The user can apply a scheduler policy to the Vport. This allows scheduling control of subscriber tier 1 schedulers in a scheduler policy applied to the egress of a subscriber or SLA profile, or to a PW SAP in an IES or VPRN service. This feature applies only to the 7450 ESS and 7750 SR.
The advantage of using a scheduler policy under a Vport, compared to the use of a port scheduler (with or without an agg-rate rate), is that it allows a port parent to be configured at the Vport level as well as allowing the user to oversubscribe the Ethernet port.
Bandwidth distribution from an egress port scheduler to a Vport configured with a scheduler policy can be performed based on the level/cir-level and weight/cir-weight configured under the scheduler’s port parent. The result is in allowing multiple Vports, for example, representing different DSLAMs, to share the port bandwidth capacity in a flexible way that is under the control of the user.
The configuration of a scheduler policy under a Vport and the configuration of a port scheduler policy or an aggregate rate limit are mutually exclusive.
A scheduler policy is configured under a Vport as follows:
config>port>ethernet>access>egress>vport# scheduler-policy scheduler-policy-name
When using this model, a tier 1 scheduler in a scheduling policy applied to a subscriber profile or SLA profiles must be configured as follows:
config>qos>scheduler-policy>tier# parent-location vport
If the Vport exists, but the port does not have a port scheduler policy applied, then its schedulers are orphaned and no port-level QoS control can be enforced.
The following show/clear commands are available related to the Vport scheduler:
show qos scheduler-hierarchy port port-id vport name
[scheduler scheduler-name] [detail]show qos scheduler-stats port port-id vport name
[scheduler scheduler-name] [detail]clear qos scheduler-stats port port-id vport name
[scheduler scheduler-name] [detail]H-QoS adjustment and host tracking are not supported on schedulers that are configured in a scheduler policy on a Vport, so the configuration of a scheduler policy under a Vport and the configuration of the egress-rate-modify parameter are mutually exclusive.
ESM over MPLS pseudowires are not supported when a scheduler policy is configured on a Vport.