Table Of Contents

ATM Multilink PPP Support on Multiple VCs

Finding Feature Information

Contents

Restrictions for ATM Multilink PPP Support on Multiple VCs

Information About ATM Multilink PPP Support on Multiple VCs

Benefits of ATM Multilink PPP Support on Multiple VCs

How to Configure ATM Multilink PPP Support on Multiple VCs

Defining the Service Policy Using the MQC

Defining a Multilink MLP Bundle Interface

Defining the Virtual Templates for Member Links

Defining the PVCs and Making Them Bundle Member Links

Verifying ATM Multilink PPP Support on Multiple VCs

Monitoring ATM Multilink PPP Support on Multiple VCs

Configuration Examples for ATM Multilink PPP Support on Multiple VCs

Defining the Service Policy Using the MQC Configuration: Example

Defining a Multilink MLP Bundle Interface Configuration: Example

Defining Virtual Templates for Member Links Configuration: Example

Defining PVCs and Making Them Bundle Member Links Configuration: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Feature Information for ATM Multilink PPP Support on Multiple VCs

Glossary

ATM Multilink PPP Support on Multiple VCs

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First Published: November 25, 2002

Last Updated: November 20, 2009

The ATM Multilink PPP Support on Multiple VCs feature facilitates traffic load balancing on high-speed virtual circuits (VCs) using multilink PPP (MLP) over Frame Relay and ATM. It also facilitates traffic load balancing by using MLP to combine packet datagrams on high-speed VCs as a means of transporting both the voice and data traffic more efficiently.

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 for ATM Multilink PPP Support on Multiple VCs" section.

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

Contents

•Restrictions for ATM Multilink PPP Support on Multiple VCs

•Information About ATM Multilink PPP Support on Multiple VCs

•How to Configure ATM Multilink PPP Support on Multiple VCs

•Configuration Examples for ATM Multilink PPP Support on Multiple VCs

•Additional References

•Feature Information for ATM Multilink PPP Support on Multiple VCs

•Glossary

Restrictions for ATM Multilink PPP Support on Multiple VCs

The ATM Multilink PPP Support on Multiple VCs feature does not support the following commands and functionality. The configuration accepts these commands, but the commands have no effect:

•ppp interleave

•ppp multilink fragment-delay

The ATM Multilink PPP Support on Multiple VCs feature does not support the link fragmentation and interleaving (LFI) functionality.

Information About ATM Multilink PPP Support on Multiple VCs

Load balancing operates at Layer 2 or Layer 3 (the network layer) of the Open System Interconnection (OSI) reference model. Layer 3 load balancing is independent of any link-layer technologies. The ATM Multilink Point-to-Point Protocol (PPP) Support on Multiple VCs feature implements load balancing at Layer 2 and depends on having MLP enabled at the link layer.

The ATM MLP functionality keeps track of packet sequencing, and this functionality buffers any packets that arrive early. With this ability, ATM MLP preserves packet order across the entire bundle.

In addition to MLP, low latency queueing (LLQ) and class-based weighted fair queueing (CBWFQ) are used to prioritize and differentiate the voice and data packets. LLQ and CBWFQ help to ensure that the voice and data traffic receive the proper quality of service (QoS) treatment (such as the correct priority queue assignment) when the voice and data traffic are transmitted.

For more information about LLQ and CBWFQ, see the Cisco IOS Quality of Service Solutions Configuration Guide.

Benefits of ATM Multilink PPP Support on Multiple VCs

Facilitates More Efficient Traffic Load Balancing

The ATM Multilink PPP Support on Multiple VCs feature supports the transport of real-time (voice) and other (data) traffic on Frame Relay and ATM VCs.

How to Configure ATM Multilink PPP Support on Multiple VCs

This section contains the following tasks:

•Defining the Service Policy Using the MQC (required)

•Defining a Multilink MLP Bundle Interface (required)

•Defining the Virtual Templates for Member Links (required)

•Defining the PVCs and Making Them Bundle Member Links (required)

•Verifying ATM Multilink PPP Support on Multiple VCs (required)

•Monitoring ATM Multilink PPP Support on Multiple VCs (optional)

Defining the Service Policy Using the MQC

Perform this task to define the service policy using the MQC. The MQC allows you to create class maps and define service policies. Service policies are used to create classes and set match criteria for classifying traffic.

