Example: QoS Parameter Configuration for IP Multicast Bandwidth Adjustment

In this example, a QoS administrator configures a QoS parameter definition to associate with the IP multicast bandwidth adjustment application.

The QoS administrator configures the parameter definition to perform the QoS adjustment on an ATM VC subscriber. By specifying the ip-multicast keyword with the qos-parameter-define command, the IP parameter instances are created when the Internet Group Management Protocol (IGMP) joins and leaves.

When you specify a controlled-interface type for atm-vc, the system explicitly creates a parameter instance at the ATM VC with a value that is equal to the sum of the IP adjustments above this interface. This parameter value is referred by a scheduler profile and a QoS profile to create the QoS scheduler hierarchy that adjusts the shared-shaping rate when IGMP joins and leaves.

This subscriber has data, voice, and video service with total subscriber bandwidth of 10 Mbps. Voice traffic is shaped at 192 Kbps and belongs to the strict priority group. Video traffic is provided by the IP multicast bandwidth adjustment application and its rate is configured in the bandwidth map.

Figure 64 shows the scheduler hierarchy built in this configuration.

Figure 64: Scheduler Hierarchy with QoS Adjustment for IP Multicast

Scheduler Hierarchy with QoS Adjustment
for IP Multicast


Configuring Traffic Classes and Traffic-Class Groups

The QoS administrator configures the traffic classes and traffic-class groups for best-effort data and voice services. The QoS administrator does not need to configure a traffic class for the video service because it is transmitted through the IP multicast connection.

  1. Configure the traffic classes.
    1. Configure the traffic class named best-effort.
    2. Configure the traffic class named voice.
      host1(config)#traffic-class voice host1(config-traffic-class)#exit
      host1(config)#traffic-class best-effort host1(config-traffic-class)#exit
  2. Configure a traffic-class group for low-latency expedited forwarding (EF) and add the traffic class for voice service into the traffic-class group EF.
    1. Configure the EF traffic-class group with strict-priority scheduling.
    2. Add the traffic class voice to the traffic-class group.
      host1(config)#traffic-class-group EF auto-strict-priority host1(config-traffic-class-group)#traffic-class voice host1(config-traffic-class-group)#exit

      The remaining traffic class, best-effort, remains in the default traffic-class group.

Configuring the QoS Parameter Definition and Global Parameter Instance

The QoS administrator configures the QoS parameter definition and specifies the IP multicast bandwidth adjustment application. The QoS administrator must configure the parameter as hierarchical.

The QoS scheduler hierarchy is constructed when the subscriber logs on. However, because the parameter instance has not yet been created, the shared-shaping rate is undefined (that is, there is no shaping rate).

Therefore, the QoS administrator creates a global parameter instance to shape the subscriber to the desired bandwidth. The initial value is determined based on the application; in this example, the QoS administrator specifies 0 as the default.

  1. Configure the QoS parameter definition ipm, associate it with the ip-multicast application, and assign it as a hierarchical parameter.
  2. Configure a controlled-interface type of atm-vc.
  3. Configure the global parameter instance.
    host1(config)#qos-parameter-define ipm application ip-multicast hierarchical host1(config-qos-parameter-define)#controlled-interface-type atm-vc host1(config-qos-parameter-define)#exit host1(config)#qos-parameter ipm 0

Therefore, the initial shared-shaping rate is 10 Mbps (10 Mbps - ipm value of 0).

Reference the Parameter Definition Within a Scheduler Profile

The QoS administrator configures the scheduler profile for the ATM VC subscriber and configures the shared-shaping rate. When a scheduler profile references the parameter instance, it enables the IP multicast bandwidth adjustment application to adjust the subscriber bandwidth to account for the video traffic.

The QoS administrator then configures the scheduler profile to shape voice traffic.

  1. Configure the scheduler profile for the ATM VC subscriber.
    1. Configure the scheduler profile named vc-subscriber.
    2. Configure the shared-shaping rate by referencing an expression to limit the subscriber bandwidth to 10 Mbps.
      host1(config)#scheduler-profile vc-subscriber host1(config-scheduler-profile)#shared-shaping-rate 10000000 - ipm burst 50 milliseconds auto host1(config-scheduler-profile)#exit
  2. Configure the scheduler profile for shaping voice traffic.
    1. Configure the scheduler profile named 192K.
    2. Configure the shaping rate at 1920000.
      host1(config)#scheduler-profile 192K host1(config-scheduler-profile)#shaping rate 192000 host1(config-scheduler-profile)#exit

Adding the Scheduler Profiles to a QoS Profile

The IP multicast adjustment application is initialized when IGMP joins or leaves. The QoS administrator specifies the scheduler hierarchy by using a QoS profile rule that refers to a scheduler profile with a parameter expression.

