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Cisco IOS Quality of Service Solutions Command Reference, Release 12.3 T
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Introduction
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Quality of Service Commands: A through F
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Quality of Service Commands: I
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Quality of Sevice Commands: M
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Quality of Service Commands: O through P
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Quality of Service Commands: Q through R
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Quality of Service Commands: send qdm message through show ip nbar pdlm
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Quality of Service Commands: show ip nbar port-map through show qdm status
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Quality of Service Commands: show queue through vc-hold-queue
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Table Of Contents
clear ip rsvp signalling rate-limit
clear ip rsvp signalling refresh reduction
exponential-weighting-constant
frame-relay interface-queue priority
frame-relay ip rtp compression-connections
frame-relay ip tcp compression-connections
frame-relay ip tcp header-compression
frame-relay ip rtp header-compression
frame-relay map ip rtp header-compression
Quality of Service Commands
The following are quality of service (QoS) commands. The commands are arranged alphabetically.
access-list rate-limit
To configure an access list for use with committed access rate (CAR) policies, use the access-list rate-limit command in global configuration mode. To remove the access list from the configuration, use the no form of this command.
access-list rate-limit acl-index {precedence | mac-address | exp | mask mask}
no access-list rate-limit acl-index {precedence | mac-address | exp | mask mask}
Syntax Description
Defaults
No CAR access lists are configured.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to classify packets by the specified IP precedence, MAC address, or MPLS experimental field values for a particular CAR access list. You can then apply CAR policies, using the rate-limit command, to individual rate-limit access lists. When packets in an access list are classified in this manner, the packets with different IP precedences, MAC addresses, or MPLS experimental field values are treated differently by the CAR process.
You can specify only one command for each rate-limit access list. If you enter this command multiple times using the same access list number, the new command overwrites the previous command.
Use the mask keyword to assign multiple IP precedences or MPLS experimental field values to the same rate-limit list. To ascertain the mask value, perform the following steps:
Step 1
Decide which precedences you want to assign to this rate-limit access list.
Step 2
Step 3
Step 4
A mask of FF matches any precedence, and 00 does not match any precedence.
Examples
In the following example, MPLS experimental fields with the value of 7 are assigned to the rate-limit access list 200:
Router(config)# access-list rate-limit 200 7You can then use the rate-limit access list in a rate-limit command so that the rate limit is applied only to packets matching the rate-limit access list.
Router(config)# interface atm4/0.1 mplsRouter(config-if)# rate-limit input access-group rate-limit 200 8000 8000 8000 conform-action set-mpls-exp-transmit 4 exceed-action set-mpls-exp-transmit 0Related Commands
rate-limit
Configures CAR and DCAR policies.
show access-lists rate-limit
Displays information about rate-limit access lists.
auto discovery qos
To begin discovering and collecting data for configuring the AutoQoS for the Enterprise feature, use the auto discovery qos command in interface configuration mode. To stop discovering and collecting data, use the no form of this command.
auto discovery qos [trust]
no auto discovery qos
Syntax Description
Defaults
No data collection is performed.
Command Modes
Interface configuration
Command History
12.3(7)T
This command was introduced.
12.3(11)T
The trust mode was modified to classify packets by DSCP value rather than by protocol type.
Usage Guidelines
The auto discovery qos command initiates the Auto-Discovery (data collection) phase of the AutoQoS for the Enterprise feature. This command invokes NBAR protocol discovery to collect data and analyze the traffic at the egress direction of the interface.
The no auto discovery qos command terminates the Auto-Discovery phase and removes any data collection reports generated.
The trust keyword is used for the trusted model based on the specified DSCP marking. For more information, see the "Trusted Boundary" section of the AutoQoS for the Enterprise feature, Cisco IOS Release 12.3(7)T.
Examples
The following is a sample configuration showing the Auto-Discovery (data collection) phase of the AutoQoS for the Enterprise feature enabled on a serial2/1/1 subinterface.