SUMMARY STEPS

1. enable

2. configure terminal

3. class-map class-map-name [match-all | match-any]

4. match ip precedence ip-precedence-value [ip-precedence-value ip-precedence-value ip-precedence-value]

5. exit

6. policy-map policy-name

7. class-map class-map-name [match-all | match-any]

8. bandwidth {bandwidth-kbps | percent percent}

9. end

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	class-map class-map-name [match-all | match-any] Example: Router(config)# class-map class1	Specifies the name of the class map to be created and enters class-map configuration mode. If match-all or match-any value is not specified, traffic must match all the match criteria to be classified as part of the class map.
Step 4	match ip precedence ip-precedence-value [ip-precedence-value ip-precedence-value ip-precedence-value] Example: Router(config-cmap)# match ip precedence 3 2 4	Identifies IP precedence values as match criteria.
Step 5	exit Example: Router(config-cmap)# exit	Exits class-map configuration mode.
Step 6	policy-map policy-name Example: Router(config)# policy-map policy1	Specifies the name of the policy map to be created and enters policy-map configuration mode.
Step 7	class-map class-map-name [match-all | match-any] Example: Router(config-pmp)# class class2	Classifies traffic based on the class map specified and enters policy-map class configuration mode.
Step 8	bandwidth {bandwidth-kbps | percent percent} Example: Router (config-pmap-c)# bandwidth 45	Specifies a minimum bandwidth guarantee to a traffic class in periods of congestion. •A minimum bandwidth guarantee can be specified in kbps or by a percentage of the overall available bandwidth.
Step 9	end Example: Router(config-pmp)# end	Exits class-map configuration mode.

Defining a Multilink MLP Bundle Interface

Perform this task to define a multilink MLP bundle interface. The purpose of a multilink bundle interface is to combine more than one permanent virtual circuit (PVC). All configurations for PPP over ATM links are placed into virtual templates, and the bundle parameters are placed into the multilink bundle.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ip address ip-address mask [secondary]

5. load-interval seconds

6. no cdp enable

7. service-policy output policy-name

8. ppp multilink

9. ppp multilink fragment disable

10. ppp multilink group group-number

11. end

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	interface type number Example: Router(config)# interface multilink 34	Configures an interface type and enters interface configuration mode.
Step 4	ip address ip-address mask [secondary] Example: Router(config-if)# ip address 209.165.201.1 255.255.255.0	Sets a primary or secondary IP address for an interface.
Step 5	load-interval seconds Example: Router(config-if)# load-interval 60	Changes the length of time for which data is used to compute load statistics.
Step 6	no cdp enable Example: Router(config-if)# no cdp enable	Disables Cisco Discovery Protocol (CDP) on an interface.
Step 7	service-policy output policy-name Example: Router(config-if)# service-policy output policy1	Attaches the specified policy map to the output interface.
Step 8	ppp multilink Example: Router(config-if)# ppp multilink	Enables MLP on an interface.
Step 9	ppp multilink fragment disable Example: Router(config-if)# ppp multilink fragment disable	Disables packet fragmentation.
Step 10	ppp multilink group group-number Example: Router(config-if)# ppp multilink group 54	Restricts a physical link to joining only a designated multilink-group interface.
Step 11	end Example: Router(config-if)# end	Exits interface configuration mode.

Defining the Virtual Templates for Member Links

Perform this task to define the virtual templates for member links.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. no ip address

5. load-interval seconds

6. ppp multilink

7. ppp multilink group group-number

8. end

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	interface type number Example: Router(config)# interface multilink 34	Configures an interface type and enters interface configuration mode.
Step 4	no ip address Example: Router(config-if)# no ip address	Removes existing IP addresses or disables IP processing.
Step 5	load-interval seconds Example: Router(config-if)# load-interval 30	Changes the length of time for which data is used to compute load statistics.
Step 6	ppp multilink Example: Router(config-if)# ppp multilink	Enables MLP on the interface.
Step 7	ppp multilink group group-number Example: Router(config-if)# ppp multilink-group 44	Restricts a physical link to joining only a designated multilink-group interface.
Step 8	end Example: Router(config-if)# end	Exits interface configuration mode.

