Contents

Using Multilink PPP over ATM Links

This module contains conceptual information and configuration tasks for using Multilink PPP over ATM links. Multilink PPP is a method that is used to reduce latency and jitter for real-time traffic.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 module.

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.

Prerequisites for Using Multilink PPP over ATM Links

  • Be familiar with the concepts in the "Reducing Latency and Jitter for Real-Time Traffic Using Multilink PPP" module.

  • Multilink PPP uses first-in first-out (FIFO) queueing for queueing and interleaving packets. Other queueing mechanisms such as low latency queueing (LLQ), weighted fair queueing (WFQ), and class-based weighted fair queueing (CBWFQ) can be used. If you want to use one of these alternative mechanisms, enable it before configuring Multilink.

Restrictions for Using Multilink PPP over ATM Links

  • Only Voice over IP (VoIP) is supported; Voice over ATM is not supported.

  • Multilink PPP over ATM must use the following ATM network modules:
    • Multiport T1/E1 ATM Network Module with Inverse Multiplexing over ATM
    • ATM OC-3 Network Module
    • Enhanced ATM Port Adapter

Information About Using Multilink PPP over ATM Links

MQC and Multilink PPP over ATM Links

Before using Multilink PPP over ATM links, a policy map must be created. (See the "Prerequisites" section on page 6 .) Policy maps are created using the Modular Quality of Service (QoS) Command-Line Interface (CLI) (MQC).

VirtualTemplateInterfaces

A virtual template interface is a logical interface that is configured with generic configuration information for a specific purpose or a configuration common to specific users, plus router-dependent information. The template takes the form of a list of Cisco IOS interface commands that are applied to virtual access interfaces, as needed.

Multilink Group Interfaces

A multilink group interface is a collection of interfaces that are bundled together in the multilink PPP configuration. With a multilink group interface, you can bundle interfaces into logical multilink groups.

How to Configure Multilink PPP over ATM Links

While the first two procedures are listed as optional, you must choose one or the other according to the Cisco router that you are using in your network.

Configuring Multilink PPP over ATM Links on a Virtual Template Interface

These steps apply if you are using the Cisco 7500 series router or the Cisco 7600 series router only. If you are using another series of Cisco router, do not complete these steps. Instead, advance to the Configuring Multilink PPP over ATM Links on a Multilink Group Interface.

Before You Begin

Before proceeding with this task, you must create a policy map. The policy map contains the configuration parameters used to apply a specific QoS feature, such as distributed LLQ (dLLQ), to the network traffic.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    interface virtual-template number

    4.    bandwidth kbps

    5.    ip address ip-address mask [secondary]

    6.    service-policy output policy-map-name

    7.    service-policy input policy-map-name

    8.    ppp multilink

    9.    ppp multilink fragment delay milliseconds [microseconds]

    10.    ppp multilink interleave

    11.    end


DETAILED STEPS
     Command or ActionPurpose
    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 virtual-template number


    Example:
    Router(config)# interface virtual-template 4
     

    Creates a virtual template and enters interface configuration mode.

    • Enter the virtual template number.

     
    Step 4 bandwidth kbps


    Example:
    Router(config-if)# bandwidth 32
     

    Sets the bandwidth value for an interface.

    • Enter the bandwidth value in kilobits per second.

     
    Step 5 ip address ip-address mask [secondary]


    Example:
    Router(config-if)# ip address 10.10.100.1 255.255.255.0
     

    Sets a primary IP address for an interface. This command can also set the optional secondary IP address for an interface.

    • Enter the primary IP address (and, optionally, the secondary IP address).

     
    Step 6 service-policy output policy-map-name


    Example:
    Router(config-if)# service-policy output policy1
     

    Attaches the previously created QoS traffic policy (policy map). The policy map evaluates and applies QoS features for traffic leaving the interface.

    • Enter the policy map name.

     
    Step 7 service-policy input policy-map-name


    Example:
    Router(config-if)# service-policy input policy1
     

    Attaches the previously created QoS traffic policy (policy map). The policy map evaluates and applies QoS features for traffic enteringthe interface.

    • Enter the policy map name.

     
    Step 8 ppp multilink


    Example:
    Router(config-if)# ppp multilink
     

    Enables Multilink PPP (MLP) on the interface.

     
    Step 9 ppp multilink fragment delay milliseconds [microseconds]


    Example:
    Router(config-if)# ppp multilink fragment delay 20
     

    Specifies a maximum size in units of time for packet fragments on an MLP bundle.

    • Enter the maximum amount of time, in milliseconds.

    Note   

    The fragment delay can be calculated using the following formula:

    fragment delay = (fragment size * 8)/bandwidth

     
    Step 10 ppp multilink interleave


    Example:
    Router(config-if)# ppp multilink interleave
     

    Enables interleaving of packets among the fragments of larger packets on a multilink bundle.

     
    Step 11 end


    Example:
    Router(config-if)# end
     

    (Optional) Exits interface configuration mode and returns to privileged EXEC mode.

