FR Configuration Catalogue 

Hardware Configuration of FR

Task for FR Configuration

Activating FR Encapsulation at the Interface 

Configuring Dynamic or Static Address Mapping 

Configuring LMI (Local Management Interface)

Customizing FR Configuration

Configuring FR Subinterface 

Mornitoring and Maintaining FR Linkage 

Demonstration of FR Configuration

This chapter tells how to configure FR on router. The commands for configuring FR can be referred to the relevant chapter concerning “FR Commands” specified in the book entiled “The Reference for Commands of Wide Area Network (WAN) . 

Hardware Configuration of FR

The FR network can be set up based on the following hardware environment:

l         Rounter or Server is directly connected with FR exchange network ;

l         Rounter or Server is connected FR exchange network through the connection with CSU/DSU.

A router can be connected with FR exchange network or through CSU/DSU. However, for the single router port, it has only one choice for the configuration. .

CSU/DSU can convert the sigal of V.35 or RS-499 into E1/T1 carrier signal. Chart 1 illustrates the connections under different connection types.

Chart 1 Typical FR Configuration

FR Port is connected by router and the exchanger provided by the service providers. The single physical connection makes up the whole connection between network equipments.

Task for FR Configuration

In order to use the FR service of network, in addtion to the customed configuration made to meet the requirements of network and monitoring the FR connection on the network all the time, the following steps shall be executed. The configuration is listed in the following.

The Necessary Configuration:  

The following is optional configuration. But these configurations can be changed so as to meet the practical needs.

The specific FR configuration can be referred to the section of “Demonstration of FR Configuration”. The commands for FR can be referred to the relevant chapter concerning “FR Commands” specified in the book entitled “The Reference for Commands of Wide Area Network (WAN).”

Activating FR Encapsulation at the Interface 

The following commands are used to activate FR encapsulation under port configuration mode:

Steps

Commands

Fuction

1 .

interface type number

Setting the port and entering port configuration model

2 .

[no] encapsulation frame-relay 

Activating FR and setting the mode of FR encapsulation

Deleting interface and subinterface encapsulation and the configuaration of FR Protocol by using command “noncommand”.

Remarks: The router of Cisco (R) has two modes of encapsulation, namely, default Cisco(R)mode and IETFRFC 1490mode. The router of the Company can automatically identify these two modes and can adapt these two types of encapsulation dynamically.

Configuring Dynamic or Static Address Mapping

Dynamic address mapping uses Inverse ARP to obtain next protocol address through DLCI. The Inverse ARP inquiry can be realized by consulting the mapping table through the address of router or the server. The mapping table lists the next protocol addresses or the DLCI of output flow.

Under default state, the Inverse ARP is opened. If the other terminal of network supports the Inverse ARP, the Inverse ARP can be activated directly. For the details, please refer to the relevant part of “Prevent or Re-activating Inverse ARP” in this Chapter.

Configuring Dynamic Address Mapping

Under default state, the Inverse ARP is opened on the protocols of the whole activated network  interface. However, if physical interface is not activated, data package cannot be transmitted, thus the Inverse ARP will not work.

When the Inverse ARP is activated under default state, no special commands are needed for configuring the Inverse ARP.

  

Configuring Static Address Mapping

Static Address mapping designates directly the next protocoal address. The static mapping forbids the Inverse ARP, that is, when the static mapping is configured on a DLCI, the Inverse ARP on the DLCI is prohibited automatically.

If the other terminal of netwrotk does not support the Inverse ARP, the static mapping has to be configured.

Under the interface configuration model, the following mapcommand is used to configure static mapping:

 

Command

Function

[no] frame-relay map ip-address pvc dlci [broadcast]

[Deleting or setting] the mapping between the next address and DLCI.

If the key words of broadcast are added, the DLCI will be able to transmit the btoadcast message, which will significantly simplify the network configuration.

For the details of configuring static mapping, please refer to the “Demonstration  of Static Address Mapping” in this Chapter.

Configuring LMI (Local Management Interface)

Direct Configuration of LMI Parameters

FR software supports LMI method developed on the industrial standard. The configuration of LMI needs to take following steps, of which first step is necessary.

 

Configuring The Types of LMI

If router or access server is connected with PDN (Public Data Network), the type of LMI shall match with the type of network. Or, the type of LMI shall consist with the type of special network.

The following three types of LMI can be configured, they are ANSI T1.617 Annex D Group of Four Rev. #1 ITU-T Q.933 Annex A. Router supports the automatic negotiation of FRLMI type. Under the Interface Configuration Model, the following commands are taken to make configuration:

 

Steps

Command

Function

1

[no] frame-relay lmi-type {ansi | bcisco | q933a}

 Configuring the type of LMI, restoring the default configuration of the type of LMI by using command “no”

2

Quit

 Quiting the mode of configuration

3

Write

Writing configuration

 After FR is encapsulated, the default type of LMI is Autosense. This Type is the LMI of 3000 series before.