Defining the PVCs and Making Them Bundle Member Links

Perform this task to define the PVCs and make them bundle member links.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface atm slot/0

       or

       interface atm slot/port

4. no ip address

5. load interval seconds

6. atm ilmi-keepalive [seconds [retry [seconds]]]

7. pvc [name] vpi/vci

8. vbr-nrt output-pcr output-scr [output-mbs]

9. tx-ring-limit ring-limit

10. protocol ppp virtual-template number

11. end

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	interface atm slot/0 or interface atm slot/port Example: Router(config)# interface atm 2/0 or Router(config)# interface atm 2/1	Specifies the ATM interface type and enters interface configuration mode.
Step 4	no ip address Example: Router(config-if)# no ip address	Removes an IP address or disables IP processing.
Step 5	load interval seconds Example: Router(config-if)# load interval 30	Changes the length of time for which data is used to compute load statistics.
Step 6	atm ilmi-keepalive [seconds [retry [seconds]]] Example: Router(config-if)# atm ilmi-keepalive	Enables Interim Local Management Interface (ILMI) keepalives.
Step 7	pvc [name] vpi/vci Example: Router(config-if)# pvc pvc1 0/56	Creates an ATM PVC. Enters interface-ATM-VC configuration mode.
Step 8	vbr-nrt output-pcr output-scr [output-mbs] Example: Router(config-if-atm-vc)# vbr-nrt 45 4 45	Configures the variable bit rate (VBR)-non real time (NRT) QoS and specifies output peak cell rate, output sustainable cell rate, and output maximum burst cell size.
Step 9	tx-ring-limit ring-limit Example: Router(config-if-atm-vc)# tx-ring-limit 3	Limits the number of particles or packets that can be used on a transmission ring on an interface. •Use this command to tune the transmission ring to assign most of the packets to the Layer 3 queues.
Step 10	protocol ppp virtual-template number Example: Router(config-if-atm-vc)# protocol ppp virtual-template 34	Specifies that PPP is established over the ATM PVC using the configuration from the specified virtual template and enters interface configuration mode.
Step 11	end Example: Router(config-if)# end	Exits interface configuration mode.

Verifying ATM Multilink PPP Support on Multiple VCs

Perform this task to display information about ATM Multilink PPP Support on Multiple VCs:

SUMMARY STEPS

1. enable

2. show frame-relay pvc [[interface interface] [dlci] [64-bit] | summary [all]]

3. show interfaces

4. show policy-map

5. show ppp multilink

6. show queueing

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	show atm pvc Example: Router# show atm pvc	Displays all ATM PVCs and traffic information.
Step 3	show frame-relay pvc [[interface interface] [dlci] [64-bit] | summary [all]] Example: Router# show frame-relay pvc 16	Displays statistics about PVCs for Frame Relay interfaces.
Step 4	show interfaces Example: Router# show interfaces	Displays interleaving statistics. •Interleaving data is displayed only if interleaving occurs.
Step 5	show policy-map Example: Router# show policy-map	Displays the configuration of all classes for a specified service policy map or all classes for all existing policy maps.
Step 6	show ppp multilink Example: Router# show ppp multilink	Displays bundle information for the MLP bundles and their PPP links in the router.
Step 7	show queueing Example: Router# show queueing	Lists all or selected configured queueing strategies.

Monitoring ATM Multilink PPP Support on Multiple VCs

Perform this task to monitor ATM Multilink PPP Support on Multiple VCs.

SUMMARY STEPS

1. enable

2. debug atm errors

3. debug atm events

4. debug ppp error

5. debug ppp multilink events

6. debug voice RTP

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	debug atm errors Example: Router# debug atm errors	Displays ATM errors.
Step 3	debug atm events Example: Router# debug atm events	Displays ATM events.
Step 4	debug ppp error Example: Router# debug ppp error	Displays information on traffic and exchanges in an internetwork implementing the PPP.
Step 5	debug ppp multilink events Example: Router# debug ppp multilink events	Displays information about events affecting multilink groups.
Step 6	debug voice RTP Example: Router# debug voice RTP	Displays information about the interleaving of voice and data packets. •The debug voice RTP command has memory overhead and should not be used when memory is scarce or when traffic is very high.