     

    Configuring Multilink PPP over ATM Links on a Multilink Group Interface

    If you are using the Cisco 7500 series router or the Cisco 7600 series router, do not complete these steps. Instead, complete the steps in Configuring Multilink PPP over ATM Links on a Virtual Template Interface.

    Before You Begin

    Before proceeding with this task, you must create a policy map. The policy map contains the configuration parameters used to apply a specific QoS feature, such as distributed LLQ (dLLQ), to the network traffic.

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    interface multilink multilink-bundle-number

      4.    ip address ip-address mask [secondary]

      5.    service-policy output policy-map-name

      6.    service-policy input policy-map-name

      7.    ppp multilink fragment delay milliseconds [microseconds]

      8.    ppp multilink interleave

      9.    ppp multilink multiclass

      10.    end


    DETAILED STEPS
       Command or ActionPurpose
      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 multilink multilink-bundle-number


      Example:
      Router(config)# interface multilink 1
       

      Creates a multilink bundle and enters interface configuration mode.

      • Enter the multilink bundle number.

       
      Step 4 ip address ip-address mask [secondary]


      Example:
      Router(config-if)# ip address 10.10.100.1 255.255.255.0
       

      Sets a primary IP address for an interface. This command can also set the optional secondary IP address for an interface.

      • Enter the primary IP address (and, optionally, the secondary IP address).

       
      Step 5 service-policy output policy-map-name


      Example:
      Router(config-if)# service-policy output policy1
       

      Attaches the previously created QoS traffic policy (policy map). See the "Prerequisites" section on page 3 . The policy map evaluates and applies QoS features for traffic leaving the interface.

      • Enter the policy map name.

       
      Step 6 service-policy input policy-map-name


      Example:
      Router(config-if)# service-policy input policy1
       

      Attaches the previously created QoS traffic policy (policy map). See the "Prerequisites" section on page 3 . The policy map evaluates and applies QoS features for traffic enteringthe interface.

      • Enter the policy map name.

       
      Step 7 ppp multilink fragment delay milliseconds [microseconds]


      Example:
      Router(config-if)# ppp multilink fragment delay 20
       

      Specifies a maximum size in units of time for packet fragments on a Multilink PPP (MLP) bundle.

      • Enter the maximum amount of time, in milliseconds.

       
      Step 8 ppp multilink interleave


      Example:
      Router(config-if)# ppp multilink interleave
       

      Enables interleaving of packets among the fragments of larger packets on a multilink bundle.

       
      Step 9 ppp multilink multiclass


      Example:
      Router(config-if)# ppp multilink multiclass
       

      (Optional) Enables Multiclass Multilink PPP (MCMP) on an interface.

      Note   

      Use this command only if there are multiple links in the multilink bundle.

       
      Step 10 end


      Example:
      Router(config-if)# end
       

      (Optional) Exits interface configuration mode and returns to privileged EXEC mode.

       

      What to Do Next

      After configuring Multilink PPP over ATM links on a multilink group interface, the next step is to associate the virtual template interface with the multilink group by completing the steps in the following section.

      If you are using a Cisco 7500 series router or a Cisco 7600 series router, advance to the Associating the Virtual Template Interface with an ATM PVC to continue.

      Associating the Virtual Template Interface with the Multilink Group

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    interface virtual-template number

        4.    no ip address [ip-address mask [secondary]]

        5.    ppp multilink group group-number

        6.    end


      DETAILED STEPS
         Command or ActionPurpose
        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 virtual-template number


        Example:
        Router(config)# interface virtual-template 2
         

        Creates a virtual template interface that can be configured and applied dynamically in creating virtual access interfaces, and enters interface configuration mode.

        • Enter the number used to identify the virtual template interface.

         
        Step 4 no ip address [ip-address mask [secondary]]


        Example:
        Router(config-if)# no ip address
         

        Removes an IP address or disables IP processing.

         
        Step 5 ppp multilink group group-number


        Example:
        Router(config-if)# ppp multilink group 1
         

        Restricts a physical link to joining only a designated multilink group interface.

        • Enter the multilink group number.

         
        Step 6 end


        Example:
        Router(config-if)# end
         

        (Optional) Exits interface configuration mode and returns to privileged EXEC mode.

         

        Associating the Virtual Template Interface with an ATM PVC

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    interface type number [name-tag]

          4.    pvc [name] vpi / vci [ces | ilmi | qsaal | smds | l2transport]

          5.    abr output-pcr output-mcr

          6.    vbr-nrt output-pcr output-scr output-mbs [input-pcr] [input-scr] [input-mbs]

          7.    protocol ppp virtual-template number

          8.    end


        DETAILED STEPS
           Command or ActionPurpose
          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 [name-tag]


          Example:
          Router(config)# interface atm2/0/0
           

          Configures an interface type and enters interface configuration mode.

          • Enter the interface type and number.

           
          Step 4 pvc [name] vpi / vci [ces | ilmi | qsaal | smds | l2transport]


          Example:
          Router(config-if)# pvc cisco 0/16
           

          Creates or assigns a name to an ATM permanent virtual circuit (PVC) and enters ATM virtual circuit configuration mode.

          • Enter the ATM PVC name, the network virtual path identifier, and the network virtual channel identifier.

           
          Step 5 abr output-pcr output-mcr


          Example:
          Router(config-if-atm-vc)# abr 100 80
           

          (Optional) Selects available bit rate (ABR) QoS and configures the output peak cell rate (PCR) and output minimum guaranteed cell rate (MCR) for an ATM PVC.

          • Enter the output PCR and the output MCR.

           
          Step 6 vbr-nrt output-pcr output-scr output-mbs [input-pcr] [input-scr] [input-mbs]


          Example:
          Router(config-if-atm-vc)# vbr-nrt 1100 1100 100
           

          (Optional) Configures the variable bit rate-nonreal time (VBR-NRT) quality of service (QoS) and specifies the output peak cell rate (PCR), the output sustainable cell rate (SCR), and the output maximum burst cell size (MBS) for an ATM PVC, PVC range, switched virtual circuit (SVC), VC class, or VC bundle member.

          • Enter the output PCR, SCR, and MBS.

           
          Step 7 protocol ppp virtual-template number


          Example:
          Router(config-if-atm-vc)# protocol ppp virtual-template 2
           

          Specifies that PPP is established over the ATM PVC using the configuration from the specified virtual template.

          • Enter the virtual-template number.

           
          Step 8 end


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

          (Optional) Exits ATM virtual circuit configuration mode and returns to privileged EXEC mode.

           

          Verifying the Multilink PPP over ATM Links Configuration

          SUMMARY STEPS

            1.    enable

            2.    show atm pvc [vpi / vci | name | interface atm interface-number[. subinterface-number multipoint]] [ppp]

            3.    show interfaces [type number] [first] [last] [accounting]

            4.    show ppp multilink [active | inactive | interface bundle-interface | [username name] [endpoint endpoint]]

            5.    show policy-map interface interface-name [vc [vpi /] vci] [dlci dlci] [input | output]

            6.    exit


          DETAILED STEPS
             Command or ActionPurpose
            Step 1 enable


            Example:
            Router> enable
             

            Enables privileged EXEC mode.

            • Enter your password if prompted.

             
            Step 2 show atm pvc [vpi / vci | name | interface atm interface-number[. subinterface-number multipoint]] [ppp]


            Example:
            Router# show atm pvc
             

            (Optional) Displays all ATM PVCs and traffic information.

             
            Step 3 show interfaces [type number] [first] [last] [accounting]


            Example:
            Router# show interfaces
             

            (Optional) Displays statistics for all interfaces that are configured on the router or access server.

             
            Step 4 show ppp multilink [active | inactive | interface bundle-interface | [username name] [endpoint endpoint]]


            Example:
            Router# show ppp multilink
             

            (Optional) Displays bundle information for multilink bundles.

             
            Step 5 show policy-map interface interface-name [vc [vpi /] vci] [dlci dlci] [input | output]


            Example:
            Router# show policy-map interface serial0/0
             

            (Optional) Displays the packet statistics of all classes that are configured for all service policies either on the specified interface or subinterface or on a specific PVC on the interface.

             
            Step 6 exit


            Example:
            Router# exit
             

            (Optional) Exits privileged EXEC mode.

             

            Configuration Examples for Using Multilink PPP over ATM Links

            Example Configuring Multilink PPP over ATM Links on a Virtual Template Interface

            The following is an example of configuring Multilink PPP over ATM links on a virtual template interface:

            Router> enable
            Router# configure terminal
            Router(config)# interface virtual-template 4
            Router(config-if)# bandwidth 32
            Router(config-if)# ip address 10.10.100.1 255.255.255.0
 
            Router(config-if)# service-policy output policy1
            Router(config-if)# service-policy input policy1
            Router(config-if)# ppp multilink 
            Router(config-if)# ppp multilink fragment delay 20 
            Router(config-if)# ppp multilink interleave 
            Router(config-if)# end

            Example Configuring Multilink PPP over ATM Links on a Multilink Group Interface

            The following is an example of configuring Multilink PPP over ATM links on a multilink group interface:

            Router> enable
            Router# configure terminal
            Router(config)# interface multilink 1
            Router(config-if)# ip address 10.10.100.1 255.255.255.0
 
            Router(config-if)# service-policy output policy1
            Router(config-if)# service-policy input policy1
            Router(config-if)# ppp multilink fragment delay 20 
            Router(config-if)# ppp multilink interleave 
            Router(config-if)# ppp multilink multiclass
            Router(config-if)# end

            Example Associating the Virtual Template Interface with the Multilink Group

            The following is an example of associating the virtual template interface with the multilink group:

            Router> enable
            Router# configure terminal
            Router(config)# interface virtual-template 2
            Router(config-if)# no ip address
            Router(config-if)# ppp multilink group 1
            Router(config-if)# end

            Example Associating the Virtual Template Interface with an ATM PVC

            The following is an example of associating the virtual template interface with an ATM PVC:

            Router> enable
            Router# configure terminal
            Router(config)# interface atm2/0/0
            Router(config-if)# pvc cisco 0/16
            Router(config-if-atm-vc)# abr 100 80
            Router(config-if-atm-vc)# protocol ppp virtual-template 2
            Router(config-if-atm-vc)# end

            Example Verifying the Multilink PPP over ATM Links Configuration

            The following is an example of the show ppp multilink command output. In this example, one multilink bundle called 7206-2 is on the system. This bundle has two member links: one active link and one inactive link.