Router> enableRouter# configure terminalRouter(config)# interface serial2/1.1Router(config-if)# frame-relay interface-dlci 58Router(config-if)# auto discovery qosRouter(config-if)# endRelated Commands
auto qos
To install the quality-of-service (QoS) class maps and policy maps created by the AutoQoS for the Enterprise feature, use the auto qos command in interface configuration mode. To remove the QoS policies, use the no form of this command.
auto qos
no auto qos
Syntax Description
This command has no arguments or keywords.
Defaults
No QoS policies are installed.
Command Modes
Interface configuration
Command History
Usage Guidelines
The class maps and policy maps are created from the templates that are automatically generated by the AutoQoS for the Enterprise feature. These templates (and the resulting class maps and policy maps) are generated on the basis of the data collected during the Auto-Discovery phase of the AutoQoS for the Enterprise feature. For more information about the Auto-Discovery phase, see the "Configuration Phases" section of the AutoQoS for the Enterprise feature, Cisco IOS Release 12.3(7)T.
The no auto qos command removes any AutoQoS-generated class maps and policy maps installed on the interface.
Examples
The following is a sample configuration showing the AutoQoS for the Enterprise feature enabled on a serial2/1/1 subinterface. In this configuration, the AutoQoS class maps and policy maps will be installed on the serial2/1 interface.
Router> enableRouter# configure terminalRouter(config)# interface serial2/1Router(config-if)# frame-relay interface-dlci 58Router(config-if)# auto qosRouter(config-if)# endRelated Commands
auto qos voip
To configure the AutoQoS — VoIP feature on an interface, use the auto qos voip command in interface configuration mode or Frame Relay DLCI configuration mode. To remove the AutoQoS — VoIP feature from an interface, use the no form of this command.
auto qos voip [trust] [fr-atm]
no auto qos voip [trust] [fr-atm]
Syntax Description
Defaults
Disabled
Command Modes
Interface configuration
Frame Relay DLCI configuration (for use with Frame Relay DLCIs)
Command History
Usage Guidelines
To enable the AutoQoS — VoIP feature for Frame Relay-to-ATM interworking, the fr-atm keyword must be configured explicitly. However, the fr-atm keyword affects low-speed DLCIs only. It does not affect high-speed DLCIs.
Note
Depending on whether the trust keyword has been configured for this command, the AutoQoS — VoIP feature automatically creates one of the two following policy maps:
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Both of these policy maps, designed to handle the Voice over IP (VoIP) traffic on an interface or a permanent virtual circuit (PVC), can be modified to suit the quality of service (QoS) requirements of the network. To modify these policy maps, use the appropriate Cisco IOS command.
These policy maps should not be attached to an interface or PVC by using the service-policy command. If the policy maps are attached in this manner, the AutoQoS — VoIP feature (that is, the policy maps, class maps, and access control lists (ACLs)) will not be removed properly when the no auto qos voip command is configured.
For low-speed Frame Relay DLCIs interconnected with ATM PVCs in the same network, the fr-atm keyword must be explicitly configured in the auto qos voip command to configure the AutoQoS — VoIP feature properly. That is, the command must be configured as auto qos voip fr-atm.
For low-speed Frame Relay DLCIs configured with Frame Relay-to-ATM, Multilink PPP (MLP) over Frame Relay (MLPoFR) is configured automatically. The subinterface must have an IP address. When MLPoFR is configured, this IP address is removed and put on the MLP bundle. The AutoQoS — VoIP feature must also be configured on the ATM side by using the auto qos voip command.
The auto qos voip command is not supported on subinterfaces.
The auto qos voip command is available for Frame Relay DLCIs.
Disabling AutoQoS — VoIP
The no auto qos voip command disables the AutoQoS — VoIP feature and removes the configurations associated with the feature.
When the no auto qos voip command is used, the no forms of the individual commands originally generated by the AutoQoS — VoIP feature are configured. With the use of individual no forms of the commands, the system defaults are reinstated. The no forms of the commands will be applied just as if the user had entered the commands individually. As the configuration reinstating the default setting is applied, any messages resulting from the processing of the commands are displayed.
Note
Examples
The following example shows the AutoQoS — VoIP feature configured on a serial point-to-point subinterface 4/1.2. In this example, both the trust and fr-atm keywords are configured.
Router> enableRouter# configure terminalRouter(config)# interface serial4/1.2 point-to-point
Router(config-if)# bandwidth 100
Router(config-if)# ip address 192.168.0.0 255.255.255.0
Router(config-if)# frame-relay interface-dlci 102
Router(config-fr-dlci)# auto qos voip trust fr-atm
Router(config-if# exit
Related Commands
bandwidth (policy-map class)
To specify or modify the bandwidth allocated for a class belonging to a policy map, use the bandwidth command in policy-map class configuration mode. To remove the bandwidth specified for a class, use the no form of this command.
bandwidth {bandwidth-kbps | remaining percent percentage | percent percentage}
no bandwidth {bandwidth-kbps | remaining percent percentage | percent percentage}
Syntax Description
Defaults
No bandwidth is specified
Command Modes
Policy-map class configuration
Command History
Usage Guidelines
You should use the bandwidth command when you configure a policy map for a class defined by the class-map command. The bandwidth command specifies the bandwidth for traffic in that class. Class-based weighted fair queueing (CBWFQ) derives the weight for packets belonging to the class from the bandwidth allocated to the class. CBWFQ then uses the weight to ensure that the queue for the class is serviced fairly.
Specifying Bandwidth as a Percentage
Besides specifying the amount of bandwidth in kbps, you can specify bandwidth as a percentage of either the available bandwidth or the total bandwidth. During periods of congestion, the classes are serviced in proportion to their configured bandwidth percentages. Available bandwidth is equal to the interface bandwidth minus the sum of all bandwidths reserved by the Resource Reservation Protocol (RSVP) feature, the IP RTP Priority feature, and the Low Latency Queueing (LLQ) feature.
Note
Bandwidth Command Restrictions
The following restrictions apply to the bandwidth command:
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For more information on bandwidth allocation, refer to the chapter "Congestion Management Overview" in the Cisco IOS Quality of Service Solutions Configuration Guide.
Note that when the policy map containing class policy configurations is attached to the interface to stipulate the service policy for that interface, available bandwidth is assessed. If a policy map cannot be attached to a particular interface because of insufficient interface bandwidth, then the policy is removed from all interfaces to which it was successfully attached.
Queue Limits
The bandwidth command can be used with the Modular Command-Line Interface (MQC) to specify the bandwidth for a particular class. When used with the MQC, the bandwidth command uses a default queue limit for the class. This queue limit can be modified using the queue-limit command, thereby overriding the default set by the bandwidth command.
Note
Examples
CBWFQ Bandwidth Guarantee Example
The following example shows how bandwidth is guaranteed when only CBWFQ is configured:
! The following commands create a policy map with two classes:policy-map policy1class class1bandwidth percent 50exitclass class2bandwidth percent 25exitend!The following commands attach the policy to interface serial3/2:interface serial3/2service output policy1endThe following output from the show policy-map command shows the configuration for the policy map called policy1:
Router# show policy-map policy1Policy Map policy1Class class1Weighted Fair QueueingBandwidth 50 (%) Max Threshold 64 (packets)Class class2Weighted Fair QueueingBandwidth 25 (%) Max Threshold 64 (packets)The output from the show policy-map interface command shows that 50 percent of the interface bandwidth is guaranteed for the class called class1, and 25 percent is guaranteed for the class called class2. The output displays the amount of bandwidth as both a percentage and a number of kbps.
Router# show policy-map interface serial3/2Serial3/2Service-policy output:policy1Class-map:class1 (match-all)0 packets, 0 bytes5 minute offered rate 0 bps, drop rate 0 bpsMatch:noneWeighted Fair QueueingOutput Queue:Conversation 265Bandwidth 50 (%)Bandwidth 772 (kbps) Max Threshold 64 (packets)(pkts matched/bytes matched) 0/0(depth/total drops/no-buffer drops) 0/0/0Class-map:class2 (match-all)0 packets, 0 bytes5 minute offered rate 0 bps, drop rate 0 bpsMatch:noneWeighted Fair QueueingOutput Queue:Conversation 266Bandwidth 25 (%)Bandwidth 386 (kbps) Max Threshold 64 (packets)(pkts matched/bytes matched) 0/0(depth/total drops/no-buffer drops) 0/0/0Class-map:class-default (match-any)0 packets, 0 bytes5 minute offered rate 0 bps, drop rate 0 bpsMatch:anyIn this example, interface serial3/2 has a total bandwidth of 1544 kbps. During periods of congestion, 50 percent (or 772 kbps) of the bandwidth is guaranteed to the class called class1, and 25 percent (or 386 kbps) of the link bandwidth is guaranteed to the class called class2.
CBWFQ and LLQ Bandwidth Allocation Example
The following output from the show policy-map command shows the configuration for a policy map called p1:
Router# show policy-map p1Policy Map p1Class voiceWeighted Fair QueueingStrict PriorityBandwidth 500 (kbps) Burst 12500 (Bytes)Class class1Weighted Fair QueueingBandwidth remaining 50 (%) Max Threshold 64 (packets)Class class2Weighted Fair QueueingBandwidth remaining 25 (%) Max Threshold 64 (packets)The following output from the show policy-map interface command on serial interface 3/2 shows that 500 kbps of bandwidth is guaranteed for the class called voice1. The classes called class1 and class2 receive 50 percent and 25 percent of the remaining bandwidth, respectively. Any unallocated bandwidth is divided proportionally among class1, class2, and any best-effort traffic classes.
Note
Router# show policy-map interface serial3/2Serial3/2Service-policy output:p1Class-map:voice (match-all)0 packets, 0 bytes5 minute offered rate 0 bps, drop rate 0 bpsMatch:ip precedence 5Weighted Fair QueueingStrict PriorityOutput Queue:Conversation 264Bandwidth 500 (kbps) Burst 12500 (Bytes)(pkts matched/bytes matched) 0/0(total drops/bytes drops) 0/0Class-map:class1 (match-all)0 packets, 0 bytes5 minute offered rate 0 bps, drop rate 0 bpsMatch:noneWeighted Fair QueueingOutput Queue:Conversation 265Bandwidth remaining 50 (%) Max Threshold 64 (packets)(pkts matched/bytes matched) 0/0(depth/total drops/no-buffer drops) 0/0/0Class-map:class2 (match-all)0 packets, 0 bytes5 minute offered rate 0 bps, drop rate 0 bpsMatch:noneWeighted Fair QueueingOutput Queue:Conversation 266Bandwidth remaining 25 (%) Max Threshold 64 (packets)(pkts matched/bytes matched) 0/0(depth/total drops/no-buffer drops) 0/0/0Class-map:class-default (match-any)0 packets, 0 bytes5 minute offered rate 0 bps, drop rate 0 bpsMatch:anyRelated Commands
bump
To configure the bumping rules for a virtual circuit (VC) class that can be assigned to a VC bundle, use the bump command in VC-class configuration mode. To remove the explicit bumping rules for the VCs assigned to this class and return to the default condition of implicit bumping, use the no bump explicit command or the bump implicit command. To specify that the VC bundle members do not accept any bumped traffic, use the no form of this command.
To configure the bumping rules for a specific VC or permanent virtual circuit (PVC) member of a bundle, use the bump command in bundle-vc or SVC (switched virtual circuit)-bundle-member configuration mode. To remove the explicit bumping rules for the VC or PVC bundle member and return to the default condition of implicit bumping, use the bump implicit command. To specify that the VC or PVC bundle member does not accept any bumped traffic, use the no bump traffic command.
bump {explicit precedence-level | implicit | traffic}
no bump {explicit precedence-level | implicit | traffic}
Syntax Description
Defaults
Implicit bumping
Permit bumping (VCs accept bumped traffic)
Command Modes
VC-class configuration (for a VC class)
Bundle-vc configuration (for an ATM VC bundle member)
SVC-bundle-member configuration (for an SVC bundle member)
Command History
Usage Guidelines
Use the bump command in bundle-vc configuration mode (for an ATM VC bundle member), SVC-bundle-member configuration mode (for an SVC bundle member) to configure bumping rules for a discrete VC or PVC bundle member. Use the bump command in vc-class configuration mode to configure a VC class that can be assigned to a bundle member.
The effects of different bumping configuration approaches are as follows:
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Note
To use this command in VC-class configuration mode, you must enter the vc-class atm global configuration command before you enter this command.
To use this command to configure an individual bundle member in bundle-VC configuration mode, first issue the bundle command to enter bundle configuration mode for the bundle to which you want to add or modify the VC member to be configured. Then use the pvc-bundle command to specify the VC to be created or modified and enter bundle-vc configuration mode.
This command has no effect if the VC class that contains the command is attached to a standalone VC; that is, if the VC is not a bundle member. In this case, the attributes are ignored by the VC.
VCs in a VC bundle are subject to the following configuration inheritance guidelines (listed in order of next-highest precedence):
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Examples
The following example configures the class called "five" to define parameters applicable to a VC in a bundle. If the VC goes down, traffic will be directed (bumped explicitly) to a VC mapped with precedence level 7.
vc-class atm fiveubr 5000precedence 5bump explicit 7The following example configures the class called "premium-class" to define parameters applicable to a VC in a bundle. Unless overridden with a bundle-vc bump configuration, the VC that uses this class will not allow other traffic to be bumped onto it.
vc-class atm premium-classno bump trafficbump explicit 7Related Commands
bundle
To create a bundle or modify an existing bundle to enter bundle configuration mode, use the bundle command in subinterface configuration mode. To remove the specified bundle, use the no form of this command.
bundle bundle-name
no bundle bundle-name
Syntax Description
Defaults
No bundle is specified.
Command Modes
Subinterface configuration
Command History
Usage Guidelines
From within bundle configuration mode you can configure the characteristics and attributes of the bundle and its members, such as the encapsulation type for all virtual circuits (VCs) in the bundle, the bundle management parameters, the service type, and so on. Attributes and parameters you configure in bundle configuration mode are applied to all virtual circuit (VC) members of the bundle.
VCs in a VC bundle are subject to the following configuration inheritance guidelines (listed in order of next highest precedence):
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To display status on bundles, use the show atm bundle and show atm bundle statistics commands.
Examples
The following example configures a bundle called new-york. The example specifies the IP address of the subinterface and the router protocol—the router uses Intermediate System-to-Intermediate System (IS-IS) as an IP routing protocol—then configures the bundle.
interface a1/0.1 multipoint ip address 10.0.0.1 255.255.255.0 ip router isis bundle new-yorkRelated Commands
bundle svc
To create or modify a switched virtual circuit (SVC) bundle, use the bundle svc command in interface configuration mode. To remove the specified bundle, use the no form of this command.
bundle svc bundle-name nsap nsap-address
no bundle svc bundle-name nsap nsap-address
Syntax Description
Defaults
No SVC bundle is created or modified.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command causes the system to enter SVC-bundle configuration mode. The bundle name must be the same on both sides of the VC.
From SVC-bundle configuration mode, you can configure the characteristics and attributes of the bundle and its members, such as the encapsulation type for all virtual circuits (VCs) in the bundle, the bundle management parameters, the service type, and so on. Attributes and parameters you configure in SVC-bundle configuration mode are applied to all VC members of the bundle.
VCs in a VC bundle are subject to the following configuration inheritance guidelines (listed in order of next-highest precedence):
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To display the status of bundles, use the show atm bundle svc and show atm bundle svc statistics commands.
Examples
The following example configures an SVC bundle called "sanfrancisco":
interface ATM1/0.1 multipointip address 170.100.9.2 255.255.255.0atm esi-address 111111111111.11bundle svc sanfrancisco nsap 47.0091810000000003E3924F01.999999999999.99protocol ip 170.100.9.1broadcastoam retry 4 3 10encapsulation aal5snapoam-bundle managesvc-bundle sevenclass-vc sevensvc-bundle sixclass-vc sixsvc-bundle fiveclass-vc fivesvc-bundle fourclass-vc foursvc-bundle threeclass-vc threesvc-bundle twoclass-vc twosvc-bundle oneclass-vc onesvc-bundle zeroclass-vc zeroRelated Commands
class (EtherSwitch)
To define a traffic classification for a policy to act on using the class-map name or access group, use the class command in policy-map configuration mode. To delete an existing class map, use the no form of this command.
class class-map-name [access-group acl-index-or-name]
no class class-map-name
Syntax Description
Defaults
No policy-map class maps are defined.