Configuration Examples for ATM Multilink PPP Support on Multiple VCs

This section provides the following configuration examples:

•Defining the Service Policy Using the MQC Configuration: Example

•Defining a Multilink MLP Bundle Interface Configuration: Example

•Defining Virtual Templates for Member Links Configuration: Example

•Defining PVCs and Making Them Bundle Member Links Configuration: Example

Defining the Service Policy Using the MQC Configuration: Example

The following example shows how to configure a service policy using the MQC:

Router> enable

Router# configure terminal

Router(config)# class-map match-all DATA

Router(config-cmap)# match ip precedence 0

Router(config-cmap)# class-map match-all VOICE

Router(config-cmap)# match access-group 100

Router(config-cmap)# policy-map CISCO

Router(config-pmap)# class VOICE

Router(config-pmap-c)# priority percent 70

Router(config-pmap-c)# class DATA

Router(config-pmap-c)# bandwidth percent 5

Router(config-pmap-c)# access-list 100 permit udp any any precedence critical

Defining a Multilink MLP Bundle Interface Configuration: Example

The following example shows how to define a multilink bundle for the mulitilink interface:

Router> enable

Router# configure terminal

Router(config)# interface Multilink1

Router(config-if)# ip address 10.2.1.1 255.0.0.0

Router(config-if)# load-interval 30

Router(config-if)# no cdp enable

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

Router(config-if)# ppp multilink fragment disable

Router(config-if)# ppp multilink group 1

Defining Virtual Templates for Member Links Configuration: Example

The following example shows how to define virtual templates for member links:

Router> enable

Router# configure terminal

Router(config)# interface Virtual-Template1

Router(config-if)# no ip address

Router(config-if)# load-interval 30

Router(config-if)# ppp multilink

Router(config-if)# ppp multilink group 1

Router(config-if)# interface Virtual-Template2

Router(config-if)# no ip address

Router(config-if)# load-interval 30

Router(config-if)# ppp multilink

Router(config-if)# ppp multilink group 1

Defining PVCs and Making Them Bundle Member Links Configuration: Example

The following example shows how to define and configure PVCs as bundle members:

Router> enable

Router# configure terminal

Router(config)# interface atm 6/0

Router(config-if)# no ip address

Router(config-if)# load-interval 30

Router(config-if)# atm ilmi-keepalive

Router(config-if)# pvc 0/34 

Router(config-if-atm-vc)# vbr-nrt 1536 1536

Router(config-if-atm-vc)# tx-ring-limit 5

Router(config-if-atm-vc)# protocol ppp Virtual-Template1

Router(config-if-atm-vc)# pvc 0/35 

Router(config-if-atm-vc)# vbr-nrt 800 800

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

Router(config-if-atm-vc)# protocol ppp Virtual-Template2

Router(config-if-atm-vc)# pvc 0/36 

Router(config-if-atm-vc)# vbr-nrt 800 400 94

Router(config-if-atm-vc)# tx-ring-limit 5

Router(config-if-atm-vc)# protocol ppp Virtual-Template1

Router(config-if-atm-vc)# pvc 0/37

Router(config-if-atm-vc)# vbr-nrt 800 800

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

Router(config-if-atm-vc)# protocol ppp Virtual-Template2

Router(config-if-atm-vc)# end

Additional References

The following sections provide references related to the ATM Multilink PPP Support on Multiple VCs feature.

Related Documents

Related Topic	Document Title
QoS Configuration Tasks	Cisco IOS Quality of Service Solutions Configuration Guide
QoS Commands List: complete command syntax, defaults, command mode, command history, usage guidelines, and examples.	Cisco IOS Quality of Service Solutions Command Reference
WAN Configuration Tasks	Cisco IOS Wide-Area Networking Configuration Guide
WAN Commands List: complete command syntax, defaults, command mode, command history, usage guidelines, and examples.	Cisco IOS Wide-Area Networking Command Reference
Cisco IOS commands	Cisco IOS Master Commands List, All Releases

Standards

Standard	Title
None	—

MIBs

MIB	MIBs Link
None	To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs

RFCs

RFC	Title
RFC 1990	The PPP Multilink Protocol (MP)

Technical Assistance

Description

Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

Feature Information for ATM Multilink PPP Support on Multiple VCs

Table 1 lists the release history for this feature.

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

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Note Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.

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Table 1 Feature Information for ATM Multilink PPP Support on Multiple VCs

Feature Name	Releases	Feature Information
ATM Multilink PPP Support on Multiple VCs	12.2(28)SB 12.2(13)T 12.2(33)SRE	The ATM Multilink PPP Support on Multiple VCs feature facilitates traffic load balancing on high-speed virtual circuits, using MLP over Frame Relay and ATM. It facilitates traffic load balancing by using MLP to combine packet datagrams on high-speed VCs, as a means for transporting both the voice and data traffic more efficiently.

Glossary

LFI—link fragmentation and interleaving. Method of fragmenting large packets and then queueing the fragments between small packets.

MLP—multilink PPP.

QoS—quality of service.

VC—virtual circuit.

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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.

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