Queue Sharing and Redirection
Quality of Service Guide 439
Policers are created and used in a similar manner to queues. The policer ID space is separate from the
queue ID space, allowing both a queue and a policer to share the same ID. The ingress queue-group
template may have up to 32 policers (numbered 1 through 32) and may be defined, while the egress
queue-group template supports a maximum of 8 (numbered 1 through 8). While a policer may be
defined in a queue-group template, it is not actually created until the queue-group template is
instantiated on the ingress context of a forwarding plane or on the egress context of a port.
Once a policer is created, the policer's metering rate and profiling rates may be defined, as well as the
policer's maximum and committed burst sizes (MBS and CBS respectively). Unlike queues that have
dedicated counters, policers allow various stat-mode settings which define the counters that will be
associated with the policer. Another supported feature—packet-byte-offset—provides a policer with
the ability to modify the size of each packet based on a defined number of bytes.
Once a policer is created, it cannot be deleted from the queue-group template unless any forwarding
classes that are redirected to the policer are first removed.
The no version of this command deletes the policer.
Parameters policer-id — The policer-id must be specified when executing the policer command. If the
specified ID already exists, the system enters that policer's context to allow the policer’s
parameters to be modified. If the ID does not exist and is within the allowed range for the QoS
policy type, a context for the policer ID will be created (depending on the system's current
create keyword requirements which may require the create keyword to actually add the new
policer ID to the QoS policy) and the system will enter that new policer’s context for possible
parameter modification.
Values 1 to 32 ingress
1 to 8 egress
fc
Syntax fc fc-name [create]
no fc fc-name
Context config qos>queue-group-templates>egress>queue-group-template
Description The fc command is used to enter the forwarding class mapping context for the given fc-name. Each
forwarding class has a default mapping depending on the egress queue group template. The system
created policer-output-queue template contains queues 1 and 2 by default with queue 1 being best-
effort and queue 2 expedited. Forwarding classes be, l1, af and l2 all map to queue 1 by default.
Forwarding classes h1, ef, h2 and nc all map to queue 2 by default. More queues may be created within
the policer-output-queues template and the default forwarding classes may be changed to any defined
queue within the template.
When all other user defined egress queue group templates are created, only queue 1 (best-effort) exists
and all forwarding classes are mapped to that queue. Other queues may be created and the forwarding
classes may be changed to any defined queue within the template.
To Next Page
Loading...
