Contents

Using Multilink PPP over Frame Relay

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

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 Frame Relay

Knowledge

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

Enable Queuing Mechanism

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

Enable FRTS

  • Frame Relay Traffic Shaping (FRTS) must be enabled on the Frame Relay interface.

Restrictions for Using Multilink PPP over Frame Relay

Number of Links per Multilink Bundle

Only one link per multilink bundle is supported.

VoIP Support

Only Voice over IP (VoIP) is supported; Voice over Frame Relay (VoFR) is not supported.

QoS Configuration

Only one PVC is supported per virtual template.

To handle congestion, a shape policy in an MLP over Frame Relay should be configured via a map class and attached to the PVC.

Information About Using Multilink PPP over Frame Relay

Frame Relay Traffic Shaping and Multilink PPP over Frame Relay

Before using Multilink PPP over Frame Relay, FRTS must be enabled.


Note

On the Cisco 7200 and lower series of routers, the frame-relay traffic-shaping command is used to enable FRTS. On the Cisco 7500 and higher series of routers, the Modular Quality of Service (QoS) Command-Line Interface (CLI) (MQC) is used to enable FRTS. For more information about MQC, see the "MQC and Multilink PPP over Frame Relay" section.

FRTS is a Cisco traffic shaping mechanism. A traffic shaping mechanism allows you to regulate (that is, "shape") the packet flow on a network. When you shape traffic, you control the speed of traffic leaving an interface. This way, you can match the flow of the traffic to the speed of the interface and avoid bottlenecks on the network.

Cisco has long provided support for forward explicit congestion notification (FECN) for DECnet and OSI, and backward explicit congestion notification (BECN) for Systems Network Architecture (SNA) traffic using Logical Link Control, type 2 (LLC2) encapsulation via RFC 1490 and discard eligible (DE) bit support. FRTS builds upon this existing Frame Relay support with additional capabilities that improve the scalability and performance of a Frame Relay network, increasing the density of virtual circuits (VCs) and improving response time.

FRTS can eliminate bottlenecks in Frame Relay networks that have high-speed connections at the central site and low-speed connections at branch sites. You can configure rate enforcement--a peak rate configured to limit outbound traffic--to limit the rate at which data is sent on the VC at the central site.

MQC and Multilink PPP over Frame Relay

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

Virtual Template Interfaces

A virtual template interface is logical interface configured with generic configuration information for a specific purpose or 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 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 Frame Relay

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 Frame Relay 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 Configuring Multilink PPP over Frame Relay 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 features such as distributed LLQ (dLLQ) to the network traffic. To create a policy map and configure the appropriate QoS feature, use the MQC. See the MQC and Multilink PPP over Frame Relay.

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 1
     

    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.

    Note   

    The bandwidth value for the interface should match the traffic speed of the PVC; for instance, if the VBR peak cell rate is 128 kbps, the kbps option in the bandwidth command should be entered as 128. Similarly, if the PVC is being shaped to 64 kbps, the kbps option should be entered as 64.

     
    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). See the "Prerequisites" section on page 4 . 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). See the "Prerequisites" section on page 4 . The policy map evaluates and applies QoS features for traffic entering the interface.

    • Enter the policy map name.

     
    Step 8 ppp multilink


    Example:
    Router(config-if)# ppp multilink
     

    Enables 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 a Multilink PPP (MLP) bundle.

    • Enter the maximum amount of time, in milliseconds.

    Note   

    The fragment size can be configured using the following formula: fragment size = bandwidth x fragment-delay / 8

     
    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.

     

    Configuring Multilink PPP over Frame Relay 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 Frame Relay 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 features such as distributed LLQ (dLLQ) to the network traffic. To create a policy map and configure the appropriate QoS feature, use the MQC. See the MQC and Multilink PPP over Frame Relay.

    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.    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 6 . 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 6 . The policy map evaluates and applies QoS features for traffic entering the 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 bundle.