  1. Create the QoS profile named ipm-adjusted.
  2. Configure a queue for ATM VC subinterfaces with the best-effort traffic class.
  3. Configure a queue for ATM VC subinterfaces with the voice traffic class and reference the 192K scheduler profile.
  4. Configure a node for ATM VC subinterfaces and reference the scheduler profile vc-subscriber.
    host1(config)#qos-profile ipm-adjusted host1(config-qos-profile)#atm-vc queue traffic-class best-effort host1(config-qos-profile)#atm-vc queue traffic-class voice scheduler-profile 192k host1(config-qos-profile)#atm-vc node scheduler-profile vc-subscriber host1(config-qos-profile)#exit

Attaching the Parameter Definition to an Interface

The QoS administrator creates a logical interface and attaches the parameter definition. The scheduler hierarchy is created when the QoS administrator creates the interface.

  1. Configure the ATM interface in slot 2, port 0 as a point-to-point ATM interface.
  2. Configure the ATM PVC with aal5snap encapsulation.
  3. Attach the QoS profile vc-subscriber to the subinterface.
  4. Configure the IP address for the ATM subinterface.
    host1(config)#interface atm 2/0 host1(config-if)#interface atm 2/0.1 point-to-point host1(config-subif)#atm pvc 100 0 100 aal5snap host1(config-subif)#qos-profile ipm-adjusted host1(config-subif)#ip address

IP Multicast Bandwidth Adjustment

When an IGMP join occurs, the IP multicast bandwidth adjustment application creates the parameter instance ipm for the IP interface and the ATM VC subinterface. Because the shared-shaping rate of the ATM VC references the ipm parameter, the rate is recalculated. If the imp parameter has a value of 2 Mbps, the resulting shared-shaping rate is 8 Mbps (10 Mbps - 2 = 8 Mbps).

When another IGMP join occurs, the IP multicast bandwidth adjustment application recalculates the value for parameter ipm and configures it to another value (for example, 7 Mbps). The system readjusts the ipm at the ATM VC and readjusts the shared-shaping rate. If the voice traffic is 100 Kbps, then the best-effort traffic is 2.9 Mbps.

When an IGMP leave occurs, the IP multicast bandwidth adjustment application configures the ipm parameter instance with a new value and readjusts the shared-shaping rate.

Monitoring the Configuration

After completing the configuration, the QoS administrator can monitor it by issuing show commands.

