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 61 shows the scheduler hierarchy built in this configuration.
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 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 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 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.
- To display the traffic-class group, issue the show traffic-class-group command.
- To display the scheduler profile settings for vc-subscriber and 192K, issue the show scheduler-profile command.
- To display the attachments on all QoS profiles, including ipm-adjust, issue the show qos-profile references command.
- To display the settings for the ipm-adjust QoS profile, issue the show qos-profile command.
- To display the settings for the ipm QoS parameter definition, issue the show qos-parameter-define command.
- To display global and interface attachments on the ipm QoS parameter instance, issue the show qos-parameter references command.
- 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.
- 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 traffic-class
fabric
traffic fabric strict
class weight priority
----------- ------ --------
best-effort 8 no
voice 8 no
host1#show traffic-class-group
traffic-class-group EF auto-strict-priority
traffic-class voice
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>
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
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
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
host1#show qos-parameter references
parameter
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
Heirarchical parameter instances: 1
IP multicast parameter instances: 1
Parameter instances reported: 2
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
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 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, Chapter 2, Command-Line Interface.
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 1.1.1.1 255.255.255