QoS: Congestion Management Configuration Guide Cisco IOS Release 12.2SY

Bias-Free Language

The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.

Book Contents
Find Matches in This Book
Available Languages
Download Options

Book Title

QoS: Congestion Management Configuration Guide Cisco IOS Release 12.2SY

Chapter Title

Configuring Weighted Fair Queueing

Results

Updated:
July 20, 2011

Chapter: Configuring Weighted Fair Queueing

Configuring Weighted Fair Queueing

Last Updated: July 20, 2011

Feature History

Release

Modification

Cisco IOS

For information about feature support in Cisco IOS software, use Cisco Feature Navigator.

This module describes the tasks for configuring flow-based weighted fair queueing (WFQ), distributed WFQ (DWFQ), and class-based WFQ (CBWFQ), and distributed class-based WFQ (DCBWFQ) and the related features described in the following section, which provide strict priority queueing (PQ) within WFQ or CBWFQ:

  • IP RTP Priority Queueing
  • Frame Relay IP RTP Priority Queueing
  • Frame Relay PVC Interface Priority Queueing
  • Low Latency Queueing
  • Distributed Low Latency Queueing
  • Low Latency Queueing (LLQ) for Frame Relay
  • Burst Size in Low Latency Queueing
  • Per-VC Hold Queue Support for ATM Adapters

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Flow-Based Weighted Fair Queueing Configuration Task List

WFQ provides traffic priority management that automatically sorts among individual traffic streams without requiring that you first define access lists. WFQ can also manage duplex data streams such as those between pairs of applications, and simplex data streams such as voice or video. There are two categories of WFQ sessions: high bandwidth and low bandwidth. Low-bandwidth traffic has effective priority over high-bandwidth traffic, and high-bandwidth traffic shares the transmission service proportionally according to assigned weights.

When WFQ is enabled for an interface, new messages for high-bandwidth traffic streams are discarded after the configured or default congestive messages threshold has been met. However, low-bandwidth conversations, which include control message conversations, continue to enqueue data. As a result, the fair queue may occasionally contain more messages than its configured threshold number specifies.

With standard WFQ, packets are classified by flow. Packets with the same source IP address, destination IP address, source TCP or User Datagram Protocol (UDP) port, or destination TCP or UDP port belong to the same flow. WFQ allocates an equal share of the bandwidth to each flow. Flow-based WFQ is also called fair queueing because all flows are equally weighted.

The Cisco IOS software provides two forms of flow-based WFQ:

  • Standard WFQ, which is enabled by default on all serial interfaces that run at 2 Mbps or below, and can run on all Cisco serial interfaces.
  • Distributed WFQ, which runs only on Cisco 7000 series routers with a Route Switch Processor (RSP)-based RSP7000 interface processor or Cisco 7500 series routers with a Versatile Interface Processor (VIP)-based VIP2-40 or greater interface processor. (A VIP2-50 interface processor is strongly recommended when the aggregate line rate of the port adapters on the VIP is greater than DS3. A VIP2-50 interface processor is required for OC-3 rates.) .

Flow-based WFQ uses a traffic data stream discrimination registry service to determine to which traffic stream a message belongs. Refer to the table accompanying the description of the fair-queue (WFQ) command in the Cisco IOS Quality of Service Solutions Command Reference for the attributes of a message that are used to classify traffic into data streams.

Defaults are provided for the congestion threshold after which messages for high-bandwidth conversations are dropped, and for the number of dynamic and reservable queues; however, you can fine-tune your network operation by changing these defaults. Refer to the tables accompanying the description of the fair-queue (WFQ) command in the Cisco IOS Quality of Service Solutions Command Reference for the default number of dynamic queues that WFQ and CBWFQ use when they are enabled on an interface or ATM VC. These values do not apply for DWFQ.


Note
WFQ is the default queueing mode on interfaces that run at E1 speeds (2.048 Mbps) or below. It is enabled by default for physical interfaces that do not use Link Access Procedure, Balanced (LAPB), X.25, or Synchronous Data Link Control (SDLC) encapsulations. WFQ is not an option for these protocols. WFQ is also enabled by default on interfaces configured for Multilink PPP (MLP). However, if custom queueing (CQ) or priority queueing (PQ) is enabled for a qualifying link, it overrides fair queueing, effectively disabling it. Additionally, WFQ is automatically disabled if you enable autonomous or silicon switching.

If you enable flow-based DWFQ and then enable class-based DWFQ (either QoS-group based or ToS-based), class-based DWFQ will replace flow-based DWFQ.

If you enable class-based DWFQ and then want to switch to flow-based DWFQ, you must disable class-based DWFQ using the no fair-queue class-based command before enabling flow-based DWFQ.

If you enable one type of class-based DWFQ and then enable the other type, the second type will replace the first.

DWFQ runs only on Cisco 7000 series routers with an RSP-based RSP7000 interface processor or Cisco 7500 series routers with a VIP-based VIP2-40 or greater interface processor. (A VIP2-50 interface processor is strongly recommended when the aggregate line rate of the port adapters on the VIP is greater than DS3. A VIP2-50 interface processor is required for OC-3 rates.)

DWFQ can be configured on interfaces but not subinterfaces. It is not supported on Fast EtherChannel, tunnel, or other logical or virtual interfaces such as MLP.

For flow-based DWFQ, packets are classified by flow. Packets with the same source IP address, destination IP address, source TCP or UDP port, destination TCP or UDP port, and protocol belong to the same flow.

To configure flow-based WFQ, perform the tasks described in the following sections.

Flow-based WFQ is supported on unavailable bit rate (UBR), variable bit rate (VBR), and available bit rate (ABR) ATM connections.

Configuring WFQ

Command

Purpose

 
Router(config-if)# fair-queue [congestive-discard-threshold [dynamic-queues [reservable-queues]]]

Configures an interface to use WFQ.

Monitoring Fair Queueing

Command

Purpose

 
Router# show interfaces [interface]

Displays statistical information specific to an interface.

 
Router# show queue  interface-type interface-number

Displays the contents of packets inside a queue for a particular interface or virtual circuit (VC).

 
Router# show queueing fair

Displays status of the fair queueing configuration.

Distributed Weighted Fair Queueing Configuration Task List

To configure DWFQ, perform one of the mutually exclusive tasks described in the following sections:

Configuring Flow-Based DWFQ

SUMMARY STEPS

1.    Router(config-if)# fair-queue

2.    Router(config-if)# fair-queue aggregate-limit aggregate-packet

3.    Router(config-if)# fair-queue individual-limit individual-packet


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config-if)# fair-queue 

Enables flow-based DWFQ.

 
Step 2
Router(config-if)# fair-queue aggregate-limit aggregate-packet 

(Optional) Sets the total number of buffered packets before some packets may be dropped. Below this limit, packets will not be dropped.

Note    In general, you should not change the aggregate, individual, or class limit value from the default. Use the fair-queue aggregate-limit, fair-queue individual-limit, and fair-queue limit commands only if you have determined that you would benefit from using different values, based on your particular situation.
 
Step 3
Router(config-if)# fair-queue individual-limit individual-packet 

(Optional) Sets the maximum queue size for individual per-flow queues during periods of congestion.

 

Configuring QoS-Group-Based DWFQ

SUMMARY STEPS

1.    Router(config-if)# fair-queue qos-group

2.    Router(config-if)# fair-queue qos-group number weight weight

3.    Router(config-if)# fair-queue aggregate-limit aggregate-packet

4.    Router(config-if)# fair-queue individual-limit individual-packet

5.    Router(config-if)# fair-queue qos-group number limit class-packet


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config-if)# fair-queue qos-group 

Enables QoS-group-based DWFQ.

 
Step 2
Router(config-if)# fair-queue qos-group number weight weight 

For each QoS group, specifies the percentage of the bandwidth to be allocated to each class.

 
Step 3
Router(config-if)# fair-queue aggregate-limit aggregate-packet 

(Optional) Sets the total number of buffered packets before some packets may be dropped. Below this limit, packets will not be dropped.

Note    In general, you should not change the aggregate, individual, or class limit value from the default. Use the fair-queue aggregate-limit, fair-queue individual-limit, and fair-queue limit commands only if you have determined that you would benefit from using different values, based on your particular situation.
 
Step 4
Router(config-if)# fair-queue individual-limit individual-packet 

(Optional) Sets the maximum queue size for every per-flow queue during periods of congestion.

 
Step 5
Router(config-if)# fair-queue qos-group number limit class-packet 

(Optional) Sets the maximum queue size for a specific QoS group queue during periods of congestion.

 

Configuring Type of Service-Based DWFQ

SUMMARY STEPS

1.    Router(config-if)# fair-queue tos

2.    Router(config-if)# fair-queue tos number weight weight

3.    Router(config-if)# fair-queue aggregate-limit aggregate-packet

4.    Router(config-if)# fair-queue individual-limit individual-packet

5.    Router(config-if)# fair-queue tos number limit class-packet


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config-if)# fair-queue tos 

Enables ToS-based DWFQ

 
Step 2
Router(config-if)# fair-queue tos number weight weight 

(Optional) For each ToS class, specifies the percentage of the bandwidth to be allocated to each class.

 
Step 3
Router(config-if)# fair-queue aggregate-limit aggregate-packet 

(Optional) Sets the total number of buffered packets before some packets may be dropped. Below this limit, packets will not be dropped.

