Service meters for SAP ingress provide an option to use meter resources from the ingress service-meter pool, which provides a larger number of meters/policers for use by access SAPs. This option is available only with table-based classification; it is not available when CAM-based classification is used.
Table-based classification uses meters from either the TCAM pool or the service meter pool, based on the SAP ingress policy type. If the SAP ingress policy is configured to use the use-svc-meter-pool parameter, the policy uses the service meter pool, otherwise the policy uses the TCAM meter pool.
Access to larger numbers of meters/policers from the service-meter pool is useful when there is a need to enforce bandwidth limits for all the FCs and traffic-types (that is, unicast, broadcast, multicast, and unknown-unicast) across a large number of access SAPs. The following functionality is available with the service-meter option:
All access SAPs that use the service-meter pool share a single FC-to-meter-map policy that defines the meter to use for the configured FCs (there is a single configurable policy other than the default FC-to-meter map).
The SAP ingress policy must be configured to use table-based classification with both IP DSCP and dot1p classification policies configured.
SAP ingress policies can be configured with different IP DSCP and dot1p classification policies, which provide flexibility when configuring mappings for IP DSCP and dot1p values to FC for different SAPs.
Even though all access SAPs share the same fc-to-meter-map policy, the meter instances and counter instances are different for each SAP that is configured. This means that each SAP gets an individual instance of meter to enforce rate-limits for traffic that is received on the SAP.
The following usage restrictions apply to meters across FCs and traffic types:
If a meter is mapped to one or more traffic types (unicast, broadcast, multicast, and unknown-unicast) in a specific FC, the meter must be used with the same mapping in other FCs.
Resources are always allocated in chunks of 1, 2, 4, 8, 16, or 32 meters. Counters are allocated in chunks of power of 2.
Service meter is supported for access SAPs that are configured in Epipe, VPLS, IES, and VPRN services. Service meter is not supported for access SAPs that are configured in an RVPLS service.