Technical Documentation
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 1 shows the scheduler hierarchy built in this configuration.
Figure 1: 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.
- Configure the traffic classes.
- Configure the traffic class named best-effort.
- 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
- 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.
- Configure the EF traffic-class group with strict-priority scheduling.
- 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.
- Configure the QoS parameter definition ipm, associate it with the ip-multicast application, and assign it as a hierarchical parameter.
- Configure a controlled-interface type of atm-vc.
- 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.
- Configure the scheduler profile for the ATM VC subscriber.
- Configure the scheduler profile named vc-subscriber.
- 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
- Configure the scheduler profile for shaping voice traffic.
- Configure the scheduler profile named 192K.
- 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.
- Create the QoS profile named ipm-adjusted.
- Configure a queue for ATM VC subinterfaces with the best-effort traffic class.
- Configure a queue for ATM VC subinterfaces with the voice traffic class and reference the 192K scheduler profile.
- 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.
- Configure the ATM interface in slot 2, port 0 as a point-to-point ATM interface.
- Configure the ATM PVC with aal5snap encapsulation.
- Attach the QoS profile vc-subscriber to the subinterface.
- 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 1.1.1.1 255.255.255.0
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.
- To display the traffic classes for best-effort and voice,
issue the show traffic-class command.
host1#show traffic-class fabric traffic fabric strict class weight priority ----------- ------ -------- best-effort 8 no voice 8 no - 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
- 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> - 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 ATM2/0.1Port attachments: 4 Interface attachments: 1 Not attached: 0
- 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 - 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>parameter name properties --------- ------------------------------------- ipm ip-multicast-adjustment, hierarchical
- To display global and interface attachments on the ipm
QoS parameter instance, issue the show qos-parameter
references command.
host1#show qos-parameter references parameter interface name value --------- --------- ------- global ipm 0Global 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-multicastExplicit parameter instances: 0 Heirarchical parameter instances: 1 IP multicast parameter instances: 1 Parameter instances reported: 2
- 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 10000000Queues reported: 2 Queues filtered (under threshold): 0 * Queues disabled (no rate period): 0 **Queues disabled (no resources): 0 Total queues: 2
- 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 shared shaping shaping interface resource rate rate other --------------- ------------------------ -------- ------- ------------- atm-vc ATM2/0.1 A atm-vc node 10000000 rate 10000000 A atm-vc queue EF voice 192000Total 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:
