Configuring Simple Shared Shaping

This section explains how to configure the shared shaper by specifying a shared-shaping rate for either the best-effort queue or the best-effort scheduler node for the logical interface. The router locates the other queues associated with the logical interface and shapes that set of queues to the shared rate.

You do not explicitly specify shared shaping on the other queues for the logical interface. You can configure individual shaping rates on the other queues that are less than the shared rate. These individual shapers have the effect of reserving some of the shared bandwidth for the other queues.

Before you configure simple shared shaping:

To configure simple shared shaping:

  1. Create the scheduler profile.
    host1(config)#scheduler-profile shared-1mbps
  2. Configure the shared-shaping rate.
    host1(config-scheduler-profile)#shared-shaping-rate 128000 burst 32767 simple host1(config-scheduler-profile)#shared-shaping-rate 80000 + 53000 host1(config-scheduler-profile)#exit

    The range for the shared-shaping rate is 1–1000000000 bps/Kbps; the default is the minimum shaping rate (1 Kbps). You can set the shaping rate to vary from 1 bps to 1000 Gbps (which is denoted by entering 1000000000 Kbps in the CLI for the shared-shaping-rate command).

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

    Use the bps or kbps keywords to specify the unit of the shaping rate. By default, the shaping rate is configured in bps.

    Use the burst keyword to configure the catch-up number associated with the shaper; the range is 0–522240 (0–510 KB). If you do not specify a burst value, the router selects an applicable default value.

    Use the milliseconds or bytes keywords to specify the unit of the burst size.

    You can specify simple to shape data queue rates to the value of the shared rate minus the combined voice and video traffic rate. By default, shared shaping is set to auto. In this mode, the router selects the type of shared shaping that is applied according to the type of line module. Compound shared shaping is hardware-dependent. If you specify compound for line modules that do not support it, an error message is generated and the router applies simple shared shaping.

    Note: The system processes the shaping rate and shared-shaping rate values that are specified in bps and saves the values in terms of kbps. For example, if you specify the shaping rate as 1010 bps, the system converts the specified integer value as a measure of kbps. In this case, only 1000 bps is configured and the remaining floating point values are truncated because the integer for shaping rate can store only the decimal value. However, if you specify the shaping rate as 1010 kbps, the system correctly saves the specified integer value as 1010 kbps without truncation. Therefore, we recommend that you configure the shaping rate and shared-shaping rate values as rounded values if you specify them in bps.

  3. Configure the QoS profile and reference the scheduler profile.
    host1(config)#qos-profile subscriber-default-mode host1(config-qos-profile)#atm-vc node host1(config-qos-profile)#atm-vc node group AF host1(config-qos-profile)#atm-vc node group EF host1(config-qos-profile)#atm-vc queue traffic-class best-effort scheduler-profile shared-1mbps host1(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.
    host1(config)#interface atm 11/0.10 host1(config-subif)#qos-profile subscriber-default-mode host1(config-scheduler-profile)#exit

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