Note    In general, you should not change the aggregate, individual, or class limit value from the default. Use the fair-queue aggregate-limit, fair-queue individual-limit, and fair-queue limitcommands only if you have determined that you would benefit from using different values, based on your particular situation.
 
Step 4
Router(config-if)# fair-queue individual-limit individual-packet 

(Optional) Sets the maximum queue size for every per-flow queue during periods of congestion.

 
Step 5
Router(config-if)# fair-queue tos number limit class-packet 

(Optional) Sets the maximum queue size for a specific ToS queue during periods of congestion.

 

Monitoring DWFQ

Command

Purpose

 
Router# show interfaces [interface]

Displays the statistical information specific to an interface.

 
Router# show queueing fair-queue

Displays status of the fair queueing configuration.

Class-Based Weighted Fair Queueing Configuration Task List

CBWFQ is supported on VBR and ABR ATM connections. It is not supported on UBR connections.

Defining Class Maps

SUMMARY STEPS

1.    Router(config)# class-map class-map-name

2.   Do one of the following:

  • Router(config-cmap)# match access-group {access-group|name access-group-name}


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# class-map class-map-name  

Specifies the name of the class map to be created.

 
Step 2
Do one of the following:
  • Router(config-cmap)# match access-group {access-group|name access-group-name}


Example:

Router(config-cmap)# match input-interface interface-name



Example:



Example:



Example:



Example:

Router(config-cmap)# match protocol protocol



Example:



Example:



Example:



Example:



Example:

Router(config-cmap)# match mpls experimental number

 

Specifies the name of the access control list (ACL) against whose contents packets are checked to determine if they belong to the class. CBWFQ supports numbered and named ACLs.

Specifies the name of the input interface used as a match criterion against which packets are checked to determine if they belong to the class.

Specifies the name of the protocol used as a match criterion against which packets are checked to determine if they belong to the class.

Specifies the value of the EXP field to be used as a match criterion against which packets are checked to determine if they belong to the class.

Note    Other match criteria can be used when defining class maps. For additional match criteria, see "Applying QoS Features Using the MQC" module.
 

Configuring Class Policy in the Policy Map

To configure a policy map and create class policies that make up the service policy, use the policy-map command to specify the policy map name, then use one or more of the following commands to configure policy for a standard class or the default class:

  • class
  • bandwidth (policy-map class)
  • fair-queue (for class-default class only)
  • queue-limit or random-detect

For each class that you define, you can use one or more of the listed commands to configure class policy. For example, you might specify bandwidth for one class and both bandwidth and queue limit for another class.

The default class of the policy map (commonly known as the class-default class) is the class to which traffic is directed if that traffic does not satisfy the match criteria of other classes whose policy is defined in the policy map.

You can configure class policies for as many classes as are defined on the router, up to the maximum of 64. However, the total amount of bandwidth allocated for all classes included in a policy map must not exceed 75 percent of the available bandwidth on the interface. The other 25 percent is used for control and routing traffic. (To override the 75 percent limitation, use the max-reserved bandwidth command.) If not all of the bandwidth is allocated, the remaining bandwidth is proportionally allocated among the classes, based on their configured bandwidth.

The class-default class is used to classify traffic that does not fall into one of the defined classes. Once a packet is classified, all of the standard mechanisms that can be used to differentiate service among the classes apply. The class-default class was predefined when you created the policy map, but you must configure it. If no default class is configured, then by default the traffic that does not match any of the configured classes is flow classified and given best-effort treatment.

To configure class policies in a policy map, perform the optional tasks described in the following sections. If you do not perform the steps in these sections, the default actions are used.

Configuring Class Policy Using Tail Drop

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-name

3.    Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent}

4.    Router(config-pmap-c)# queue-limit number-of-packets


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map 

Specifies the name of the policy map to be created or modified.

 
Step 2
Router(config-pmap)# class class-name 

Specifies the name of a class to be created and included in the service policy.

Note    To configure policy for more than one class in the same policy map, repeat Step 2 through Step 4 . Note that because this set of commands uses the queue-limit command, the policy map uses tail drop, not Weighted Random Early Detection (WRED) packet drop.
 
Step 3
Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent} 

Specifies the amount of bandwidth, in kbps, or percentage of available bandwidth, to be assigned to the class. The amount of bandwidth configured should be large enough to also accommodate Layer 2 overhead.

 
Step 4
Router(config-pmap-c)# queue-limit number-of-packets 

Specifies the maximum number of packets that can be queued for the class.

 

Configuring Class Policy Using WRED Packet Drop

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-name

3.    Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent}

4.    Router(config-pmap-c)# random-detect

5.   Do one of the following:

  • Router(config-pmap-c)# random-detect exponential-weighting-constant exponent


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map 

Specifies the name of the policy map to be created or modified.

 
Step 2
Router(config-pmap)# class class-name 

Specifies the name of a class to be created and included in the service policy.

Note    To configure policy for more than one class in the same policy map, repeat Step 2 through Step 5 . Note that this set of commands uses WRED packet drop, not tail drop.
 
Step 3
Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent} 

Specifies the amount of bandwidth, in kbps, or percentage of available bandwidth to be assigned to the class. The amount of bandwidth configured should be large enough to also accommodate Layer 2 overhead.

 
Step 4
Router(config-pmap-c)# random-detect 

Enables WRED. The class policy will drop packets using WRED instead of tail drop.

Note    If you configure a class in a policy map to use WRED for packet drop instead of tail drop, you must ensure that WRED is not configured on the interface to which you intend to attach that service policy.
 
Step 5
Do one of the following:
  • Router(config-pmap-c)# random-detect exponential-weighting-constant exponent


Example:

Router(config-pmap-c)# random-detect precedence precedence min-threshold max-threshold mark-prob-denominator

 

Configures the exponential weight factor used in calculating the average queue length.

Configures WRED parameters for packets with a specific IP precedence. Repeat this command for each precedence.

 

Configuring the Class-Default Class Policy

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-default default-class-name

3.   Do one of the following:

  • Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent}

4.    Router(config-pmap-c)# queue-limit number-of-packets


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map  

Specifies the name of the policy map to be created or modified.

 
Step 2
Router(config-pmap)# class class-default default-class-name  

Specifies the default class so that you can configure or modify its policy.

 
Step 3
Do one of the following:
  • Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent}


Example:

Router(config-pmap-c)# fair-queue [number-of-dynamic-queues]

 

Specifies the amount of bandwidth, in kbps, or percentage of available bandwidth to be assigned to the class. The amount of bandwidth configured should be large enough to also accommodate Layer 2 overhead.

Specifies the number of dynamic queues to be reserved for use by flow-based WFQ running on the default class. The number of dynamic queues is derived from the bandwidth of the interface. Refer to the tables accompanying the description of the fair-queue (WFQ) command in the Cisco IOS Quality of Service Solutions Command Reference for the default number of dynamic queues that WFQ and CBWFQ use when they are enabled on an interface or ATM VC.

 
Step 4
Router(config-pmap-c)# queue-limit number-of-packets  

Specifies the maximum number of packets that the queue for the default class can accumulate.

 

Configuring the Class-Default Class Policy

To configure a policy map and configure the class-default class to use WRED packet drop, use the first command in global configuration mode to specify the policy map name, then to configure policy for the default class use the following commands in policy-map class configuration mode:

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-default default-class-name

3.   Do one of the following:

  • Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent}

4.    Router(config-pmap-c)# random-detect

5.   Do one of the following:

  • Router(config-pmap-c)# random-detect exponential-weighting-constant exponent


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map  

Specifies the name of the policy map to be created or modified.

 
Step 2
Router(config-pmap)# class class-default default-class-name  

Specifies the default class so that you can configure or modify its policy.

 
Step 3
Do one of the following:
  • Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent}


Example:

Router(config-pmap-c)# fair-queue [number-of-dynamic-queues]

 

Specifies the amount of bandwidth, in kbps, or percentage of available bandwidth to be assigned to the class. The amount of bandwidth configured should be large enough to also accommodate Layer 2 overhead.

Specifies the number of dynamic queues to be reserved for use by flow-based WFQ running on the default class The number of dynamic queues is derived from the bandwidth of the interface. Refer to the tables accompanying the description of the fair-queue (WFQ) command in the Cisco IOS Quality of Service Solutions Command Reference for the default number of dynamic queues that WFQ and CBWFQ use when they are enabled on an interface or ATM VC.

 
Step 4
Router(config-pmap-c)# random-detect  

Enables WRED. The class policy will drop packets using WRED instead of tail drop.

 
Step 5
Do one of the following:
  • Router(config-pmap-c)# random-detect exponential-weighting-constant exponent


Example:

Router(config-pmap-c)# random-detect precedence precedence min-threshold max-threshold mark-prob-denominator

 

Configures the exponential weight factor used in calculating the average queue length.

Configures WRED parameters for packets with a specific IP precedence. Repeat this command for each precedence.

 

Attaching the Service Policy and Enabling CBWFQ

Command

Purpose

 
Router(config-if)# service-policy output  policy-map

Enables CBWFQ and attaches the specified service policy map to the output interface.

Note    Configuring CBWFQ on a physical interface is only possible if the interface is in the default queueing mode. Serial interfaces at E1 (2.048 Mbps) and below use WFQ by default--other interfaces use FIFO by default. Enabling CBWFQ on a physical interface overrides the default interface queueing method. Enabling CBWFQ on an ATM permanent virtual circuit (PVC) does not override the default queueing method.

Modifying the Bandwidth for an Existing Policy Map Class

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-name

3.    Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent}


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map 

Specifies the name of the policy map containing the class to be modified.

 
Step 2
Router(config-pmap)# class class-name 

Specifies the name of a class whose bandwidth you want to modify.

 
Step 3
Router(config-pmap-c)# bandwidth{bandwidth-kbps | percent percent} 

Specifies the new amount of bandwidth, in kbps, or percentage of available bandwidth to be used to reconfigure the class. The amount of bandwidth configured should be large enough to also accommodate Layer 2 overhead.

 

Modifying the Queue Limit for an Existing Policy Map Class

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-name

3.    Router(config-pmap-c)# queue-limit number-of-packets


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map 

Specifies the name of the policy map containing the class to be modified.

 
Step 2
Router(config-pmap)# class class-name 

Specifies the name of a class whose queue limit you want to modify.

 
Step 3
Router(config-pmap-c)# queue-limit number-of-packets 

Specifies the new maximum number of packets that can be queued for the class to be reconfigured. The default and maximum number of packets is 64.

 

Deleting Class Maps From Service Policy Maps

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# no class class-name

3.    Router(config-pmap-c)# no class class-default


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map 

Specifies the name of the policy map containing the classes to be deleted.

 
Step 2
Router(config-pmap)# no class class-name 

Specifies the name of the classes to be deleted.

 
Step 3
Router(config-pmap-c)# no class class-default 

Deletes the default class.

 

Deleting Policy Maps

Command

Purpose

 
Router(config)# no policy-map  policy-map

Specifies the name of the policy map to be deleted.

Verifying Configuration of Policy Maps and Their Classes

Command

Purpose

 
Router# show policy-map  policy-map

Displays the configuration of all classes that make up the specified policy map.

 
Router# show policy-map  policy-map  class  class-name

Displays the configuration of the specified class of the specified policy map.

 
Router# show policy-map interface  interface-name

Displays the configuration of all classes configured for all policy maps on the specified interface.

Note    The counters displayed after issuing the show policy-map interface command are updated only if congestion is present on the interface. 
Router# show queue  interface-type interface-number

Displays queueing configuration and statistics for a particular interface.

Distributed Class-Based Weighted Fair Queueing Configuration Task List

To configure DCBWFQ, perform the tasks described in the following sections. Although all the tasks are listed as optional, you must complete the task in either the first or second section.

DCBWFQ is configured using user-defined traffic classes and service policies. Traffic classes and service policies are configured using the Modular Quality of Service Command-Line Interface (CLI) feature.

Modifying the Bandwidth for an Existing Traffic Class

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-name

3.    Router(config-pmap-c)# bandwidth bandwidth-kbps


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map  

Specifies the name of the traffic policy to be created or modified.

 
Step 2
Router(config-pmap)# class class-name

Example:

 

Specifies the name of a traffic class whose bandwidth you want to modify.

 
Step 3
Router(config-pmap-c)# bandwidth bandwidth-kbps  

Specifies the amount of allocated bandwidth, in kbps, to be reserved for the traffic class in congested network environments.

Note    After configuring the traffic policy with the policy-map command, you must still attach the traffic policy to an interface before it is successfully enabled. For information on attaching a traffic policy to an interface, see the "Applying QoS Features Using the MQC" module.
 

Modifying the Queue Limit for an Existing Traffic Class

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# classclass-name

3.    Router(config-pmap-c)# queue-limit number-of-packets


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map  

Specifies the name of the traffic policy to be created or modified.

 
Step 2
Router(config-pmap)# classclass-name  

Specifies the name of a traffic class whose queue limit you want to modify.

 
Step 3
Router(config-pmap-c)# queue-limit number-of-packets  

Specifies the new maximum number of packets that can be queued for the traffic class to be reconfigured. The default and maximum number of packets is 64.

Note    After configuring the service policy with the policy-map command, you must still attach the traffic policy to an interface before it is successfully enabled. For information on attaching a traffic policy to an interface, see the "Applying QoS Features Using the MQC" module.
 

Monitoring and Maintaining DCBWFQ

Command

Purpose

 
Router#
 
show policy-map

Displays all configured traffic policies.

 
Router#
 show policy-map  policy-map-name

Displays the user-specified traffic policy.

 
Router#
 
show policy-map interface

Displays statistics and configurations of all input and output policies attached to an interface.

 
Router#
 show policy-map interface interface-spec

Displays configuration and statistics of the input and output policies attached to a particular interface.

 
Router#
 show policy-map interface  interface-spec input

Displays configuration and statistics of the input policy attached to an interface.

 
Router#
 show policy-map interface  interface-spec output

Displays configuration statistics of the output policy attached to an interface.

 
Router#
 show policy-map [interface  interface-spec 
[
input 
| 
output
]
 [class class-name]]]]

Displays the configuration and statistics for the class name configured in the policy.

IP RTP Priority Configuration Task List

Frame Relay Traffic Shaping (FRTS) and Frame Relay Fragmentation (FRF.12 or higher) must be configured before the Frame Relay IP RTP Priority feature is used.

Configuring IP RTP Priority

Command

Purpose

 
Router(config-if)# ip rtp priority  starting-rtp-port-number port-number-range bandwidth

Reserves a strict priority queue for a set of RTP packet flows belonging to a range of UDP destination ports.

Note    The ip rtp reserve and ip rtp priority commands cannot be configured on the same interface.
Caution   

Because the ip rtp priority command gives absolute priority over other traffic, it should be used with care. In the event of congestion, if the traffic exceeds the configured bandwidth, then all the excess traffic is dropped.

Verifying IP RTP Priority

Command

Purpose

 
Router# show queue  interface-type interface-number

Displays queueing configuration and statistics for a particular interface.

Monitoring and Maintaining IP RTP Priority

Command

Purpose

 
Router# debug priority

Displays priority queueing output if packets are dropped from the priority queue.

 
Router# show queue  interface-type interface-number

Displays queueing configuration and statistics for a particular interface.

Frame Relay IP RTP Priority Configuration Task List

Configuring Frame Relay IP RTP Priority

Command

Purpose

 
Router(config-map-class)# frame-relay ip rtp priority  starting-rtp-port-number port-number-range bandwidth

Reserves a strict priority queue for a set of RTP packet flows belonging to a range of UDP destination ports.

Note    Because the frame-relay ip rtp priority command gives absolute priority over other traffic, it should be used with care. In the event of congestion, if the traffic exceeds the configured bandwidth, then all the excess traffic is dropped.

Verifying Frame Relay IP RTP Priority

Command

Purpose

 
Router# show frame relay pvc

Displays statistics about PVCs for Frame Relay interfaces.

 
Router# show queue interface-type interface-number

Displays fair queueing configuration and statistics for a particular interface.

 
Router# show traffic-shape queue

Displays information about the elements queued at a particular time at the VC data-link connection identifier (DLCI) level.

Monitoring and Maintaining Frame Relay IP RTP Priority

Command

Purpose

 
Router# debug priority

Displays priority queueing output if packets are dropped from the priority queue.

Frame Relay PVC Interface Priority Configuration Task List

Configuring PVC Priority in a Map Class

SUMMARY STEPS

1.    Router(config)# map-class frame-relay map-class-name

2.    Router(config-map-class)# frame-relay interface-queue priority{high| medium| normal| low}


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# map-class frame-relay map-class-name 

Specifies a Frame Relay map class.

 
Step 2
Router(config-map-class)# frame-relay interface-queue priority{high| medium| normal| low} 

Assigns a PVC priority level to a Frame Relay map class.

 

Enabling Frame Relay PIPQ and Setting Queue Limits

SUMMARY STEPS

1.    Router(config)# interface type number [name-tag]

2.    Router(config-if)# encapsulation frame-relay[cisco | ietf]

3.    Router(config-if)# frame-relay interface-queue priority [high-limit medium-limit normal-limit low-limit]


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# interface type number [name-tag] 

Configures an interface type and enters interface configuration mode.

 
Step 2
Router(config-if)# encapsulation frame-relay[cisco | ietf] 

Enables Frame Relay encapsulation.

 
Step 3
Router(config-if)# frame-relay interface-queue priority [high-limit medium-limit normal-limit low-limit] 

Enables Frame Relay PIPQ and sets the priority queue limits.

 

Assigning a Map Class to a PVC

SUMMARY STEPS

1.    Router(config-if)# frame-relay interface-dlci dlci

2.    Router(config-fr-dlci)# class map-class-name


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config-if)# frame-relay interface-dlci dlci 

Specifies a single PVC on a Frame Relay interface.

 
Step 2
Router(config-fr-dlci)# class map-class-name 

Associates a map class with a specified PVC.

 

Verifying Frame Relay PIPQ

Command

Purpose

 
Router# show frame-relay pvc [interface  interface][dlci]

Displays statistics about PVCs for Frame Relay interfaces.

 
Router# show interfaces [type number][first][last]

Displays the statistical information specific to a serial interface.

 
Router# show queueing [custom | fair | priority | random-detect [interface atm_subinterface [vc [[vpi/] vci]]]]

Lists all or selected configured queueing strategies.

Monitoring and Maintaining Frame Relay PIPQ

Command

Purpose

 
Router# debug priority

Displays priority queueing output if packets are dropped from the priority queue.

 
Router# show frame-relay pvc [interface  interface][dlci]

Displays statistics about PVCs for Frame Relay interfaces.

 
Router# show interfaces [type number][first][last]

Displays the statistical information specific to a serial interface.

 
Router# show queue  interface-name interface-number [vc [vpi/] vci][queue-number]

Displays the contents of packets inside a queue for a particular interface or VC.

 
Router# show queueing [custom | fair | priority | random-detect [interface atm_subinterface [vc [[vpi/] vci]]]]

Lists all or selected configured queueing strategies.

Low Latency Queueing Configuration Task List

Configuring LLQ

Command

Purpose

 
Router(config-pmap-c)# priority bandwidth

Reserves a strict priority queue for this class of traffic.

Verifying LLQ

Command

Purpose

 
Router# show queue  interface-type interface-number

Displays queueing configuration and statistics for a particular interface.

Monitoring and Maintaining LLQ

Command

Purpose

 
Router# debug priority

Displays priority queueing output if packets are dropped from the priority queue.

 
Router# show queue  interface-type interface-number

Displays queueing configuration and statistics for a particular interface.

 
Router# show policy-map interface interface-name

Displays the configuration of all classes configured for all traffic policies on the specified interface. Displays if packets and bytes were discarded or dropped for the priority class in the traffic policy attached to the interface.

Distributed LLQ Configuration Task List

Configuring a Priority Queue for an Amount of Available Bandwidth

SUMMARY STEPS

1.    Router(config)# policy-map policy-name

2.    Router(config-pmap)# class class-name

3.    Router(config-pmap-c)# priority kpbs [bytes


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-name  

Specifies the name of the policy map to configure. Enters policy-map configuration mode.

 
Step 2
Router(config-pmap)# class class-name  

Specifies the name of a predefined class included in the service policy. Enters policy-map class configuration mode.

 
Step 3
Router(config-pmap-c)# priority kpbs [bytes  

Reserves a priority queue with a specified amount of available bandwidth for CBWFQ traffic.

Note    The traffic policy configured in this section is not yet attached to an interface. For information on attaching a traffic policy to an interface, see the "Applying QoS Features Using the MQC" module.
 

Configuring a Priority Queue for a Percentage of Available Bandwidth

SUMMARY STEPS

1.    Router(config)# policy-map policy-name

2.    Router(config-pmap)# classclass-name

3.    Router(config-pmap-c)# priority percent percent


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-name

Example:

 

Specifies the name of the traffic policy to configure. Enters policy-map configuration mode.

 
Step 2
Router(config-pmap)# classclass-name

Example:

 

Specifies the name of a predefined class included in the service policy. Enters policy-map class configuration mode.

 
Step 3
Router(config-pmap-c)# priority percent percent

Example:

 

Reserves a priority queue with a specified percentage of available bandwidth for CBWFQ traffic.

Note    The traffic policy configured in this section is not yet attached to an interface. For information on attaching a traffic policy to an interface, see the "Applying QoS Features Using the MQC" module.
 

Configuring a Transmission Ring Limit on an ATM PVC

SUMMARY STEPS

1.    Router(config)# interface atm interface-name

2.    Router(config-if)# atm pvc vcd-number vpi-number vci-number Encapsulation-type tx-ring-limit ring-limit


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# interface atm interface-name 

Specifies the name of the ATM interface to configure.

 
Step 2
Router(config-if)# atm pvc vcd-number vpi-number vci-number Encapsulation-type tx-ring-limit ring-limit 

Specifies the ATM PVC to configure, the encapsulation type, and the transmission ring limit value.

 

Configuring a Transmission Ring Limit on an ATM Subinterface

SUMMARY STEPS

1.    Router(config)# interface atm subinterface name

2.    Router(config-subif)# pvc pvc-name

3.    Router(config-if-atm-vc)# tx-ring-limit ring-limit


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# interface atm subinterface name 

Specifies the name of the subinterface to configure.

 
Step 2
Router(config-subif)# pvc pvc-name 

Specifies the name of the PVC to configure.

 
Step 3
Router(config-if-atm-vc)# tx-ring-limit ring-limit 

Specifies the transmission ring limit value.

 

Verifying Distributed LLQ

Command

Purpose

 
Router# show interfaces [interface-type interface-number] fair-queue

Displays information and statistics about WFQ for a VIP-based interface.

 
Router# show policy-map  policy-map-name

Displays the contents of a policy map, including the priority setting in a specific policy map.

Verifying a Transmission Ring Limit

Command

Purpose

 
Router# show atm vc  vc-name

Displays the contents of a VC. The show atm vc command output will indicate the transmission ring limit value if the tx-ring-limit command is successfully enabled.

Monitoring and Maintaining Distributed LLQ

Command

Purpose

 
Router# show interfaces [interface-type interface-number] fair-queue

Displays information and statistics about WFQ for a VIP-based interface.

 
Router# show policy-map  policy-map-name

Displays the contents of a traffic policy, including the priority setting in a specific policy map.

 
Router# show policy interface interface-name

Displays the configuration of all classes configured for all service policies on the specified interface. Displays if packets and bytes were discarded or dropped for the priority class in the service policy attached to the interface.

 
Router# show atm vc  vc-name

Displays the contents of a VC. The show atm vc command output will indicate the transmission ring limit value if the tx-ring-limit command is successfully enabled.

Low Latency Queueing for Frame Relay Configuration Task List

Defining Class Maps

SUMMARY STEPS

1.    Router(config)# class-mapclass-map-name

2.   Do one of the following:

  • Router(config-cmap)# match access-group {a ccess-group| name access-group-name}


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# class-mapclass-map-name 

Specifies the name of the class map to be created.

 
Step 2
Do one of the following:
  • Router(config-cmap)# match access-group {a ccess-group| name access-group-name}


Example:

Router(config-cmap)# match input-interface interface-name



Example:



Example:



Example:



Example:



Example:

Router(config-cmap)# match protocol protocol



Example:

 

Specifies the name of the ACL against whose contents packets are checked to determine if they belong to the class.

Specifies the name of the input interface used as a match criterion against which packets are checked to determine if they belong to the class.

Specifies the name of the protocol used as a match criterion against which packets are checked to determine if they belong to the class.

 

Configuring Class Policy in the Policy Map

To configure a policy map and create class policies that make up the service policy, begin with the policy-map command to specify the policy map name. Then use one or more of the following commands to configure the policy for a standard class or the default class:

  • priority
  • bandwidth
  • queue-limit or random-detect
  • fair-queue (for class-default class only)

For each class that you define, you can use one or more of the commands listed to configure the class policy. For example, you might specify bandwidth for one class and both bandwidth and queue limit for another class.

The default class of the policy map (commonly known as the class-default class) is the class to which traffic is directed if that traffic does not satisfy the match criteria of the other classes defined in the policy map.

The class-default class is used to classify traffic that does not fall into one of the defined classes. Even though the class-default class is predefined when you create the policy map, you still have to configure it. If a default class is not configured, then traffic that does not match any of the configured classes is given best-effort treatment, which means that the network will deliver the traffic if it can, without any assurance of reliability, delay prevention, or throughput.

You can configure class policies for as many classes as are defined on the router, up to the maximum of 64. However, the total amount of bandwidth allocated for all classes in a policy map must not exceed the minimum committed information rate (CIR) configured for the VC minus any bandwidth reserved by the frame-relay voice bandwidth and frame-relay ip rtp priority commands. If the minimum CIR is not configured, the bandwidth defaults to one half of the CIR. If all of the bandwidth is not allocated, the remaining bandwidth is allocated proportionally among the classes on the basis of their configured bandwidth.

To configure class policies in a policy map, perform the tasks described in the following sections.

Configuring Class Policy for a LLQ Priority Queue

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-name

3.    Router(config-pmap-c)# priority bandwidth-kbps


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map 

Specifies the name of the policy map to be created or modified.

 
Step 2
Router(config-pmap)# class class-name 

Specifies the name of a class to be created and included in the service policy.

 
Step 3
Router(config-pmap-c)# priority bandwidth-kbps 

Creates a strict priority class and specifies the amount of bandwidth, in kbps, to be assigned to the class.

 

Configuring Class Policy Using a Specified Bandwidth and WRED Packet Drop

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-name

3.    Router(config-pmap-c)# bandwidth bandwidth-kbps

4.    Router(config-pmap-c)# random-detect


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map 

Specifies the name of the policy map to be created or modified.

 
Step 2
Router(config-pmap)# class class-name 

Specifies the name of a class to be created and included in the service policy.

 
Step 3
Router(config-pmap-c)# bandwidth bandwidth-kbps 

Specifies the amount of bandwidth to be assigned to the class, in kbps, or as a percentage of the available bandwidth. Bandwidth must be specified in kbps or as a percentage consistently across classes. (Bandwidth of the priority queue must be specified in kbps.)

 
Step 4
Router(config-pmap-c)# random-detect 

Enables WRED.

 

Configuring the Class-Default Class Policy

SUMMARY STEPS

1.    Router(config)# policy-map policy-map

2.    Router(config-pmap)# class class-default default-class-name

3.   Do one of the following:

  • Router(config-pmap-c)# bandwidth bandwidth-kbps

4.    Router(config-pmap-c)# queue-limit number-of-packets


DETAILED STEPS
  Command or Action Purpose
Step 1
Router(config)# policy-map policy-map 

Specifies the name of the policy map to be created or modified.

