# Configuring Compound Shared Shaping

Compound shared shaping requires that you set a shared-shaping rate in a scheduler profile associated with a best-effort node or queue.

Before you configure compound shared shaping:

- Configure the traffic classes and traffic-class groups.

  See Configuring Traffic Classes That Define Service Levels and Configuring Traffic-Class Groups That Define Service Levels.

To configure compound shared shaping:

1. Create the scheduler profile.
   host1(config)#scheduler-profile compound
2. Configure the compound shared shaper.
   host1(config-scheduler-profile)#shared-shaping-rate 128000 burst 32767 compound explicit-constituents

   The range for the shared-shaping rate is 1000–1000000000 bps (1 Kbps–1000 Kbps); the default is no shaping rate.

   Use the operator and operandValue variables to specify the shared shaping rate as an expression.

   Burst is the catch-up number associated with the shaper; the range is 0–522240 (0–510 KB). Specifying 0 enables the router to select an applicable default value.

   By default, shared shaping is set to auto, where the router selects the type of shared shaping that is configured, depending on the line module. You must specify the compound keyword to actively shape voice and video traffic so that the shared rate cannot be exceeded, and shape data queue rates to the value of the shared rate minus the combined voice and video traffic rate. An error message is generated if you specify compound for line modules that do not support it, and the router applies simple shared shaping.

3. Configure the QoS profile and reference the scheduler profile.
   (config)#qos-profile compound (config-qos-profile)#atm-vc node (config-qos-profile)#atm-vc node group AF (config-qos-profile)#atm-vc node group EF (config-qos-profile)#atm-vc queue traffic-class best-effort scheduler-profile shared-1mbps (config-qos-profile)#exit

   | Tip: The scheduler profile that you configured with the shared-shaping rate must be referenced in the best-effort queue or the best-effort scheduler node.

4. Attach the profile to the interface.
   (config)#interface atm 11/0.10 (config-subif)#qos-profile subscriber-default-mode (config-scheduler-profile)#exit

#### Related Documentation

- Compound Shared Shaping Overview
- Guidelines for Configuring Simple and Compound Shared Shaping
- For more information about specifying an expression that you can reference within a scheduler profile, see Using Expressions for Bandwidth and Burst Values in a Scheduler Profile
- Example: Compound Shared Shaping for ATM VCs
- Constituent Selection for Shared Shaping Overview
- node
- qos-profile
- queue
- scheduler-profile
- shared-shaping-rate
- traffic-class
- traffic-class-group