      • Enter the maximum amount of time, in milliseconds, required to transmit a fragment.

       
      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 end


      Example:
      Router(config-if)# end
       

      (Optional) Exits interface configuration mode.

       

      What to Do Next

      After configuring Multilink PPP over Frame Relay 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 Associating the Virtual Template Interface with a Frame Relay 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

        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# interface virtual-template 1
         

        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


        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.

         

        Associating the Virtual Template Interface with a Frame Relay PVC

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    interface type number [name-tag]

          4.    frame-relay traffic-shaping

          5.    frame-relay interface-dlci dlci [ietf | cisco] [voice-cir cir] [ppp virtual-template-name]

          6.    class name

          7.    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 serial1/0/0/1:0
           

          Configures an interface type and enters interface configuration mode.

          • Enter the interface type and number.

           
          Step 4 frame-relay traffic-shaping


          Example:
          Router(config-if)# frame-relay traffic-shaping
           

          Enables both traffic shaping and per-virtual-circuit queueing for all permanent virtual circuits (PVCs) and switched virtual circuits (SVCs) on a Frame Relay interface.

          Note   

          Use this command on Cisco 7200 and lower series routers only . Do not use this command on Cisco 7500 or higher series routers. For Cisco 7500 and higher series routers, use the MQC instead of this command.

           
          Step 5 frame-relay interface-dlci dlci [ietf | cisco] [voice-cir cir] [ppp virtual-template-name]


          Example:
          Router(config-if)# frame-relay interface-dlci 100 ppp virtual-template1
           

          Assigns a data-link connection identifier (DLCI) to a specified Frame Relay subinterface on the router or access server, assigns a specific PVC to a DLCI, or applies a virtual template configuration for a PPP session. Enters Frame Relay DLCI configuration mode.

          • Enter the DLCI number and any optional keywords and arguments, as appropriate.

           
          Step 6 class name


          Example:
          Router(config-fr-dlci)# class frdlci
           

          Associates a map class with a specified DLCI.

          • Enter the name of the map class to associate with the specified DLCI.

          Note   

          Use this command on Cisco 7200 and lower series routers only . For Cisco 7500 and higher series routers, this command is not needed.

           
          Step 7 end


          Example:
          Router(config-fr-dlci)# end
           

          (Optional) Exits Frame Relay DLCI configuration mode.

           

          Verifying the Multilink PPP over Frame Relay Configuration

          SUMMARY STEPS

            1.    enable

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

            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 frame-relay pvc [interface interface] [dlci] [64-bit]


            Example:
            Router# show frame-relay pvc
             

            (Optional) Displays statistics about permanent virtual circuits (PVCs) for Frame Relay interfaces.

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


            Example:
            Router# show interfaces
             

            (Optional) Displays statistics for all interfaces 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 Multilink PPP over Frame Relay

            Example Configuring Multilink PPP over Frame Relay on a Virtual Template Interface

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

            Router> enable
            Router# configure terminal
            Router(config)# interface virtual-template 1
            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 Frame Relay on a Multilink Group Interface

            The following is an example of configuring Multilink PPP over Frame Relay 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)# 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 1
            Router(config-if)# no ip address
            Router(config-if)# ppp multilink group 1
            Router(config-if)# end 
            

    
            

            

            

            Example  Associating the Virtual Template Interface with a Frame Relay PVC
            

            
      
            
The following is an example of associating the virtual template interface with a Frame Relay PVC:
            

      
            Router> enable
            

      
            Router# configure terminal
            

      
            Router(config)# interface serial1/0/0/1:0
            

      
            Router(config-if)# frame-relay interface-dlci 100 ppp virtual-template1 
            

      
            Router(config-fr-dlci)# class frdlci
            

      
            Router(config-fr-dlci)# end 
            

    
            

            

            

            Example Verifying the Multilink PPP over Frame Relay Configuration
            

             
		
             You can verify the Multilink with PPP over Frame Relay configuration by using one or more of the following 
		  show commands:
		
            
 
		
            •  
			  
				show 
				frame 
				relay 
				pvc 
			  
		  
              

              • 

            •  
			  
				show 
				interfaces 
			  
		  
              

              • 

            •  
			  
				show 
				ppp 
				multilink 
			  
		  
              

              • 

            •  
			  
				show 
				policy-map 
				interface 
			  
		  
              

              • 

            
 
		
             The following section provides sample output of the 
		  show 
			 ppp 
			 multilink command only. For sample output of the other commands, see the appropriate Cisco IOS Release 12.3T command reference publication.
		
            
 
	 
            

            show ppp multilink Command Output Example
             
		 
		
             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 00:00:15, 1/255 load
  Receive buffer limit 12000 bytes, frag timeout 3428 ms
    0/0 fragments/bytes in reassembly list
    1 lost fragments, 1 reordered
    0/0 discarded fragments/bytes, 0 lost received
    0x3 received sequence, 0x3 sent sequence
  Member links:1 active, 1 inactive (max not set, min not set)
    Vi2, since 00:00:15, 105 weight, 93 frag size
    Vt1 (inactive)
            
 
	 
            

            

            

            

            Where to Go Next
            

             To use Multilink PPP over ATM links, see the "Using Multilink PPP over ATM Links" 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 Frame Relay. 
		
            
 
	 
            

            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 
					 
            
 
				              		

            

             
					 
             FRTS 
					 
            
 
				              		
 
					 
             "MQC-Based Frame Relay Traffic Shaping" 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 ATM links (including ATM interfaces and ATM PVCs) 
					 
            
 
				              		
 
					 
             "Using Multilink PPP over ATM Links" 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 Frame Relay
            

             
		
            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 Frame Relay
             
				  
             Feature Name 
				  
            
 
				            		
 
				  
             Software Releases 
				  
            
 
				            		
 
				  
             Feature Configuration 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 Frame Relay. 
				  
            
 
				            		

            

             
				  
             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 Frame Relay. 
				  
            
 
				            		

            
            

            

            
 
	 
            

            

            

            


            
















Using Multilink PPP over Frame Relay

                              

            


            Contents
            Using Multilink PPP over Frame Relay
            

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

            

            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 Frame Relay
            

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

              • 

            
 
	 
            

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

              • 

            
 
	 
            

            Enable FRTS
             
		 
		
            •  Frame Relay Traffic Shaping (FRTS) must be enabled on the Frame Relay interface.
		  
              

              • 

            
 
	 
            

            

            

            Restrictions for Using Multilink PPP over Frame Relay
            

            Number of Links per Multilink Bundle
             
		 
		
             Only one link per multilink bundle is supported. 
		
            
 
	 
            

            VoIP Support
             
		 
		
             Only Voice over IP (VoIP) is supported; Voice over Frame Relay (VoFR) is not supported. 
		
            
 
	 
            

             QoS Configuration
             
		 
		
            Only one PVC is supported per virtual template. 
		
            
 
		
            To handle congestion, a shape policy in an MLP over Frame Relay should be configured via a map class and attached to the PVC. 
		
            
 
	 
            

            

            

            Information About Using Multilink PPP over Frame Relay
            

            

            Frame Relay Traffic Shaping and Multilink PPP over Frame Relay
            

             Before using Multilink PPP over Frame Relay, FRTS must be enabled.
	 
            


            Note
             On the Cisco 7200 and lower series of routers, the 
		frame-relay 
		  traffic-shaping command is used to enable FRTS. On the Cisco 7500 and higher series of routers, the Modular Quality of Service (QoS) Command-Line Interface (CLI) (MQC) is used to enable FRTS. For more information about MQC, see the "MQC and Multilink PPP over Frame Relay" section.
	 