  1. To display the traffic classes for best-effort and voice, issue the show traffic-class command.
    host1#show traffic-class
      traffic     fabric    strict
       class      weight   priority
    -----------   ------   --------
    best-effort     8         no
    voice           8         no
  2. To display the traffic-class group, issue the show traffic-class-group command.
    host1#show traffic-class-group
    traffic-class-group EF auto-strict-priority
      traffic-class voice
  3. To display the scheduler profile settings for vc-subscriber and 192K, issue the show scheduler-profile command.
    host1#show scheduler-profile
                    shaping   shaping             strict    assured
      scheduler      rate      burst    weight   priority    rate
    -------------   -------   -------   ------   --------   -------
    default          <none>    <none>     8         no       <none>
    vc-subscriber    <none>    <none>     8         no       <none>
    192k             192000   default     8         no       <none>
                                      shared      shared
                        shared       shaping      shaping         shared
      scheduler      shaping rate     burst     constituent    shaping mode
    -------------   --------------   --------   -----------   ---------------
    default                 <none>     <none>        <none>            <none>
    vc-subscriber   10000000 - ipm   50 bytes        <none>   simple implicit
    192k                    <none>     <none>        <none>            <none>
  4. To display the attachments on all QoS profiles, including ipm-adjust, issue the show qos-profile references command.
    host1#show qos-profile references
              qos profile                              attachment
    --------------------------------  --------------------------------------------
    atm-default                       (qos-port-type-profile)
    serial-default                    (qos-port-type-profile)
    ethernet-default                  (qos-port-type-profile)
    server-default                    (qos-port-type-profile)
    ipm-adjust                        atm-vc ATM2/0.1
      Port attachments:       4
      Interface attachments:  1
      Not attached:           0
  5. To display the settings for the ipm-adjust QoS profile, issue the show qos-profile command.
    host1#show qos-profile ipm-adjust
    qos-profile ipm-adjust:
    t-class interface rule  traffic  scheduler  queue   drop   statistics
    group   type      type  class    profile    profile profile profile
    ------- --------- ----- ----------- ------------- ------- ------- 
            atm-vc    node            vc-subscriber
            atm-vc    queue best-effort default default default default
    EF      atm-vc    queue voice       192k    default default default
  6. To display the settings for the ipm QoS parameter definition, issue the show qos-parameter-define command.
    host1#show qos-parameter-define
                controlled   instance  subscriber
    parameter   interface    interface interface  value
      name        types        types     types    range
    --------- -------------- --------- ---------- ------
    ipm       atm-vc         <none>    <none>     <none>
      name                 properties
    --------- -------------------------------------
    ipm       ip-multicast-adjustment, hierarchical
  7. To display global and interface attachments on the ipm QoS parameter instance, issue the show qos-parameter references command.
    host1#show qos-parameter references
    interface   name     value
    --------- --------- -------
    global    ipm             0
      Global parameter instances:   1
      Parameter instances reported: 1
    host1#show qos-parameter references interface atm 1/0.1
                    parameter         instance
       interface      name    value     Type
    --------------- --------- ----- ------------
    atm-vc ATM1/0.1 ipm         200 hierarchical
    ip ATM1/0.1     ipm         200 ip-multicast
      Explicit parameter instances:      0
      Hierarchical parameter instances:  1
      IP multicast parameter instances:  1
      Parameter instances reported:      2
  8. To display the queue forwarding rates for the ATM VC and IP interfaces on the ATM interface in slot 2, port 0, issue the show egress-queue rates command.
    host1#show egress-queue rates interface atm 2/0.1
                      traffic   forwarded aggregate minimum maximum
       interface       class      rate    drop rate  rate     rate
    --------------- ----------- --------- --------- ------- --------
    atm-vc ATM2/0.1 voice               0         0  192000   192000
    ip ATM2/0.1     best-effort         0         0       0 10000000
      Queues reported:                    2
      Queues filtered (under threshold):  0
    * Queues disabled (no rate period):   0
    **Queues disabled (no resources):     0
      Total queues:                       2
  9. To display the shared shaper settings for the ATM VC on the ATM interface in slot 2, port 0, issue the show qos shared-shaper command.
    host1#show qos shared-shaper interface atm 2/0.1
                                             shaping  shaping     other
       interface            resource           rate    rate       rate 
    --------------- ------------------------ -------- ------- -------------
    atm-vc ATM2/0.1 A atm-vc node            10000000              10000000
                    A atm-vc queue EF voice            192000
     Total shared shapers:          1
     Total constituents:            2
     Total shared shaper failovers: 0
     Compound shared shapers are supported.

Complete Configuration Example

You can use the complete configuration examples provided for each of the configurations in your own network. To customize the configuration example for your needs, copy the text into a text editor, and modify it.

To use the example for immediate use, copy it to the local console or Telnet session from which you access the router.

You can also save the example as a script (.scr) file that executes the commands as though they were entered at the terminal. For information about executing .scr files, see JunosE System Basics Configuration Guide.

From Global Configuration mode:

! Create the voice traffic class. traffic-class voice exit traffic-class best-effort exit traffic-class-group EF auto-strict-priority traffic-class best-effort exit ! Create the ipm QoS parameter definition. qos-parameter-define ipm application ip-multicast hierarchical controlled-interface-type atm-vc exit ! Create a global parameter instance of the ipm QoS parameter. qos-parameter ipm 0 ! Configure the vc-subscriber and 192K scheduler profiles. scheduler-profile vc-subscriber shared-shaping-rate 10000000 - ipm burst 50 milliseconds auto exit scheduler-profile 192K shaping-rate 192000 exit ! Add the scheduler profiles to the ipm-adjusted QoS profile. qos-profile ipm-adjusted atm-vc queue traffic-class best-effort atm-vc queue traffic-class voice scheduler-profile 192k atm-vc node scheduler-profile vc-subscriber exit ! Attach the parameter definition to an interface. interface atm 2/0.1 point-to-point atm pvc 100 0 100 aal5snap qos-profile ipm-adjusted ip address 255.255.255

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