Technical Documentation

Configuring CoS Features on Shared Interfaces

With class-of-service (CoS) features:

  • Random early detection (RED) drop profiles and scheduler maps that are bound to physical shared interfaces must be configured on the RSD.
  • Classifiers and rewrite rules that are bound to logical shared interfaces must be configured on the PSD.
  • Tricolor marking policers must be configured on the PSD.
  • CoS queues and forwarding classes must be configured identically on both the RSD and on the PSD that owns the logical shared interfaces.

For example, the following CoS forwarding classes need to be configured on both the RSD and the PSD:

class-of-service {forwarding-classes {queue 0 be priority high;queue 1 ef priority high;queue 2 af priority high;queue 3 nc priority high;queue 4 fc4 priority high;queue 5 fc5 priority high;queue 6 fc6 priority high;queue 7 fc7 priority high;}}

To view queue statistics on a shared interface, you must issue the show interfaces queue so-fpc/pic/slot command or the show interfaces queue ge-fpc/pic/slot command on the RSD. If you issue the command on the PSD, the system displays this message: “Egress queue statistics are not applicable to this interface.”

For more information about CoS features, see the JUNOS Class of Service Configuration Guide.


Published: 2010-04-12