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CoS Two-Level Hierarchical Scheduling on MPLS Pseudowire Subscriber Interfaces

Two-level hierarchical scheduling limits the number of hierarchical levels in the scheduling hierarchy to two. In a two-level scheduling hierarchy, all logical interfaces and interface sets share a single level 2 node. Table 1 summarizes the interface hierarchy and the CoS scheduler node levels for two-level hierarchical scheduling.

Table 1: Two-Level Hierarchical Scheduling–Interface Hierarchy Versus Scheduling Nodes

Level 1

Level 2

Level 3

Level 4

Physical interface

Pseudowire transport logical interface

One or more queues

Physical interface

Interface set

One or more queues

Physical interface

Pseudowire service logical interface

One or more queues

You use the two-level hierarchical scheduling when you have many pseudowires but you do not require shaping specific to the subscriber logical interface. For example, when your configuration is one subscriber per pseudowire interface.

Figure 1 shows a two-level hierarchical scheduling configuration for the MPLS pseudowires. In this configuration, level 1 is the physical interface used for the logical tunnel anchor node. All of the pseudowire transport interfaces share a single level 2 node. The level 3 nodes are the pseudowire transport logical interfaces (ps0.0, ps1.0, and ps2.0). In this configuration, interface sets are not configured and only the logical interfaces have traffic control profiles.

Figure 1: MPLS Pseudowire Subscriber Interface Two-Level Scheduler ConfigurationMPLS Pseudowire Subscriber Interface Two-Level Scheduler Configuration

Two-level hierarchical scheduling has up to eight class of service queues. For this configuration, include the maximum-hierarchy-levels 2 option under the [edit interfaces interface-name hierarchical-scheduler] hierarchy level at the physical interface for the anchor logical tunnel.


You cannot configure shaping policies on both the pseudowire logical interfaces and the subscriber logical interfaces over the same pseudowire. If a traffic-control profile is configured on a pseudowire logical interface, and CoS policies are configured on the subscriber logical interface over another pseudowire, all of the logical interfaces are at level 3 and act as peers.