Hierarchical CoS on MPLS Pseudowire Subscriber Interfaces Overview

Junos OS supports two aspects of CoS for MPLS pseudowire subscriber interfaces. You can apply CoS rewrite rules and behavior aggregate (BA) classifiers to MPLS pseudowire subscriber interfaces. In addition, CoS performs egress hierarchical shaping towards the subscriber on MPLS pseudowire subscriber interfaces.

Hierarchical CoS enables you to apply traffic scheduling and queuing parameters and packet transmission scheduling parameters to an individual subscriber interface rather than to all interfaces configured on the port. Hierarchical CoS is supported on MX Series routers with either EQ DPCs or MPC/MICs installed.

On Juniper Networks MX Series routers, MPC/MIC and EQ DPC interfaces support a four-level CoS scheduling hierarchy that, when fully configured, consists of the physical interface (level 1), the interface set or the underlying interface (level 2), one or more logical interfaces (level 3), and one or more queues (level 4). Although all CoS scheduling hierarchies are four-level, level 1 is always the physical interface and level 4 is always the queue. Hierarchical scheduling configurations consist of the type of interfaces you configure; for example, a logical interface or an interface set and where those interfaces reside in the scheduling hierarchy, either level 2 or level 3. Because many hierarchical scheduling configurations are possible, we use the terms two-level hierarchical scheduling and three-level hierarchical scheduling in this discussion.