 
Step 2
Router(config-pmap)# class class-default default-class-name 

Specifies the default class so that you can configure or modify its policy.

 
Step 3
Do one of the following:
  • Router(config-pmap-c)# bandwidth bandwidth-kbps


Example:

Router(config-pmap-c)# fair-queue [number-of-dynamic-queues]

 

Specifies the amount of bandwidth, in kbps, to be assigned to the class.

Specifies the number of dynamic queues to be reserved for use by flow-based WFQ running on the default class. The number of dynamic queues is derived from the bandwidth of the interface.

 
Step 4
Router(config-pmap-c)# queue-limit number-of-packets 

Specifies the maximum number of packets that the queue for the default class can accumulate.

 

Attaching the Service Policy and Enabling LLQ for Frame Relay

Command

Purpose

 
Router(config-map-class)# service-policy output  policy-map

Attaches the specified service policy map to the output interface and enables LLQ for Frame Relay.

Note    When LLQ is enabled, all classes configured as part of the service policy map are installed in the fair queueing system.

Verifying Configuration of Policy Maps and Their Classes

Command

Purpose

 
Router# show frame-relay pvc  dlci

Displays statistics about the PVC and the configuration of classes for the policy map on the specified DLCI.

 
Router# show policy-map interface  interface-name

When FRTS is configured, displays the configuration of classes for all Frame Relay VC-level policy maps.

When FRTS is not configured, displays the configuration of classes for the interface-level policy.

 
Router# show policy-map interface   interface-name   dlci  dlci

When FRTS is configured, displays the configuration of classes for the policy map on the specified DLCI.

Monitoring and Maintaining LLQ for Frame Relay

For a list of commands that can be used to monitor LLQ for Frame Relay, see the previous section "Verifying Configuration of Policy Maps and Their Classes."

Configuring Burst Size in LLQ Configuration Task List

Configuring the LLQ Bandwidth

Command

Purpose

 
Router(config)# priority  bandwidth

Specifies the maximum amount of bandwidth, in kpbs, for the priority traffic.

Configuring the LLQ Burst Size

Command

Purpose

 
Router(config)# priority  bandwidth burst

Specifies the burst size in bytes. The range is from 32 to 2 million.

Verifying the LLQ Burst Size

Command

Purpose

 
Router# show policy-map

Displays the configuration of all classes comprising the specified service policy map or all classes for all existing policy maps.

 
Router# show policy-map interface
 		 
           
 Displays the configuration of classes configured for service polices on the specified interface or PVC.
 		 
         
 
         
       
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Per-VC Hold Queue Support for ATM Adapters Configuration Task List
 
    
 
    
 
    
 
      
     
 
     
 
    
 
    
 
      
       
     
Configuring the per-VC Hold Queue on an ATM Adapter
 
     
 
      
 
        
         
       
 
         
         
 
           
 Command
 		 
           
 Purpose
 		 
         
 
         
         
         
 
           
Router(config)# vc-hold-queue number-of-packets
 		 
           
 Specifies the number of packets contained in the per-VC hold queue. This can be a number from 5 to 1024.
 		 
         
 
         
       
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Verifying the Configuration of the per-VC Hold Queue on an ATM Adapter
 
     
 
      
 
        
         
       
 
         
         
 
           
 Command
 		 
           
 Purpose
 		 
         
 
         
         
         
 
           
Router# show queueing interface
 		 
           
 Displays the queueing statistics of an interface or VC.
 		 
         
 
         
       
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Examples Flow-Based WFQ Configuration
 
    
 
     
 
       
        
      
 The following example requests a fair queue with a congestive discard threshold of 64 messages, 512 dynamic queues, and 18 RSVP queues:
 
      
Router(config)# interface Serial 3/0
Router(config-if)# ip unnumbered Ethernet 0/
0
Router(config-if)# fair-queue 64 512 18

 
     
 
    
 
    
 
     
 
     
 
    
 
   
 
   
 
     
      
    
Examples DWFQ Configuration
 
    
 
     
 
       
        
     
 
    
 
    
 
      
     
 
     
 
    
 
    
 
      
       
     
Example Flow-Based DWFQ
 
     
 
      
 
        
         
       
 The following example enables DWFQ on the HSSI interface 0/0/0:
 
       
Router(config)# interface Hssi0/0/0
Router(config-if)# description 45Mbps to R2
Router(config-if)# ip address 200.200.14.250 255.255.255.252
Router(config-if)# fair-queue

 
       
 The following is sample output from the show interfaces fair-queue command for this configuration:
 
       
Router# show interfaces hssi 0/0/0 fair-queue
Hssi0/0/0 queue size 0
     packets output 35, drops 0
WFQ: global queue limit 401, local queue limit 200

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example QoS-Group-Based DWFQ
 
     
 
      
 
        
         
       
 The following example configures QoS-group-based DWFQ. Committed access rate (CAR) policies are used to assign packets with an IP Precedence value of 2 to QoS group 2, and packets with an IP Precedence value of 6 are assigned to QoS group 6.
 
       
Router(config)# interface Hssi0/0/0
Router(config-if)# ip address 188.1.3.70 255.255.255.0
Router(config-if)# rate-limit output access-group rate-limit 6 155000000 2000000 8000000 conform-action set-qos-transmit 6 exceed-action drop
Router(config-if)# rate-limit output access-group rate-limit 2 155000000 2000000 8000000 conform-action set-qos-transmit 2 exceed-action drop
Router(config-if)# fair-queue qos-group
Router(config-if)# fair-queue qos-group 2 weight 10
Router(config-if)# fair-queue qos-group 2 limit 27
Router(config-if)# fair-queue qos-group 6 weight 30
Router(config-if)# fair-queue qos-group 6 limit 27
!
Router(config)# access-list rate-limit 2 2
Router(config)# access-list rate-limit 6 6

 
       
 The following sample output shows how to view WFQ statistics using the show interfaces fair-queue command: 
 
       
Router# show interfaces fair-queue
 Hssi0/0/0 queue size 0
        packets output 806232, drops 1
 WFQ: aggregate queue limit 54, individual queue limit 27
    max available buffers 54
 
     Class 0: weight 60 limit 27 qsize 0 packets output 654 drops 0
     Class 2: weight 10 limit 27 qsize 0 packets output 402789 drops 0
     Class 6: weight 30 limit 27 qsize 0 packets output 402789 drops 1
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example ToS-Based DWFQ
 
     
 
      
 
        
         
       
 The following example configures type of service (ToS)-based DWFQ using the default parameters:
 
       
Router# configure terminal
Router(config)# interface Hssi0/0/0
Router(config-if)# fair-queue tos
Router(config-if)# end

 
       
 The following is output of the show running-config command for the HSSI interface 0/0/0. Notice that the router automatically adds the default weights and limits for the ToS classes to the configuration.
 
       
interface Hssi0/0/0
 ip address 188.1.3.70 255.255.255.0
 fair-queue tos
 fair-queue tos 1 weight 20
 fair-queue tos 1 limit 27
 fair-queue tos 2 weight 30
 fair-queue tos 2 limit 27
 fair-queue tos 3 weight 40
 fair-queue tos 3 limit 27

 
       
 The following sample output shows how to view DWFQ statistics using the show interfaces fair-queue command:
 
       
Router# show interfaces fair-queue
 Hssi0/0/0 queue size 0
        packets output 1417079, drops 2
 WFQ: aggregate queue limit 54, individual queue limit 27
    max available buffers 54
 
     Class 0: weight 10 limit 27 qsize 0 packets output 1150 drops 0
     Class 1: weight 20 limit 27 qsize 0 packets output 0 drops 0
     Class 2: weight 30 limit 27 qsize 0 packets output 775482 drops 1
     Class 3: weight 40 limit 27 qsize 0 packets output 0 drops 0
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Examples CBWFQ Configuration
 
    
 
     
 
       
        
     
 
    
 
    
 
      
     
 
     
 
    
 
    
 
      
       
     
Example Class Map Configuration
 
     
 
      
 
        
         
       
 In the following example, ACLs 101 and 102 are created. Next, two class maps are created and their match criteria are defined. For the first map class, called class1, the numbered ACL 101 is used as the match criterion. For the second map class, called class2, the numbered ACL 102 is used as the match criterion. Packets are checked against the contents of these ACLs to determine if they belong to the class. 
 
       
Router(config)# access-list 101 permit udp host 10.10.10.10 host 10.10.10.20 range 16384 20000
Router(config# access-list 102 permit udp host 10.10.10.10 host 10.10.10.20 range 53000 56000
Router(config)# class-map class1
Router(config-cmap)# match access-group 101
Router(config-cmap)# exit
Router(config-cmap)# class-map class2
Router(config-cmap)# match access-group 102
Router(config-cmap)# exit

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Policy Creation
 
     
 
      
 
        
         
       
 In the following example, a policy map called policy1 is defined to contain policy specification for the two classes, class1 and class2. The match criteria for these classes were defined in the previous "Example Class Map Configuration" section.
 
       
 For class1, the policy specifies the bandwidth allocation request and the maximum number of packets that the queue for this class can accumulate. For class2, the policy specifies only the bandwidth allocation request, so the default queue limit of 64 packets is assumed. 
 
