CoS Configuration Overview for MPLS Pseudowire Subscriber Interfaces
CoS supports two-level and three-level hierarchies for MPLS pseudowire subscriber interfaces.
To configure two-level scheduling, include the maximum-hierarchy-levels 2 option under the [edit interfaces interface-name hierarchical-scheduler] statement on the physical interface of the logical tunnel anchor point.
To configure three-level hierarchical scheduling, include the implicit-hierarchy option under the [edit interfaces interface-name hierarchical-scheduler] statement on the physical interface of the logical tunnel anchor point. Use the following guidelines for configuring the implicit-hierarchy option:
If an output traffic-control profile is configured on the pseudowire transport interface and on a pseudowire service interface, the two interfaces form a scheduling hierarchy. The pseudowire transport interface resides in a level 2 scheduler node and the pseudowire service interface resides in a level 3 scheduler node.
If an output traffic-control profile is configured on the pseudowire services interface but not on a pseudowire transport interface, the pseudowire services interface resides in a level 3 scheduler node.
If an output traffic-control profile is only configured on the pseudowire transport interface and not on the pseudowire services interface, the pseudowire transport interface resides in a level 3 scheduler node and all pseudowire traffic uses this node.
If the implicit-hierarchy option is not set on the logical tunnel anchor point, logical interfaces behave normally with the hierarchical-scheduler mode configured with or without the hierarchical-scheduler maximum-hierarchy-levels option under the [edit interfaces interface-name hierarchical-scheduler] statement. In this case, when you apply a traffic-control profile to the pseudowire transport and service logical interfaces, they both reside in level 3 scheduler nodes and do not form a scheduling hierarchy, which might not be the desirable behavior. In business edge, where only the pseudowire logical interfaces need to be shaped, applying the traffic-control profile at just the transport logical interface may be sufficient.
When configuring the logical tunnel physical interface for the maximum hierarchy level, all pseudowire logical interfaces operating on the physical interface use the same hierarchy model. If you want to mix two-level and three-level scheduling hierarchies, you can group the pseudowires together by hierarchy levels and share the same logical tunnel anchor point or you can use three-level scheduling for all pseudowires over the anchor point.
To specify rewrite rules and classifiers on pseudowire interfaces, reference the pseudowire device under the [edit class-of-service interfaces] hierarchy level and specify the rewrite rules and classifiers for the pseudowire interfaces.
To control all pseudowire traffic using the same logical tunnel interface, apply CoS policies at the physical interface for the anchor logical tunnel.
Starting with Junos OS Release 17.3R1, stateful anchor point redundancy support is provided for pseudowire subscriber logical interface by the underlying redundant logical tunnel interface (rlt) in active-backup mode. This redundancy protects the access and the core facing link against anchor PFE (Packet Forwarding Engine) failure. Starting in Junos OS Release 18.1R2, full hierarchical CoS support is provided for stateful anchor point redundancy of pseudowire subscriber logical interfaces. Both transport and services logical interfaces created for the pseudowire subscriber logical interface are stacked on the underlying redundant logical tunnel control logical interface. This logical interface stacking model is used for both redundant and non-redundant pseudowire subscriber logical interfaces. Hierarchical CoS is supported and configured the same on both redundant and non-redundant pseudowire subscriber logical interfaces.