            

            

             FRTS is a Cisco traffic shaping mechanism. A traffic shaping mechanism allows you to regulate (that is, "shape") the packet flow on a network. When you shape traffic, you control the speed of traffic leaving an interface. This way, you can match the flow of the traffic to the speed of the interface and avoid bottlenecks on the network. 
	 
            

             Cisco has long provided support for forward explicit congestion notification (FECN) for DECnet and OSI, and backward explicit congestion notification (BECN) for Systems Network Architecture (SNA) traffic using Logical Link Control, type 2 (LLC2) encapsulation via RFC 1490 and discard eligible (DE) bit support. FRTS builds upon this existing Frame Relay support with additional capabilities that improve the scalability and performance of a Frame Relay network, increasing the density of virtual circuits (VCs) and improving response time.
	 
            

             FRTS can eliminate bottlenecks in Frame Relay networks that have high-speed connections at the central site and low-speed connections at branch sites. You can configure rate enforcement--a peak rate configured to limit outbound traffic--to limit the rate at which data is sent on the VC at the central site. 
	 
            

            

            

            MQC and Multilink PPP over Frame Relay
            

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

            

            

            Virtual Template Interfaces
            

             A virtual template interface is logical interface configured with generic configuration information for a specific purpose or 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 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 Frame Relay
            

             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 Frame Relay 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 
		  Configuring Multilink PPP over Frame Relay 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 features such as distributed LLQ (dLLQ) to the network traffic. To create a policy map and configure the appropriate QoS feature, use the MQC. See the 
		  MQC and Multilink PPP over Frame Relay.
		
            
 
	 
            
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 1
              
 
		  
              
 
                    		  
			 
               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.
				
                

                • 

              
 
			 
              Note   
                
              
               The bandwidth value for the interface should match the traffic speed of the PVC; for instance, if the VBR peak cell rate is 128 kbps, the 
				kbps option in the 
				bandwidth command should be entered as 128. Similarly, if the PVC is being shaped to 64 kbps, the 
				kbps option should be entered as 64.
			 
              

              
 
		   
      
              

              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). See the 
				"Prerequisites" section on page 4 
				. 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). See the 
				"Prerequisites" section on page 4 
				. The policy map evaluates and applies QoS features for traffic 
				entering the interface.
			 
              
 
			 
              •  Enter the policy map name.
				
                

                • 

              
 
		   
      
              

              Step 8 
			  
				ppp 
				multilink 
			  
		  
               

              Example:
               
			 
              Router(config-if)# ppp multilink 
              
 
		  
              
 
                    		  
			 
               Enables 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 a Multilink PPP (MLP) bundle.
			 
              
 
			 
              •  Enter the maximum amount of time, in milliseconds.
				
                

                • 

              
 
			 
              Note   
                
              
               The fragment size can be configured using the following formula: fragment size = bandwidth x fragment-delay / 8
			 
              

              
 
		   
      
              

              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. 
			 
              
 
		   
      
              

              

              

              

              Configuring Multilink PPP over Frame Relay 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 Frame Relay 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 features such as distributed LLQ (dLLQ) to the network traffic. To create a policy map and configure the appropriate QoS feature, use the MQC. See the 
		  MQC and Multilink PPP over Frame Relay.
		
              
 
	 
              
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.   
       
			  
				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 6 
				. 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 6 
				. The policy map evaluates and applies QoS features for traffic 
				entering the 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 bundle.
			 
                
 
			 
                •  Enter the maximum amount of time, in milliseconds, required to transmit a fragment.
				
                  

                  • 

                
 
		   
      
                

                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 
			  
				end 
			  
		  
                 

                Example:
                 
			 
                Router(config-if)# end 
                
 
		  
                
 
                      		  
			 
                 (Optional) Exits interface configuration mode. 
			 
                
 
		   
      
                

                

                

                What to Do Next
                

                
After configuring Multilink PPP over Frame Relay 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 Associating the Virtual Template Interface with a Frame Relay 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
          
        
                  

                  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# interface virtual-template 1
                  

        
                  
 
                        		 
          
                  
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
          
        
                   

                  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. 
                  

         
      
                  

                  

                  

                  

                  

                  Associating the Virtual Template Interface with a Frame Relay PVC
                  

                  SUMMARY STEPS
                    1.   
      
          
            enable
          
        
                    

                    2.   
      
          
            configure
          
          
            terminal
          
        
                    

                    3.   
      
          
            interface
          
          
            type
          
          
            number
           [name-tag] 
                    

                    4.   
      
          
            frame-relay
            traffic-shaping
          
        
                    

                    5.   
      
          
            frame-relay
            interface-dlci
          
          
            dlci
           [ietf | cisco] [voice-cir cir] [ppp virtual-template-name] 
                    

                    6.   
      
          
            class
          
          
            name
          
        
                    

                    7.   
      
          
            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 serial1/0/0/1:0
                    

        
                    
 
                          		 
          
                    
Configures an interface type and enters interface configuration mode.
                    

          
                    • 
Enter the interface type and number.
                      

                      • 

                    

         
      
                    

                    Step 4
          
            frame-relay
            traffic-shaping
          
        
                     

                    Example:
                    
          
                    Router(config-if)# frame-relay traffic-shaping
                    

        
                    
 
                          		 
          
                    
Enables both traffic shaping and per-virtual-circuit queueing for all permanent virtual circuits (PVCs) and switched virtual circuits (SVCs) on a Frame Relay interface.
                    

          
                    Note   
                
              
                    
Use this command on Cisco 7200 and lower series routers only
. Do not use this command on Cisco 7500 or higher series routers. For Cisco 7500 and higher series routers, use the MQC instead of this command.
                    

                    

         
      
                    

                    Step 5
          
            frame-relay
            interface-dlci
          
          
            dlci
           [ietf | cisco] [voice-cir cir] [ppp virtual-template-name] 
                     

                    Example:
                    
          
                    Router(config-if)# frame-relay interface-dlci 100 ppp virtual-template1 
                    

        
                    
 
                          		 
          
                    
Assigns a data-link connection identifier (DLCI) to a specified Frame Relay subinterface on the router or access server, assigns a specific PVC to a DLCI, or applies a virtual template configuration for a PPP session. Enters Frame Relay DLCI configuration mode.
                    

          
                    • 
Enter the DLCI number and any optional keywords and arguments, as appropriate.
                      

                      • 

                    

         
      
                    

                    Step 6
          
            class
          
          
            name
          
        
                     

                    Example:
                    
          
                    Router(config-fr-dlci)# class frdlci
                    

        
                    
 
                          		 
          
                    
Associates a map class with a specified DLCI.
                    

          
                    • 
Enter the name of the map class to associate with the specified DLCI. 
                      

                      • 

                    

          
                    Note   
                
              
                    
Use this command on Cisco 7200 and lower series routers only
. For Cisco 7500 and higher series routers, this command is not needed.
                    

                    

         
      
                    

                    Step 7
          
            end
          
        
                     

                    Example:
                    
          
                    Router(config-fr-dlci)# end 
                    

        
                    
 
                          		 
          
                    
(Optional) Exits Frame Relay DLCI configuration mode. 
                    

         
      
                    

                    

                    

                    

                    Verifying the Multilink PPP over Frame Relay Configuration
                    

                    SUMMARY STEPS
                      1.   
       
			  
				enable 
			  
		  
                      

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

                      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 
				frame-relay 
				pvc 
			  [interface 
			 interface] [dlci] [64-bit] 
		  
                       

                      Example:
                       
			 
                      Router# show frame-relay pvc
                      
 
		  
                      
 
                            		  
			 
                       (Optional) Displays statistics about permanent virtual circuits (PVCs) for Frame Relay interfaces.
			 
                      
 
		   
      
                      

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

                      Example:
                       
			 
                      Router# show interfaces
                      
 
		  
                      
 
                            		  
			 
                       (Optional) Displays statistics for all interfaces 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 Multilink PPP over Frame Relay
                      

                       
	 
                      

                      

                      Example Configuring Multilink PPP over Frame Relay on a Virtual Template Interface
                      

                       
		
                       The following is an example of configuring Multilink PPP over Frame Relay on a virtual template interface:
		
                      
 
		
                      Router> enable
                      
 
		
                      Router# configure terminal
                      
 
		
                      Router(config)# interface virtual-template 1
                      
 
		
                      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 Frame Relay on a Multilink Group Interface
                      

                       
		
                       The following is an example of configuring Multilink PPP over Frame Relay 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)# 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 1
                      

      
                      Router(config-if)# no ip address
                      

      
                      Router(config-if)# ppp multilink group 1
                      

      
                      Router(config-if)# end 
                      

      
                      

    
                      

                      

                      

                      Example  Associating the Virtual Template Interface with a Frame Relay PVC
                      

                      
      
                      
The following is an example of associating the virtual template interface with a Frame Relay PVC:
                      

      
                      Router> enable
                      

      
                      Router# configure terminal
                      

      
                      Router(config)# interface serial1/0/0/1:0
                      

      
                      Router(config-if)# frame-relay interface-dlci 100 ppp virtual-template1 
                      

      
                      Router(config-fr-dlci)# class frdlci
                      

      
                      Router(config-fr-dlci)# end 
                      

    
                      

                      

                      

                      Example Verifying the Multilink PPP over Frame Relay Configuration
                      

                       
		
                       You can verify the Multilink with PPP over Frame Relay configuration by using one or more of the following 
		  show commands:
		
                      
 
		
                      •  
			  
				show 
				frame 
				relay 
				pvc 
			  
		  
                        

                        • 

                      •  
			  
				show 
				interfaces 
			  
		  
                        

                        • 

                      •  
			  
				show 
				ppp 
				multilink 
			  
		  
                        

                        • 

                      •  
			  
				show 
				policy-map 
				interface 
			  
		  
                        

                        • 

                      
 
		
                       The following section provides sample output of the 
		  show 
			 ppp 
			 multilink command only. For sample output of the other commands, see the appropriate Cisco IOS Release 12.3T command reference publication.
		
                      
 
	 
                      

                      show ppp multilink Command Output Example
                       
		 
		
                       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 00:00:15, 1/255 load
  Receive buffer limit 12000 bytes, frag timeout 3428 ms
    0/0 fragments/bytes in reassembly list
    1 lost fragments, 1 reordered
    0/0 discarded fragments/bytes, 0 lost received
    0x3 received sequence, 0x3 sent sequence
  Member links:1 active, 1 inactive (max not set, min not set)
    Vi2, since 00:00:15, 105 weight, 93 frag size
    Vt1 (inactive)
                      
 
	 
                      

                      

                      

                      

                      Where to Go Next
                      

                       To use Multilink PPP over ATM links, see the "Using Multilink PPP over ATM Links" 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 Frame Relay. 
		
                      
 
	 
                      

                      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 
					 
                      
 
				                        		

                      

                       
					 
                       FRTS 
					 
                      
 
				                        		
 
					 
                       "MQC-Based Frame Relay Traffic Shaping" 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 ATM links (including ATM interfaces and ATM PVCs) 
					 
                      
 
				                        		
 
					 
                       "Using Multilink PPP over ATM Links" 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 Frame Relay
                      

                       
		
                      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 Frame Relay
                       
				  
                       Feature Name 
				  
                      
 
				                      		
 
				  
                       Software Releases 
				  
                      
 
				                      		
 
				  
                       Feature Configuration 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 Frame Relay. 
				  
                      
 
				                      		

                      

                       
				  
                       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 Frame Relay.