       
Router(config)# policy-map policy1
Router(config-pmap)# class class1
Router(config-pmap-c)# bandwidth 3000
 
Router(config-pmap-c)# queue-limit 30
Router(config-pmap-c)# exit
Router(config-pmap)# class class2
Router(config-pmap-c)# bandwidth 2000
 
Router(config-pmap-c)# exit

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Policy Attachment to Interfaces
 
     
 
      
 
        
         
       
 The following example shows how to attach an existing policy map. After you define a policy map, you can attach it to one or more interfaces to specify the service policy for those interfaces. Although you can assign the same policy map to multiple interfaces, each interface can have only one policy map attached at the input and one policy map attached at the output.
 
       
 The policy map in this example was defined in the previous section, "Example Policy Creation."
 
       
Router(config)# interface e1/1
Router(config-if)# service output policy1
 
Router(config-if)# exit
Router(config)# interface fa1/0/0
Router(config-if)# service output policy1
 
Router(config-if)# exit

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example CBWFQ Using WRED Packet Drop
 
     
 
      
 
        
         
       
 In the following example, the class map called class1 is created and defined to use the input FastEthernet interface 0/1 as a match criterion to determine if packets belong to the class. Next, the policy map policy1 is defined to contain policy specification for class1, which is configured for WRED packet drop.
 
       
Router(config)# class-map class1
Router(config-cmap)# match input-interface FastEthernet0/1
!
Router(config)# policy-map policy1
Router(config-pmap)# class class1
Router(config-pmap-c)# bandwidth 1000
Router(config-pmap-c)# random-detect
!
Router(config)# interface serial0/0
Router(config-if)# service-policy output policy1
!
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Examples Display Service Policy Map Content
 
     
 
      
 
        
         
       
 The following examples show how to display the contents of service policy maps. Four methods can be used to display the contents. 
 
      
 
     
 
     
 
       
      
 
      
 
     
 
     
 
       
        
      
All Classes for a Specified Service Policy Map
 
      
 
       
 The following example displays the contents of the service policy map called pol1:
 
       
Router# show policy-map po1
Policy Map po1
 Weighted Fair Queueing
    Class class1
       Bandwidth 937 (kbps) Max thresh 64 (packets)
    Class class2
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class3
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class4
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class5
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class6
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class7
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class8
         Bandwidth 937 (kbps)  Max thresh 64 (packets)
 
      
 
      
 
       
 
       
 
      
 
     
 
     
 
       
        
      
All Classes for All Service Policy Maps
 
      
 
       
 The following example displays the contents of all policy maps on the router:
 
       
Router# show policy-map
 
Policy Map poH1
 Weighted Fair Queueing
    Class class1
       Bandwidth 937 (kbps) Max thresh 64 (packets)
    Class class2
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class3
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class4
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class5
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class6
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class7
        Bandwidth 937 (kbps)  Max thresh 64 (packets)
    Class class8
         Bandwidth 937 (kbps)  Max thresh 64 (packets)
Policy Map policy2
 Weighted Fair Queueing
    Class class1
       Bandwidth 300 (kbps) Max thresh 64 (packets)
    Class class2
        Bandwidth 300  (kbps)  Max thresh 64 (packets)
    Class class3
        Bandwidth 300 (kbps)  Max thresh 64 (packets)
    Class class4
        Bandwidth 300 (kbps)  Max thresh 64 (packets)
    Class class5
        Bandwidth 300 (kbps)  Max thresh 64 (packets)
    Class class6
        Bandwidth 300 (kbps)  Max thresh 64 (packets)  
 
      
 
      
 
       
 
       
 
      
 
     
 
     
 
       
        
      
Specified Class for a Service Policy Map
 
      
 
       
 The following example displays configurations for the class called class7 that belongs to the policy map called po1:
 
       
Router# show policy-map po1 class class7


Class class7
 Bandwidth 937 (kbps) Max Thresh 64 (packets)
 
      
 
      
 
       
 
       
 
      
 
     
 
     
 
       
        
      
All Classes for All Service Policy Maps on a Specified Interface
 
      
 
       
 The following example displays configurations for classes on the output Ethernet interface 2/0. The numbers shown in parentheses are for use with the Management Information Base (MIB).
 
       
Router# show policy-map interface
 e2/0
Ethernet2/0 
  Service-policy output:p1 (1057)
    Class-map:c1 (match-all) (1059/2)
      19 packets, 1140 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match:ip precedence 0  (1063)
      Weighted Fair Queueing
        Output Queue:Conversation 265 
        Bandwidth 10 (%) Max Threshold 64 (packets)
        (pkts matched/bytes matched) 0/0
        (depth/total drops/no-buffer drops) 0/0/0
    Class-map:c2 (match-all) (1067/3)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match:ip precedence 1  (1071)
      Weighted Fair Queueing
        Output Queue:Conversation 266 
        Bandwidth 10 (%) Max Threshold 64 (packets)
        (pkts matched/bytes matched) 0/0
        (depth/total drops/no-buffer drops) 0/0/0
 
   Class-map:class-default (match-any) (1075/0)
      8 packets, 2620 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match:any  (1079)
 
      
 
      
 
       
 
       
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Examples Distributed CBWFQ Configuration
 
    
 
     
 
       
        
     
 
    
 
    
 
      
     
 
     
 
    
 
    
 
      
       
     
Example Traffic Class Configuration
 
     
 
      
 
        
         
       
 In the following example, two traffic classes are created and their match criteria are defined. For the first traffic class, called class1, the numbered ACL 101 is used as the match criterion. For the second traffic class, called class2, the numbered ACL 102 is used as the match criterion. Packets are checked against the contents of these ACLs to determine if they belong to the traffic class. 
 
       
Router(config)# class-map class1

Router(config-cmap)# match access-group 101
Router(config-cmap)# exit
Router(config)# class-map class2

Router(config-cmap)# match access-group 102
Router(config-cmap)# exit

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Traffic Policy Creation
 
     
 
      
 
        
         
       
 In the following example, a traffic policy called policy1 is defined to associate QoS features with the two traffic classes, class1 and class2. The match criteria for these traffic classes were defined in the previous "Example Class Map Configuration" section.
 
       
 For class1, the QoS policies include bandwidth allocation request and maximum packet count limit for the queue reserved for the traffic class. For class2, the policy specifies only a bandwidth allocation request, so the default queue limit of 64 packets is assumed. 
 
       
Router(config)# policy-map policy1
Router(config-pmap)# class class1
Router(config-pmap-c)# bandwidth 3000 
Router(config-pmap-c)# queue-limit 30
Router(config-pmap)# exit
Router(config-pmap)# class class2
Router(config-pmap-c)# bandwidth 2000 
Router(config-pmap)# exit

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Traffic Policy Attachment to an Interface
 
     
 
      
 
        
         
       
 The following example shows how to attach an existing traffic policy to an interface. After you define a traffic policy, you can attach it to one or more interfaces to specify a traffic policy for those interfaces. Although you can assign the same traffic policy to multiple interfaces, each interface can have only one traffic policy attached at the input and one policy map attached at the output at one time.
 
       
Router(config)# interface fe1/0/0

Router(config-if)# service output policy1
 
Router(config-if)# exit

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Examples IP RTP Priority Configuration
 
    
 
     
 
       
        
     
 
    
 
    
 
      
     
 
     
 
    
 
    
 
      
       
     
Example CBWFQ Configuration
 
     
 
      
 
        
         
       
 The following example first defines a CBWFQ configuration and then reserves a strict priority queue:
 
       
! The following commands define a class map:
Router(config)# class-map class1
Router(config-cmap)# match access-group 101
Router(config-cmap)# exit
! The following commands create and attach a policy map:
Router(config)# policy-map policy1
Router(config-pmap)# class class1
Router(config-pmap-c)# bandwidth 3000
Router(config-pmap-c)# queue-limit 30
Router(config-pmap-c)# random-detect
Router(config-pmap-c)# random-detect precedence 0 32 256 100
Router(config-pmap-c)# exit
Router(config)# interface Serial1
Router(config-if)# service-policy output policy1
! The following command reserves a strict priority queue:
Router(config-if)# ip rtp priority 16384 16383 40

 
       
 The queue-limitand random-detectcommands are optional commands for CBWFQ configurations. The queue-limitcommand is used for configuring tail drop limits for a class queue. The random-detectcommand is used for configuring RED drop limits for a class queue, similar to the random-detect command available on an interface.
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Virtual Template Configuration
 
     
 
      
 
        
         
       
 The following example configures a strict priority queue in a virtual template configuration with CBWFQ. 
 
       
Router(config)# multilink virtual-template 1
Router(config)# interface virtual-template 1
Router(config-if)# ip address 172.16.1.1 255.255.255.0
Router(config-if)# no ip directed-broadcast
Router(config-if)# ip rtp priority 16384 16383 25
Router(config-if)# service-policy output policy1
Router(config-if)# ppp multilink
Router(config-if)# ppp multilink fragment-delay 20
Router(config-if)# ppp multilink interleave
Router(config-if)# end
Router(config)# interface Serial0/1
Router(config-if)# bandwidth 64
Router(config-if)# ip address 1.1.1.2 255.255.255.0
Router(config-if)# no ip directed-broadcast
Router(config-if)# encapsulation ppp
Router(config-if)# ppp multilink
Router(config-if)# end

 
        
         
       
 
         
         
 
          
Note		 
          
 
           
 To make the virtual access interface function properly, the bandwidth policy-map class configuration command should not be configured on the virtual template. It needs to be configured on the actual interface, as shown in the example. 
           