            Router# show ppp multilink
Multilink1, bundle name is 7206-2
  Endpoint discriminator is 7206-2
  Bundle up for 00:00:24, 1/255 load
  Receive buffer limit 12000 bytes, frag timeout 1000 ms
    0/0 fragments/bytes in reassembly list
    0 lost fragments, 0 reordered
    0/0 discarded fragments/bytes, 0 lost received
    0x0 received sequence, 0x0 sent sequence
  Member links: 1 active, 1 inactive (max not set, min not set)
    Vi3, since 00:00:24
    PPPoATM link, ATM PVC 2/101 on ATM2/0/0
    Packets in ATM PVC Holdq: 0 , Particles in ATM PVC Tx Ring: 1
    Vt1 (inactive)

            Where to Go Next

            To use Multilink PPP over Frame Relay, see the "Using Multilink PPP over Frame Relay" module.

            To use Multilink PPP over dialer interface links, see the "Using Multilink PPP over Dialer Interface Links" module.

            To use Multilink PPP over serial interface links, see the "Using Multilink PPP over Serial Interface Links" module.

            Additional References

            The following sections provide references related to using Multilink PPP over ATM links.

            Related Documents

            Related Topic

            Document Title

            QoS commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

            Cisco IOS Quality of Service Solutions Command Reference

            LLQ, WFQ, CBWFQ, PQ, CQ, FIFO, and other queueing mechanisms

            "Configuring Weighted Fair Queueing" module

            MQC

            "Applying QoS Features Using the MQC" module

            Multilink PPP configurations

            "Configuring Media-Independent PPP and Multilink PPP" module

            Virtual template interfaces

            "Configuring Virtual Template Interfaces" module

            Multilink PPP overview module

            "Reducing Latency and Jitter for Real-Time Traffic Using Multilink PPP" module

            Multilink PPP over Frame Relay

            "Using Multilink PPP over Frame Relay" module

            Multilink PPP over dialer interface links

            "Using Multilink PPP over Dialer Interface Links" module

            Multilink PPP over serial interface links

            "Using Multilink PPP over Serial Interface Links" module

            Standards

            Standard

            Title

            No new or modified standards are supported, and support for existing standards has not been modified.

            --

            MIBs

            MIB

            MIBs Link

            No new or modified MIBs are supported, and support for existing MIBs has not been modified.

            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)

            RFC 2686

            Multiclass Extension to Multilink PPP (MCML)

            Technical Assistance

            Description

            Link

            The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

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

            Feature Information for Using Multilink PPP over ATM Links

            The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

            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.

            Table 1 Feature Information for Using Multilink PPP over ATM Links

            Feature Name

            Releases

            Feature Information

            Distributed Link Fragmentation and Interleaving for Frame Relay and ATM Interfaces on Cisco 7500 Series Routers

            12.2(4)T

            The Distributed Link Fragmentation and Interleaving (dLFI) for Frame Relay and ATM Interfaces on Cisco 7500 Series Routers feature extends link fragmentation and interleaving functionality to VIP-enabled Cisco 7500 series routers.

            This feature was extensively rewritten from the perspective of using Multilink PPP for link fragmentation and interleaving over ATM interface links.

            Distributed Link Fragmentation and Interleaving over Leased Lines

            12.2(8)T

            The Distributed Link Fragmentation and Interleaving over Leased Lines feature extends distributed link fragmentation and interleaving functionality to leased lines.

            This feature was extensively rewritten from the perspective of using Multilink PPP for link fragmentation and interleaving over ATM interface links.

            MLP LFI over ATM Configuration Scaling

            12.2(25)S 12.2(27)SBA 15.0(1)M

            The MLP LFI over ATM Configuration Scaling feature supports the transport of real-time (voice) and non-real-time (data) traffic on lower-speed Frame Relay and ATM permanent virtual circuits (PVCs) without causing excessive delay of real-time traffic.

            The following commands were introduced or modified: ppp multilink group

            Using Multilink PPP over ATM Links

            Contents

            Using Multilink PPP over ATM Links

            This module contains conceptual information and configuration tasks for using Multilink PPP over ATM links. Multilink PPP is a method that is used to reduce latency and jitter for real-time traffic.

            Finding Feature Information

            Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 module.

            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.

            Prerequisites for Using Multilink PPP over ATM Links

            • Be familiar with the concepts in the "Reducing Latency and Jitter for Real-Time Traffic Using Multilink PPP" module.

            • Multilink PPP uses first-in first-out (FIFO) queueing for queueing and interleaving packets. Other queueing mechanisms such as low latency queueing (LLQ), weighted fair queueing (WFQ), and class-based weighted fair queueing (CBWFQ) can be used. If you want to use one of these alternative mechanisms, enable it before configuring Multilink.

            Restrictions for Using Multilink PPP over ATM Links

            • Only Voice over IP (VoIP) is supported; Voice over ATM is not supported.

            • Multilink PPP over ATM must use the following ATM network modules:
              • Multiport T1/E1 ATM Network Module with Inverse Multiplexing over ATM
              • ATM OC-3 Network Module
              • Enhanced ATM Port Adapter

            Information About Using Multilink PPP over ATM Links

            MQC and Multilink PPP over ATM Links

            Before using Multilink PPP over ATM links, a policy map must be created. (See the "Prerequisites" section on page 6 .) Policy maps are created using the Modular Quality of Service (QoS) Command-Line Interface (CLI) (MQC).

            VirtualTemplateInterfaces

            A virtual template interface is a logical interface that is configured with generic configuration information for a specific purpose or a configuration common to specific users, plus router-dependent information. The template takes the form of a list of Cisco IOS interface commands that are applied to virtual access interfaces, as needed.

            Multilink Group Interfaces

            A multilink group interface is a collection of interfaces that are bundled together in the multilink PPP configuration. With a multilink group interface, you can bundle interfaces into logical multilink groups.

            How to Configure Multilink PPP over ATM Links

            While the first two procedures are listed as optional, you must choose one or the other according to the Cisco router that you are using in your network.

            Configuring Multilink PPP over ATM Links on a Virtual Template Interface

            These steps apply if you are using the Cisco 7500 series router or the Cisco 7600 series router only. If you are using another series of Cisco router, do not complete these steps. Instead, advance to the Configuring Multilink PPP over ATM Links on a Multilink Group Interface.

            Before You Begin

            Before proceeding with this task, you must create a policy map. The policy map contains the configuration parameters used to apply a specific QoS feature, such as distributed LLQ (dLLQ), to the network traffic.

            SUMMARY STEPS

              1.    enable

              2.    configure terminal

              3.    interface virtual-template number

              4.    bandwidth kbps

              5.    ip address ip-address mask [secondary]

              6.    service-policy output policy-map-name

              7.    service-policy input policy-map-name

              8.    ppp multilink

              9.    ppp multilink fragment delay milliseconds [microseconds]

              10.    ppp multilink interleave

              11.    end


            DETAILED STEPS
               Command or ActionPurpose
              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 virtual-template number


              Example:
              Router(config)# interface virtual-template 4
               

              Creates a virtual template and enters interface configuration mode.

              • Enter the virtual template number.

               
              Step 4 bandwidth kbps


              Example:
              Router(config-if)# bandwidth 32
               

              Sets the bandwidth value for an interface.

              • Enter the bandwidth value in kilobits per second.

               
              Step 5 ip address ip-address mask [secondary]


              Example:
              Router(config-if)# ip address 10.10.100.1 255.255.255.0
               

              Sets a primary IP address for an interface. This command can also set the optional secondary IP address for an interface.

              • Enter the primary IP address (and, optionally, the secondary IP address).

               
              Step 6 service-policy output policy-map-name


              Example:
              Router(config-if)# service-policy output policy1
               

              Attaches the previously created QoS traffic policy (policy map). The policy map evaluates and applies QoS features for traffic leaving the interface.

              • Enter the policy map name.

               
              Step 7 service-policy input policy-map-name


              Example:
              Router(config-if)# service-policy input policy1
               

              Attaches the previously created QoS traffic policy (policy map). The policy map evaluates and applies QoS features for traffic enteringthe interface.

              • Enter the policy map name.

               
              Step 8 ppp multilink


              Example:
              Router(config-if)# ppp multilink
               

              Enables Multilink PPP (MLP) on the interface.

               
              Step 9 ppp multilink fragment delay milliseconds [microseconds]


              Example:
              Router(config-if)# ppp multilink fragment delay 20
               

              Specifies a maximum size in units of time for packet fragments on an MLP bundle.

              • Enter the maximum amount of time, in milliseconds.

              Note   

              The fragment delay can be calculated using the following formula:

              fragment delay = (fragment size * 8)/bandwidth

               
              Step 10 ppp multilink interleave


              Example:
              Router(config-if)# ppp multilink interleave
               

              Enables interleaving of packets among the fragments of larger packets on a multilink bundle.

               
              Step 11 end


              Example:
              Router(config-if)# end
               

              (Optional) Exits interface configuration mode and returns to privileged EXEC mode.

               

              Configuring Multilink PPP over ATM Links on a Multilink Group Interface

              If you are using the Cisco 7500 series router or the Cisco 7600 series router, do not complete these steps. Instead, complete the steps in Configuring Multilink PPP over ATM Links on a Virtual Template Interface.

              Before You Begin

              Before proceeding with this task, you must create a policy map. The policy map contains the configuration parameters used to apply a specific QoS feature, such as distributed LLQ (dLLQ), to the network traffic.

              SUMMARY STEPS

                1.    enable

                2.    configure terminal

                3.    interface multilink multilink-bundle-number

                4.    ip address ip-address mask [secondary]

                5.    service-policy output policy-map-name

                6.    service-policy input policy-map-name

                7.    ppp multilink fragment delay milliseconds [microseconds]

                8.    ppp multilink interleave

                9.    ppp multilink multiclass

                10.    end


              DETAILED STEPS
                 Command or ActionPurpose
                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 multilink multilink-bundle-number


                Example:
                Router(config)# interface multilink 1
                 

                Creates a multilink bundle and enters interface configuration mode.

                • Enter the multilink bundle number.

                 
                Step 4 ip address ip-address mask [secondary]


                Example:
                Router(config-if)# ip address 10.10.100.1 255.255.255.0
                 

                Sets a primary IP address for an interface. This command can also set the optional secondary IP address for an interface.

                • Enter the primary IP address (and, optionally, the secondary IP address).

                 
                Step 5 service-policy output policy-map-name


                Example:
                Router(config-if)# service-policy output policy1
                 

                Attaches the previously created QoS traffic policy (policy map). See the "Prerequisites" section on page 3 . The policy map evaluates and applies QoS features for traffic leaving the interface.

                • Enter the policy map name.

                 
                Step 6 service-policy input policy-map-name


                Example:
                Router(config-if)# service-policy input policy1
                 

                Attaches the previously created QoS traffic policy (policy map). See the "Prerequisites" section on page 3 . The policy map evaluates and applies QoS features for traffic enteringthe interface.

                • Enter the policy map name.

                 
                Step 7 ppp multilink fragment delay milliseconds [microseconds]


                Example:
                Router(config-if)# ppp multilink fragment delay 20
                 

                Specifies a maximum size in units of time for packet fragments on a Multilink PPP (MLP) bundle.

                • Enter the maximum amount of time, in milliseconds.

                 
                Step 8 ppp multilink interleave


                Example:
                Router(config-if)# ppp multilink interleave
                 

                Enables interleaving of packets among the fragments of larger packets on a multilink bundle.

                 
                Step 9 ppp multilink multiclass


                Example:
                Router(config-if)# ppp multilink multiclass
                 

                (Optional) Enables Multiclass Multilink PPP (MCMP) on an interface.

                Note   

                Use this command only if there are multiple links in the multilink bundle.

                 
                Step 10 end


                Example:
                Router(config-if)# end
                 

                (Optional) Exits interface configuration mode and returns to privileged EXEC mode.

                 

                What to Do Next

                After configuring Multilink PPP over ATM links on a multilink group interface, the next step is to associate the virtual template interface with the multilink group by completing the steps in the following section.

                If you are using a Cisco 7500 series router or a Cisco 7600 series router, advance to the Associating the Virtual Template Interface with an ATM PVC to continue.

                Associating the Virtual Template Interface with the Multilink Group

                SUMMARY STEPS

                  1.    enable

                  2.    configure terminal

                  3.    interface virtual-template number

                  4.    no ip address [ip-address mask [secondary]]

                  5.    ppp multilink group group-number

                  6.    end


                DETAILED STEPS
                   Command or ActionPurpose
                  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 virtual-template number


                  Example:
                  Router(config)# interface virtual-template 2
                   

                  Creates a virtual template interface that can be configured and applied dynamically in creating virtual access interfaces, and enters interface configuration mode.

                  • Enter the number used to identify the virtual template interface.

                   
                  Step 4 no ip address [ip-address mask [secondary]]


                  Example:
                  Router(config-if)# no ip address
                   

                  Removes an IP address or disables IP processing.

                   
                  Step 5 ppp multilink group group-number


                  Example:
                  Router(config-if)# ppp multilink group 1
                   

                  Restricts a physical link to joining only a designated multilink group interface.

                  • Enter the multilink group number.

                   
                  Step 6 end


                  Example:
                  Router(config-if)# end
                   

                  (Optional) Exits interface configuration mode and returns to privileged EXEC mode.

                   

                  Associating the Virtual Template Interface with an ATM PVC

                  SUMMARY STEPS

                    1.    enable

                    2.    configure terminal

                    3.    interface type number [name-tag]

                    4.    pvc [name] vpi / vci [ces | ilmi | qsaal | smds | l2transport]

                    5.    abr output-pcr output-mcr

                    6.    vbr-nrt output-pcr output-scr output-mbs [input-pcr] [input-scr] [input-mbs]

                    7.    protocol ppp virtual-template number

                    8.    end


                  DETAILED STEPS
                     Command or ActionPurpose
                    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 [name-tag]


                    Example:
                    Router(config)# interface atm2/0/0
                     

                    Configures an interface type and enters interface configuration mode.

                    • Enter the interface type and number.

