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Example: Applying Scheduler Maps and Shaping Rate to DLCIs

This example shows how to apply scheduler maps and shaping rates to individual logical interfaces.


This example uses the following hardware and software components:

  • Junos OS Release 7.4 or later running on router line cards that support Intelligent Queuing (IQ).

  • Junos OS Release 13.2 or later running on MX Series routers containing 16x10GE MPC or MPC3E line cards.

  • Junos OS Release 13.3 or later running on MX Series routers containing MPC4E line cards.

  • Junos OS Release 15.1 or later running on MX Series routers containing MPC6E line cards.


By default, output scheduling is not enabled on logical interfaces. Logical interfaces without shaping configured share a default scheduler. Logical interface scheduling (also called per-unit scheduling) allows you to enable multiple output queues on a logical interface and associate customized scheduling and shaping for each queue.

This example shows how to define schedulers for logical interfaces through the direct use of scheduler maps and shaping rates.

In this example, we associate the scheduler sched-map-logical-0 with logical interface unit 0 on physical interface t3-1/0/0, and allocate 10 Mbps of transmission bandwidth to the logical interface. We also associate the scheduler sched-map-logical-1 with logical interface unit 1 on the same physical interface, t3-1/0/0, and allocate 20 Mbps of transmission bandwidth to the logical interface.

The allocated bandwidth is shared among the individual forwarding classes in the scheduler map. Although these schedulers are configured on a single physical interface, they are independent from each other. Traffic on one logical interface unit does not affect the transmission priority, bandwidth allocation, or drop behavior on the other logical interface unit.

For a similar example, see Example: Applying Scheduling and Shaping to VLANs.


CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.


Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.

  1. Configure the device interfaces.

  2. Define the schedulers.

  3. Define the scheduler maps.

  4. Apply the scheduler maps and shaping rates to the logical interfaces.


From configuration mode, confirm your configuration by entering the show interfaces and show class-of-service commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

If you are done configuring the device, enter commit from configuration mode.