packet Forwarding Engines
On non-queuing Packet Forwarding Engines, rate-limiting is achieved
by shaping the queue to the transmit rate and keeping the queue delay
buffers small to prevent too many packets from being queued once the
shaping rate is reached. To configure rate limits for non-queuing
Packet Forwarding Engines, include the transmit-rate statement
at the [edit class-of-service schedulers scheduler-name] hierarchy level.
Rate limiting is implemented differently on MPCs and Enhanced Queuing DPCs than on non-queuing Packet Forwarding Engines. On MPCs and Enhanced Queuing DPCs, rate-limiting is implemented using a single-rate two-color policer. See Example: Limiting Outbound Traffic Within Your Network by Configuring an Egress Single-Rate Two-Color Policer and Configuring Multifield Classifiers for an example of configuring a single-rate two-color policer to rate limit traffic.
Configuring the Schedulers
The following example configures schedulers, forwarding classes, and a scheduler map for a rate-limited interface.
[edit class-of-service schedulers]
scheduler-1 {
transmit-rate percent 20 rate-limit;
priority high;
}
scheduler-2 {
transmit-rate percent 10 rate-limit;
priority strict-high;
}
scheduler-3 {
transmit-rate percent 40;
priority medium-high;
}
scheduler-4 {
transmit-rate percent 30;
priority medium-high;
}
Configuring the Forwarding Classes
[edit class-of-service]
forwarding-classes {
class cp_000 queue-num 0;
class cp_001 queue-num 1;
class cp_010 queue-num 2;
class cp_011 queue-num 3;
class cp_100 queue-num 4;
class cp_101 queue-num 5;
class cp_110 queue-num 6;
class cp_111 queue-num 7;
}
Configuring the Scheduler Map
[edit class-of-service scheduler-maps]
scheduler-map-1 {
forwarding-class cp_000 scheduler scheduler-1;
forwarding-class cp_001 scheduler scheduler-2;
forwarding-class cp_010 scheduler scheduler-3;
forwarding-class cp_011 scheduler scheduler-4;
}
Applying the Scheduler Map to the Interface
[edit class-of-service interfaces]
ge-1/0/0 {
scheduler-map scheduler-map-1;
}