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    Example: Compound Shared Shaping for ATM VCs

    Figure 1 illustrates a typical DSL triple-play configuration, involving voice, video, and data traffic. In this example, a total of 1 Mbps of bandwidth is allocated to voice, video, and best-effort data traffic associated with the VC 1 logical interface.

    The voice queue in the EF traffic-class group for VC 1 is a strict constituent that has first claim on up to 200 Kbps of the shared bandwidth. The video queue in the AF traffic-class group is a strict constituent that can claim up to 300 Kbps of the remaining 800–1000 Kbps of shared bandwidth. The best-effort queue for logical interface VC 1 is a strict constituent that has the last claim to the remaining 500–1000 Kbps of shared bandwidth.

    Figure 1: VC Compound Shared Shaping Example

    VC Compound Shared Shaping Example

    To configure VC compound shared shaping:

    1. Configure the traffic classes, traffic-class groups, and additional scheduler profiles.
    2. Configure the scheduler profile that defines the shared shaper and the profiles that apply the legacy shaper.
      host1(config)#scheduler-profile shared-1Mbps host1(config-scheduler-profile)#shared-shaping-rate 1000000 burst 32768 auto host1(config)#scheduler-profile 300Kbps host1(config-scheduler-profile)#shaping-rate 300000 host1(config)#scheduler-profile 200Kbps host1(config-scheduler-profile)#shaping-rate 200000
    3. Configure the QoS profile.
      host1(config)#qos-profile vcSharedShaping
    4. Create group nodes.
      host1(config-qos-profile)#atm group AF scheduler-profile default host1(config-qos-profile)#atm group EF scheduler-profile default
    5. Create VC nodes for each group and for traffic in the default group.
      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
    6. Create queues for the best-effort, video, and voice traffic. Apply the scheduler profile that defines the shared-shaping rate to the best-effort queue. Apply the legacy shaper profiles to the voice and video traffic queues.
      host1(config-qos-profile)#atm-vc queue traffic-class best-effort scheduler-profile shared-1mbps host1(config-qos-profile)#atm-vc queue traffic-class video scheduler-profile 300Kbps host1(config-qos-profile)#atm-vc queue traffic-class voice scheduler-profile 200Kbps host1(config-qos-profile)#exit
    7. Attach the QoS profile to an ATM subinterface.
      host1(config)#interface atm 11/0.1 host1(config-interface)#qos-profile vcSharedShaping host1(config-interface)#exit

    In this example, the constituents of the VC shared shaper are the VC 1 best effort node, the VC 1 Group EF node, and the VC 1 Group AF node. The available bandwidth is strictly allocated in the following order:

    1. VC 1 EF group node
    2. VC 1 AF group node
    3. VC 1 best effort node

    To display the sample shared shaper configuration:

    host1# show shared-shaper atm 11/0.1
                     shared  current
                     shaping shaping                           shaping
       interface      rate    rate           resource           rate
    ---------------- ------- ------- ------------------------- -------
    atm-vc ATM11/0.1 1000000 compound best-effort atm-vc queue       
                                      atm-vc best-effort node        
                                      EF voice atm-vc queue     200000
                                      AF video atm-vc queue     300000
    atm-vc ATM11/0.2 1000000 compound best-effort atm-vc queue       
                                      atm-vc best-effort node        
                                      EF voice atm-vc queue     200000
                                      AF video atm-vc queue     300000
     Total shared shapers: 2
     Total constituents:   8
     Total failovers:      0
    

    Published: 2014-08-11