 
         
 
         
       
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Multilink Bundle Configuration
 
     
 
      
 
        
         
       
 The following example configures a strict priority queue in a multilink bundle configuration with WFQ. The advantage to using multilink bundles is that you can specify different ip rtp priority parameters on different interfaces.
 
       
 The following commands create multilink bundle 1, which is configured for a maximum ip rtp priority bandwidth of 200 kbps.
 
       
Router(config)# interface multilink 1
Router(config-if)# ip address 172.17.254.161 255.255.255.248
Router(config-if)# no ip directed-broadcast
Router(config-if)# ip rtp priority 16384 16383 200
Router(config-if)# no ip mroute-cache
Router(config-if)# fair-queue 64 256 0
Router(config-if)# ppp multilink
Router(config-if)# ppp multilink fragment-delay 20
Router(config-if)# ppp multilink interleave

 
       
 The following commands create multilink bundle 2, which is configured for a maximum ip rtp priority bandwidth of 100 kbps:
 
       
Router(config)# interface multilink 2
Router(config-if)# ip address 172.17.254.162 255.255.255.248
Router(config-if)# no ip directed-broadcast
Router(config-if)# ip rtp priority 16384 16383 100
Router(config-if)# no ip mroute-cache
Router(config-if)# fair-queue 64 256 0
Router(config-if)# ppp multilink
Router(config-if)# ppp multilink fragment-delay 20
Router(config-if)# ppp multilink interleave

 
       
 In the next part of the example, the multilink-group command configures serial interface 2/0 to be part of multilink bundle 1:
 
       
Router(config)# interface serial 2/0
Router(config-if)# bandwidth 256
Router(config-if)# no ip address
Router(config-if)# no ip directed-broadcast
Router(config-if)# encapsulation ppp
Router(config-if)# no ip mroute-cache
Router(config-if)# no fair-queue
Router(config-if)# clockrate 256000
Router(config-if)# ppp multilink
Router(config-if)# multilink-group 1

 
       
 Next, serial interface 2/1 is configured to be part of multilink bundle 2.
 
       
Router(config)# interface serial 2/1
Router(config-if)# bandwidth 128
Router(config-if)# no ip address
Router(config-if)# no ip directed-broadcast
Router(config-if)# encapsulation ppp
Router(config-if)# no ip mroute-cache
Router(config-if)# no fair-queue
Router(config-if)# clockrate 128000
Router(config-if)# ppp multilink
Router(config-if)# multilink-group 2

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Debug
 
     
 
      
 
        
         
       
 The following example shows sample output from the debug priority command. In this example, 64 indicates the actual priority queue depth at the time the packet was dropped.
 
       
Router# debug priority
*Feb 28 16:46:05.659:WFQ:dropping a packet from the priority queue 64
*Feb 28 16:46:05.671:WFQ:dropping a packet from the priority queue 64
*Feb 28 16:46:05.679:WFQ:dropping a packet from the priority queue 64
*Feb 28 16:46:05.691:WFQ:dropping a packet from the priority queue 64
*Feb 28 16:46:05.699:WFQ:dropping a packet from the priority queue 64
*Feb 28 16:46:05.711:WFQ:dropping a packet from the priority queue 64
*Feb 28 16:46:05.719:WFQ:dropping a packet from the priority queue 64
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Examples Frame Relay IP RTP Priority Configuration
 
    
 
     
 
       
        
     
 
    
 
    
 
      
     
 
     
 
    
 
    
 
      
       
     
Example Strict Priority Service to Matching RTP Packets
 
     
 
      
 
        
         
       
 The following example first configures the Frame Relay map class called voip and then applies the map class to PVC 100 to provide strict priority service to matching RTP packets. In this example, RTP packets on PVC 100 with UDP ports in the range 16384 to 32764 will be matched and given strict priority service.
 
       
map-class frame-relay voip
 frame-relay cir 256000
 frame-relay bc 2560
 frame-relay be 600
 frame-relay mincir 256000
 no frame-relay adaptive-shaping
 frame-relay fair-queue
 frame-relay fragment 250
 frame-relay ip rtp priority 16384 16380 210
interface Serial5/0
 ip address 10.10.10.10 255.0.0.0
 no ip directed-broadcast
 encapsulation frame-relay
 no ip mroute-cache
 load-interval 30
 clockrate 1007616
 frame-relay traffic-shaping
 frame-relay interface-dlci 100
  class voip
 frame-relay ip rtp header-compression
 frame-relay intf-type dce
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Examples Frame Relay PVC Interface PQ Configuration
 
    
 
     
 
       
        
      
 This section provides configuration examples for Frame Relay PIPQ.
 
      
 This example shows the configuration of four PVCs on serial interface 0. DLCI 100 is assigned high priority, DLCI 200 is assigned medium priority, DLCI 300 is assigned normal priority, and DLCI 400 is assigned low priority.
 
      
 The following commands configure Frame Relay map classes with PVC priority levels:
 
      
Router(config)# map-class frame-relay HI
Router(config-map-class)# frame-relay interface-queue priority high
Router(config-map-class)# exit
Router(config)# map-class frame-relay MED
Router(config-map-class)# frame-relay interface-queue priority medium
Router(config-map-class)# exit
Router(config)# map-class frame-relay NORM
Router(config-map-class)# frame-relay interface-queue priority normal
Router(config-map-class)# exit
Router(config)# map-class frame-relay LOW
Router(config-map-class)# frame-relay interface-queue priority low
Router(config-map-class)# exit

 
      
 The following commands enable Frame Relay encapsulation and Frame Relay PIPQ on serial interface 0. The sizes of the priority queues are set at a maximum of 20 packets for the high priority queue, 40 for the medium priority queue, 60 for the normal priority queue, and 80 for the low priority queue.
 
      
Router(config)# interface Serial0
Router(config-if)# encapsulation frame-relay
Router(config-if)# frame-relay interface-queue priority 20 40 60 80

 
      
 The following commands assign priority to four PVCs by associating the DLCIs with the configured map classes:
 
      
Router(config-if)# frame-relay interface-dlci 100
Router(config-fr-dlci)# class HI
Router(config-fr-dlci)# exit
Router(config-if)# frame-relay interface-dlci 200
Router(config-fr-dlci)# class MED
Router(config-fr-dlci)# exit
Router(config-if)# frame-relay interface-dlci 300
Router(config-fr-dlci)# class NORM
Router(config-fr-dlci)# exit
Router(config-if)# frame-relay interface-dlci 400
Router(config-fr-dlci)# class LOW
Router(config-fr-dlci)# exit

 
     
 
    
 
    
 
     
 
     
 
    
 
   
 
   
 
     
      
    
Examples LLQ Configuration
 
    
 
     
 
       
        
     
 
    
 
    
 
      
     
 
     
 
    
 
    
 
      
       
     
Example ATM PVC Configuration
 
     
 
      
 
        
         
       
 In the following example, a strict priority queue with a guaranteed allowed bandwidth of 50 kbps is reserved for traffic that is sent from the source address 10.10.10.10 to the destination address 10.10.10.20, in the range of ports 16384 through 20000 and 53000 through 56000.
 
       
 First, the following commands configure access list 102 to match the desired voice traffic:
 
       
Router(config)# access-list 102 permit udp host 10.10.10.10 host 10.10.10.20 range 16384 20000
Router(config)# access-list 102 permit udp host 10.10.10.10 host 10.10.10.20 range 53000 56000

 
       
 Next, the class map voice is defined, and the policy map called policy1 is created; a strict priority queue for the class voice is reserved, a bandwidth of 20 kbps is configured for the class bar, and the default class is configured for WFQ. The service-policy command then attaches the policy map to the PVC interface 0/102 on the subinterface atm1/0.2.
 
       
Router(config)# class-map voice
Router(config-cmap)# match access-group 102
Router(config)# policy-map policy1
Router(config-pmap)# class voice
Router(config-pmap-c)# priority 50
Router(config-pmap)# class bar
Router(config-pmap-c)# bandwidth 20
Router(config-pmap)# class class-default
Router(config-pmap-c)# fair-queue
Router(config)# interface atm1/0.2
Router(config-subif)# pvc 0/102
Router(config-subif-vc)# service-policy output policy1

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Virtual Template Configuration
 
     
 
      
 
        
         
       
 The following example configures a strict priority queue in a virtual template configuration with CBWFQ. Traffic on virtual template 1 that is matched by access list 102 will be directed to the strict priority queue.
 
       
 First, the class map voice is defined, and the policy map called policy1 is created. A strict priority queue (with a guaranteed allowed bandwidth of 50 kbps) is reserved for the class called voice.
 
       
Router(config)# class-map voice
Router(config-cmap)# match access-group 102
Router(config)# policy-map policy1
Router(config-pmap)# class voice
Router(config-pmap-c)# priority 50

 
       
 Next, the service-policy command attaches the policy map called policy1 to virtual template 1.
 