                     
                    Step 4 pvc [name] vpi / vci [ces | ilmi | qsaal | smds | l2transport]


                    Example:
                    Router(config-if)# pvc cisco 0/16
                     

                    Creates or assigns a name to an ATM permanent virtual circuit (PVC) and enters ATM virtual circuit configuration mode.

                    • Enter the ATM PVC name, the network virtual path identifier, and the network virtual channel identifier.

                     
                    Step 5 abr output-pcr output-mcr


                    Example:
                    Router(config-if-atm-vc)# abr 100 80
                     

                    (Optional) Selects available bit rate (ABR) QoS and configures the output peak cell rate (PCR) and output minimum guaranteed cell rate (MCR) for an ATM PVC.

                    • Enter the output PCR and the output MCR.

                     
                    Step 6 vbr-nrt output-pcr output-scr output-mbs [input-pcr] [input-scr] [input-mbs]


                    Example:
                    Router(config-if-atm-vc)# vbr-nrt 1100 1100 100
                     

                    (Optional) Configures the variable bit rate-nonreal time (VBR-NRT) quality of service (QoS) and specifies the output peak cell rate (PCR), the output sustainable cell rate (SCR), and the output maximum burst cell size (MBS) for an ATM PVC, PVC range, switched virtual circuit (SVC), VC class, or VC bundle member.

                    • Enter the output PCR, SCR, and MBS.

                     
                    Step 7 protocol ppp virtual-template number


                    Example:
                    Router(config-if-atm-vc)# protocol ppp virtual-template 2
                     

                    Specifies that PPP is established over the ATM PVC using the configuration from the specified virtual template.

                    • Enter the virtual-template number.

                     
                    Step 8 end


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

                    (Optional) Exits ATM virtual circuit configuration mode and returns to privileged EXEC mode.

                     

                    Verifying the Multilink PPP over ATM Links Configuration

                    SUMMARY STEPS

                      1.    enable

                      2.    show atm pvc [vpi / vci | name | interface atm interface-number[. subinterface-number multipoint]] [ppp]

                      3.    show interfaces [type number] [first] [last] [accounting]

                      4.    show ppp multilink [active | inactive | interface bundle-interface | [username name] [endpoint endpoint]]

                      5.    show policy-map interface interface-name [vc [vpi /] vci] [dlci dlci] [input | output]

                      6.    exit


                    DETAILED STEPS
                       Command or ActionPurpose
                      Step 1 enable


                      Example:
                      Router> enable
                       

                      Enables privileged EXEC mode.

                      • Enter your password if prompted.

                       
                      Step 2 show atm pvc [vpi / vci | name | interface atm interface-number[. subinterface-number multipoint]] [ppp]


                      Example:
                      Router# show atm pvc
                       

                      (Optional) Displays all ATM PVCs and traffic information.

                       
                      Step 3 show interfaces [type number] [first] [last] [accounting]


                      Example:
                      Router# show interfaces
                       

                      (Optional) Displays statistics for all interfaces that are configured on the router or access server.

                       
                      Step 4 show ppp multilink [active | inactive | interface bundle-interface | [username name] [endpoint endpoint]]


                      Example:
                      Router# show ppp multilink
                       

                      (Optional) Displays bundle information for multilink bundles.

                       
                      Step 5 show policy-map interface interface-name [vc [vpi /] vci] [dlci dlci] [input | output]


                      Example:
                      Router# show policy-map interface serial0/0
                       

                      (Optional) Displays the packet statistics of all classes that are configured for all service policies either on the specified interface or subinterface or on a specific PVC on the interface.

                       
                      Step 6 exit


                      Example:
                      Router# exit
                       

                      (Optional) Exits privileged EXEC mode.

                       

                      Configuration Examples for Using Multilink PPP over ATM Links

                      Example Configuring Multilink PPP over ATM Links on a Virtual Template Interface

                      The following is an example of configuring Multilink PPP over ATM links on a virtual template interface:

                      Router> enable
                      Router# configure terminal
                      Router(config)# interface virtual-template 4
                      Router(config-if)# bandwidth 32
                      Router(config-if)# ip address 10.10.100.1 255.255.255.0
 
                      Router(config-if)# service-policy output policy1
                      Router(config-if)# service-policy input policy1
                      Router(config-if)# ppp multilink 
                      Router(config-if)# ppp multilink fragment delay 20 
                      Router(config-if)# ppp multilink interleave 
                      Router(config-if)# end

                      Example Configuring Multilink PPP over ATM Links on a Multilink Group Interface

                      The following is an example of configuring Multilink PPP over ATM links on a multilink group interface:

                      Router> enable
                      Router# configure terminal
                      Router(config)# interface multilink 1
                      Router(config-if)# ip address 10.10.100.1 255.255.255.0
 
                      Router(config-if)# service-policy output policy1
                      Router(config-if)# service-policy input policy1
                      Router(config-if)# ppp multilink fragment delay 20 
                      Router(config-if)# ppp multilink interleave 
                      Router(config-if)# ppp multilink multiclass
                      Router(config-if)# end

                      Example Associating the Virtual Template Interface with the Multilink Group

                      The following is an example of associating the virtual template interface with the multilink group:

                      Router> enable
                      Router# configure terminal
                      Router(config)# interface virtual-template 2
                      Router(config-if)# no ip address
                      Router(config-if)# ppp multilink group 1
                      Router(config-if)# end

                      Example Associating the Virtual Template Interface with an ATM PVC

                      The following is an example of associating the virtual template interface with an ATM PVC:

                      Router> enable
                      Router# configure terminal
                      Router(config)# interface atm2/0/0
                      Router(config-if)# pvc cisco 0/16
                      Router(config-if-atm-vc)# abr 100 80
                      Router(config-if-atm-vc)# protocol ppp virtual-template 2
                      Router(config-if-atm-vc)# end

                      Example Verifying the Multilink PPP over ATM Links Configuration

                      The following is an example of the show ppp multilink command output. In this example, one multilink bundle called 7206-2 is on the system. This bundle has two member links: one active link and one inactive link.

                      Router# show ppp multilink
Multilink1, bundle name is 7206-2
  Endpoint discriminator is 7206-2
  Bundle up for 00:00:24, 1/255 load
  Receive buffer limit 12000 bytes, frag timeout 1000 ms
    0/0 fragments/bytes in reassembly list
    0 lost fragments, 0 reordered
    0/0 discarded fragments/bytes, 0 lost received
    0x0 received sequence, 0x0 sent sequence
  Member links: 1 active, 1 inactive (max not set, min not set)
    Vi3, since 00:00:24
    PPPoATM link, ATM PVC 2/101 on ATM2/0/0
    Packets in ATM PVC Holdq: 0 , Particles in ATM PVC Tx Ring: 1
    Vt1 (inactive)

                      Where to Go Next

                      To use Multilink PPP over Frame Relay, see the "Using Multilink PPP over Frame Relay" module.

                      To use Multilink PPP over dialer interface links, see the "Using Multilink PPP over Dialer Interface Links" module.

                      To use Multilink PPP over serial interface links, see the "Using Multilink PPP over Serial Interface Links" module.

                      Additional References

                      The following sections provide references related to using Multilink PPP over ATM links.

                      Related Documents

                      Related Topic

                      Document Title

                      QoS commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

                      Cisco IOS Quality of Service Solutions Command Reference

                      LLQ, WFQ, CBWFQ, PQ, CQ, FIFO, and other queueing mechanisms

                      "Configuring Weighted Fair Queueing" module

                      MQC

                      "Applying QoS Features Using the MQC" module

                      Multilink PPP configurations

                      "Configuring Media-Independent PPP and Multilink PPP" module

                      Virtual template interfaces

                      "Configuring Virtual Template Interfaces" module

                      Multilink PPP overview module

                      "Reducing Latency and Jitter for Real-Time Traffic Using Multilink PPP" module

                      Multilink PPP over Frame Relay

                      "Using Multilink PPP over Frame Relay" module

                      Multilink PPP over dialer interface links

                      "Using Multilink PPP over Dialer Interface Links" module

                      Multilink PPP over serial interface links

                      "Using Multilink PPP over Serial Interface Links" module

                      Standards

                      Standard

                      Title

                      No new or modified standards are supported, and support for existing standards has not been modified.

                      --

                      MIBs

                      MIB

                      MIBs Link

                      No new or modified MIBs are supported, and support for existing MIBs has not been modified.

                      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)

                      RFC 2686

                      Multiclass Extension to Multilink PPP (MCML)

                      Technical Assistance

                      Description

                      Link

                      The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

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

                      Feature Information for Using Multilink PPP over ATM Links

                      The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

                      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.

                      Table 1 Feature Information for Using Multilink PPP over ATM Links

                      Feature Name

                      Releases

                      Feature Information

                      Distributed Link Fragmentation and Interleaving for Frame Relay and ATM Interfaces on Cisco 7500 Series Routers

                      12.2(4)T

                      The Distributed Link Fragmentation and Interleaving (dLFI) for Frame Relay and ATM Interfaces on Cisco 7500 Series Routers feature extends link fragmentation and interleaving functionality to VIP-enabled Cisco 7500 series routers.

                      This feature was extensively rewritten from the perspective of using Multilink PPP for link fragmentation and interleaving over ATM interface links.

                      Distributed Link Fragmentation and Interleaving over Leased Lines

                      12.2(8)T

                      The Distributed Link Fragmentation and Interleaving over Leased Lines feature extends distributed link fragmentation and interleaving functionality to leased lines.

                      This feature was extensively rewritten from the perspective of using Multilink PPP for link fragmentation and interleaving over ATM interface links.

                      MLP LFI over ATM Configuration Scaling

                      12.2(25)S 12.2(27)SBA 15.0(1)M

                      The MLP LFI over ATM Configuration Scaling feature supports the transport of real-time (voice) and non-real-time (data) traffic on lower-speed Frame Relay and ATM permanent virtual circuits (PVCs) without causing excessive delay of real-time traffic.

                      The following commands were introduced or modified: ppp multilink group