Command Modes
Policy-map configuration
Command History
Usage Guidelines
Before you use the class (EtherSwitch) command, use the policy-map global configuration command to identify the policy map and to enter policy-map configuration mode. After you specify a policy map, you can configure a policy for new classes or modify a policy for any existing classes in that policy map. You attach the policy map to an interface by using the service-policy interface configuration command; however, you cannot attach one that uses an ACL classification to the egress direction.
The class name that you specify in the policy map ties the characteristics for that class to the class map and its match criteria as configured by using the class-map global configuration command.
The class (EtherSwitch) command performs the same function as the class-map global configuration command. Use the class (EtherSwitch) command when a new classification, which is not shared with any other ports, is needed. Use the class-map command when the map is shared among many ports.
Note
After entering the class (EtherSwitch) command, you enter policy-map class configuration mode. When you are in this mode, these configuration commands are available:
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To return to policy-map configuration mode, use the exit command. To return to privileged EXEC mode, use the end command.
Note
Examples
The following example shows how to create a policy map named "policy1." When attached to the ingress port, it matches all the incoming traffic defined in class1 and polices the traffic at an average rate of 1 Mbps and bursts at 131072 bytes. Traffic exceeding the profile is dropped.
Router(config)# policy-map policy1Router(config-pmap)# class class1Router(config-pmap-c)# police 1000000 131072 exceed-action dropRouter(config-pmap-c)# exitRouter(config-pmap)#You can verify your settings by entering the show policy-map privileged EXEC command.
Related Commands
class (policy-map)
To specify the name of the class whose policy you want to create or change or to specify the default class (commonly known as the class-default class) before you configure its policy, use the class command in QoS policy-map configuration mode. To remove a class from the policy map, use the no form of this command.
class {class-name | class-default}
no class {class-name | class-default}
Syntax Description
class-name
The name of the class for which you want to configure or modify policy.
class-default
Specifies the default class so that you can configure or modify its policy.
Defaults
No class is specified.
Command Modes
QoS policy-map configuration
Command History
Usage Guidelines
Policy Map Configuration Mode
Within a policy map, the class (policy-map) command can be used to specify the name of the class whose policy you want to create or change. First, the policy map must be identified.
To identify the policy map (and enter the required QoS policy-map configuration mode), use the policy-map command before you use the class (policy-map) command. After you specify a policy map, you can configure policy for new classes or modify the policy for any existing classes in that policy map.
Class Characteristics
The class name that you specify in the policy map ties the characteristics for that class—that is, its policy—to the class map and its match criteria, as configured using the class-map command.
When you configure policy for a class and specify its bandwidth and attach the policy map to an interface, class-based weighted fair queueing (CBWFQ) determines if the bandwidth requirement of the class can be satisfied. If so, CBWFQ allocates a queue for the bandwidth requirement.
When a class is removed, available bandwidth for the interface is incremented by the amount previously allocated to the class.
The maximum number of classes you can configure for a router—and, therefore, within a policy map—is 64.
Predefined Default Class
The predefined default class called class-default is available for you to use. The class class-default is the class to which traffic is directed if that traffic does not match any of the match criteria in the configured class maps.
Tail Drop or WRED
You can define a class policy to use either tail drop by using the queue-limit command or Weighted Random Early Detection (WRED) by using the random-detect command. When using either tail drop or WRED, note the following points:
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Examples
The following example configures three class policies included in the policy map called policy1. Class1 specifies policy for traffic that matches access control list 136. Class2 specifies policy for traffic on interface ethernet101. The third class is the default class to which packets that do not satisfy configured match criteria are directed.
! The following commands create class-maps class1 and class2! and define their match criteria:class-map class1match access-group 136class-map class2
