Technical Documentation

Managing Excess Bandwidth Distribution for Dynamic CoS

Service providers often used tiered services that must utilize excess bandwidth as traffic patterns vary. By default, excess bandwidth between a configured guaranteed rate and shaping rate is shared equally among all queues with the same excess priority value, which might not be optimal for all subscribers to a service.

This feature is supported for Trio MPC/MIC interfaces on MX Series routers.

To configure parameters to manage excess bandwidth for subscriber interfaces:

  1. Configure the parameters for the interface.
    1. Configure the shaping rate.
      [edit dynamic-profiles profile-name class-of-service traffic-control-profiles profile-name]user@host#set shaping-rate (rate | $junos-cos-shaping-rate)
    2. Configure the excess rate.
      [edit dynamic-profiles profile-name class-of-service traffic-control-profiles profile-name]user@host#set excess-rate (percent percentage | proportion value | percent $junos-cos-excess-rate)
  2. (Optional) Configure parameters for the queue.
    1. Configure the shaping rate.
      [edit dynamic-profiles profile-name class-of-service scheduler scheduler-name]user@host#set shaping-rate (rate | $junos-cos-scheduler-shaping-rate)
    2. Configure the excess rate.
      [edit dynamic-profiles profile-name class-of-service scheduler scheduler-name]user@host#set excess-rate (percent percentage | percent $junos-cos-scheduler-excess-rate)
    3. Configure the excess priority for a queue.
      [edit dynamic-profiles profile-name class-of-service scheduler scheduler-name]user@host#set excess-priority (low | high | $junos-cos-scheduler-excess-priority)

Published: 2010-04-15