       
Router(config)# multilink virtual-template 1
Router(config)# interface virtual-template 1
Router(config-if)# ip address 172.16.1.1 255.255.255.0
Router(config-if)# no ip directed-broadcast
Router(config-if)# service-policy output policy1
Router(config-if)# ppp multilink
Router(config-if)# ppp multilink fragment-delay 20
Router(config-if)# ppp multilink interleave
Router(config-if)# end
Router(config)# interface serial 2/0
Router(config-if)# bandwidth 256
Router(config-if)# no ip address
Router(config-if)# no ip directed-broadcast
Router(config-if)# encapsulation ppp
Router(config-if)# no fair-queue
Router(config-if)# clockrate 256000
Router(config-if)# ppp multilink

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Multilink Bundle Configuration
 
     
 
      
 
        
         
       
 The following example configures a strict priority queue in a multilink bundle configuration with CBWFQ. Traffic on serial interface 2/0 that is matched by access list 102 will be directed to the strict priority queue. The advantage to using multilink bundles is that you can specify different priority parameters on different interfaces. To specify different priority parameters, you would configure two multilink bundles with different parameters.
 
       
 First, the class map voice is defined, and the policy map called policy1 is created. A strict priority queue (with a guaranteed allowed bandwidth of 50 kbps) is reserved for the class called voice.
 
       
Router(config)# class-map voice
Router(config-cmap)# match access-group 102
Router(config)# policy-map policy1
Router(config-pmap)# class voice
Router(config-pmap-c)# priority 50

 
       
 The following commands create multilink bundle 1. The policy map called policy1 is attached to the bundle by the service-policy command.
 
       
Router(config)# interface multilink 1
Router(config-if)# ip address 172.17.254.161 255.255.255.248
Router(config-if)# no ip directed-broadcast
Router(config-if)# no ip mroute-cache
Router(config-if)# service-policy output policy1
Router(config-if)# ppp multilink
Router(config-if)# ppp multilink fragment-delay 20
Router(config-if)# ppp multilink interleave

 
       
 In the next part of the example, the multilink-group command configures serial interface 2/0 to be part of multilink bundle 1, which effectively directs traffic on serial interface 2/0 that is matched by access list 102 to the strict priority queue:
 
       
Router(config)# interface serial 2/0
Router(config-if)# bandwidth 256
Router(config-if)# no ip address
Router(config-if)# no ip directed-broadcast
Router(config-if)# encapsulation ppp
Router(config-if)# no fair-queue
Router(config-if)# clockrate 256000
Router(config-if)# ppp multilink
Router(config-if)# multilink-group 1

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Examples Distributed LLQ Configuration
 
    
 
     
 
       
        
     
 
    
 
    
 
      
     
 
     
 
    
 
    
 
      
       
     
Example Enabling PQ for an Amount of Available Bandwidth on an ATM Subinterface
 
     
 
      
 
        
         
       
 The priority command can be enabled on an ATM subinterface, and that subinterface must have only one enabled ATM PVC. This configuration provides a sufficient amount of ATM PVC support.
 
       
 In the following example, a priority queue with a guaranteed allowed bandwidth of 50 kbps is reserved for traffic that is sent from the source address 10.10.10.10 to the destination address 10.10.10.20, in the range of ports 16384 through 20000 and 53000 through 56000.
 
       
 First, the following commands configure access list 102 to match the desired voice traffic:
 
       
Router(config)# access-list 102 permit udp host 10.10.10.10 host 10.10.10.20 range 16384 20000
Router(config)# access-list 102 permit udp host 10.10.10.10 host 10.10.10.20 range 53000 56000

 
       
 Next, the traffic class called voice is defined, and the policy map called policy1 is created; a priority queue for the class voice is reserved with a guaranteed allowed bandwidth of 50 kpbs and an allowable burst size of 60 bytes, a bandwidth of 20 kbps is configured for the class called bar, and the default class is configured for flow-based fair queuing. The service-policy command then attaches the policy map to the PVC interface 0/102 on the subinterface atm1/0.
 
       
Router(config)# class-map voice
Router(config-cmap)# match access-group 102
Router(config)# policy-map policy1
Router(config-pmap)# class voice
Router(config-pmap-c)# priority 50 60
Router(config-pmap)# class bar
Router(config-pmap-c)# bandwidth 20
Router(config-pmap)# class class-default
Router(config-pmap-c)# fair-queue
Router(config)# interface atm1/0
Router(config-subif)# pvc 0/102
Router(config-subif)# service-policy output policy1

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Enabling PQ for a Percentage of Available Bandwidth on an ATM Subinterface
 
     
 
      
 
        
         
       
 The priority percentcommand can be enabled on an ATM subinterface, and that subinterface must have only one enabled ATM PVC. This configuration provides a sufficient amount of ATM PVC support.
 
       
 In the following example, a priority queue with a guaranteed allowed bandwidth percentage of 15 percent is reserved for traffic that is sent from the source address 10.10.10.10 to the destination address 10.10.10.20, in the range of ports 16384 through 20000 and 53000 through 56000.
 
       
 First, the following commands configure access list 102 to match the desired voice traffic:
 
       
Router(config)# access-list 102 permit udp host 10.10.10.10 host 10.10.10.20 range 16384 20000
Router(config)# access-list 102 permit udp host 10.10.10.10 host 10.10.10.20 range 53000 56000

 
       
 Next, the traffic class called voice is defined, and the policy map called policy1 is created; a priority queue for the class voice is reserved with a guaranteed allowed bandwidth percentage of 15 percent, a bandwidth percentage of 20 percent is configured for the class called bar, and the default class is configured for flow-based fair queueing. The service-policy command then attaches the policy map to the ATM subinterface 1/0.2.
 
       
Router(config)# class-map voice
Router(config-cmap)# match access-group 102
Router(config)# policy-map policy1
Router(config-pmap)# class voice
Router(config-pmap-c)# priority percent 15
Router(config-pmap)# class bar
Router(config-pmap-c)# bandwidth percent 20
Router(config-pmap)# class class-default
Router(config-pmap-c)# fair-queue
Router(config)# interface atm1/0.2
Router(config-subif)# service-policy output policy1

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Limiting the Transmission Ring Limit on an ATM Interface
 
     
 
      
 
        
         
       
 In the following example, the number of particles on the transmission ring of an ATM interface is limited to seven particles: 
 
       
Router(config)# interface atm 1/0/0
Router(config-if)# atm pvc 32 0 32 tx-ring-limit 7

 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
    
 
      
       
     
Example Limiting the Transmission Ring Limit on an ATM PVC Subinterface
 
     
 
      
 
        
         
       
 In the following example, the number of particles on the transmission ring of an ATM PVC subinterface is limited to ten particles: 
 
       
Router(config)# 
interface ATM1/0/0.1 point-to-point
Router(config-subif)# 
pvc 2/200
Router(config-if-atm-vc)# 
tx-ring-limit 10

 
       
 The tx-ring-limit command can be applied to several ATM PVC subinterfaces on a single interface. Every individual PVC can configure a transmission ring limit.
 
      
 
     
 
     
 
      
 
      
 
     
 
    
 
   
 
   
 
     
      
    
Examples LLQ for Frame Relay Configuration
 
    
 
     
 
       
        
      
 The following example shows how to configure a PVC shaped to a 64K CIR with fragmentation. The shaping queue is configured with a class for voice, two data classes for IP precedence traffic, and a default class for best-effort traffic. WRED is used as the drop policy on one of the data classes. 
 
      
 The following commands define class maps and the match criteria for the class maps: 
 
      
 !
 class-map voice
  match access-group 101
 !
 class-map immediate-data
  match access-group 102
 !
 class-map priority-data
  match access-group 103
 !
 access-list 101 permit udp any any range 16384 32767
 access-list 102 permit ip any any precedence immediate
 access-list 103 permit ip any any precedence priority

 
      
 The following commands create and define a policy map called mypolicy: 
 
      
 !
 policy-map mypolicy
  class voice
   priority 16
  class immediate-data
   bandwidth 32
   random-detect
  class priority-data
   bandwidth 16
  class class-default
   fair-queue 64
   queue-limit 20

 
      
 The following commands enable Frame Relay fragmentation and attach the policy map to DLCI 100: 
 
      
 !
 interface Serial1/0.1 point-to-point
  frame-relay interface-dlci 100
    class fragment
 !
 map-class frame-relay fragment
  frame-relay cir 64000
  frame-relay mincir 64000
  frame-relay bc 640
  frame-relay fragment 50
  service-policy output mypolicy

 
     
 
    
 
    
 
     
 
     
 
    
 
   
 
   
 
     
      
    
Examples Burst Size in LLQ Configuration
 
    
 
     
 
       
        
      
 The following example configures the burst parameter to 1250 bytes for the class called Voice, which has an assigned bandwidth of 1000 kbps:
 
      
policy policy1
  class Voice
   priority 1000 1250
 
     
 
    
 
    
 
     
 
     
 
    
 
   
 
   
 
     
      
    
Examples Per-VC Hold Queue Support for ATM Adapters
 
    
 
     
 
       
        
      
 The following example sets the per-VC hold queue to 55:
 
      
interface atm2/0.1
 pvc 1/101
  vc-hold-queue 55
 
     
 
    
 
    
 
     
 
     
 
    
 
   
 
   
 
     
      
    
 
 
    
 
     
 
       
        
      
Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks. Third party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1005R) 
 
      
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental. 
 
     
 
    
 
    
 
     
 
     
 
     
 
     
 
     
 
     
 
     
 
     
 
    
 
   
 
   
  
  
 


 
 
    

    

        

















    

        

    
    
    




















  
Was this Document Helpful?

  
    
    
  
  
      
      FeedbackFeedback
  






			
    

	

















  
    
  



    

			
    

	
















    
Contact Cisco