For the demonstration of configuring the types of LMI, please refer to the part of “Demonstration of Pure FRDCE Configuration”. 

Configuring LMI Polling and the Size of Timer

The equipment of DTE and DCE, various counters, time interval and threshold of LMI can be configured through following commands so as to improve their application performance:

 

Command

Function

frame-relay t391 seconds 

Configuring the link integrity, verifying polling timer

frame-relay t392 seconds

Configuring Polling, verifying timer 

frame-relay n391 number

Configuring pollng counter under complete state  

frame-relay n392 number

Configuring wrong threshold counter

frame-relay n393 number

Configuring mornitoring event counter

The commands used for configuring polling and timer can be referred to the relevant part concerning the FR commands in this Chapter.

Customizing FR Configuration

Configuring FR Exchange

FR exchange is realized based on the DLCI that is viewed as MAC address of LAN (Local Area Network). Through configuring FR SWITCH, router or access server will be able to play a role similar to FR network. A FR network is made up of two parts: DTE equipments of FR (such as router or access server) and FRDCE exchanger. Chart 2 illustrates the relationship between them.

Chart 2 FR Switch Network

In chart 2, Rout A, B and C serve as DTE of FR network, they are linked to each other through FR network. FR exchange allows the configuration equipment similar to FR switching network.

FR exchange can be configured through following steps:

 

Configuring FR Exchange supportive of DEC or NNI

Under global confuguraion model, the following command is used to configure FR exchanger supportive of the port of DTE, DCE or NNI (the default port is DTE port)

 

Command

Function

frame-relay intf-type [dce | dte | nni]

Configuring interface type supported by FR exchange

How to configure DTE equipments or DEC exchange can be referred to the demonstration in the part of “Demonstration of the exchange between Mixed DTE/DCE and PVC in this Chapter.

How to configure NNI can be referred to the part of “Demonstration of FR Exchange Configuration only Supporting DCE Interface”.

Configuring Static Rounter

Under global confuguraion model, the following command is used to configure the rounter of PVC  exchange. :

 Command

Function

[no] frswitch in-port in-dlci out-port out-dlci

 [Deleting or configuring] static rounter of PVC

 How to configure static rounter can be referred to the part of “Demonstration of FR Exchange Configuraton” .

Prohibiting or Reactivating the Inverse ARP of FR

The Inverse ARP of FR is used for seaching protocol address of DLCI on FR network.

The Inverse ARP creats address mapping dynamically while command “map”creats static address mapping. For the details, please refer to the relevant part of “Configuring Dyanmic or Static Mapping” in this Chapter.

Under the default state, the Inverse ARP is opened. Under the following condtion, the Inverse ARP can be prohibited or reactivated:

l         If the protocol of other terminal of network does not support the Inverse ARP, the given protocol and DLCI will prohit the Inverse ARP;

l         If the other terminial of network resupport the Inverse ARP through changing equipment, the given protocol and DLCI wll reactivate the Inverse ARP.

Under interface configuration model, the following commands are used to prohibit or activating Inverse ARP:

Command

Function

frame-relay inverse-arp

Activating Inverse ARP of FR

Configuring FR Subinterface

In order to link and define FR subinterface, it is recommended to refer to the part of “Linking Subinterface”. For defining FR subinterface, the following configuration is used. 

l        Defining FR Subinterface

l        Designating the Address of Subinterface

The demonstration of defining FR subinterface can be referred to the later part of “Demonstration of Configuring Subinterface” in this Chapter.

Knowledge of FR Subinterface

FR Subinterface offers and supports multiple logic interfaces or internetworking on a physical interface, i.e., multiple logic interfaces are linked to a physical interface. When these logic interfaces are in operation, they share the physical configuration parameter of physical interface. But they have their own respective configuration parameters for link layer and network layer.

FR subinterface provides the mechanism for establishing partially-meshed FR network.. Many protocols assumes that logic network bears the transitivity, namely, If Station A can communicate with Station B and Station B can communicate with Station C, Station A will be able to communicate with Station C directly. The transitivity is effective on the LAN (Local Area Network). However, logic network bears no transitivity on FR network. Station A can not communicate with Station C directly unless Station A is directly linked to Station C.

FR subinterface configuration enables a network port to serve as multiple virtual interfaces, which can be used to settle the issue of horizontal division The data package recieced at a virtual interface can be retransmitted through another virtual interface, enven these two interfaces are at the same network  interface. .

The subinterface also offers a means to divide the fully-meshed network into multiple small and complete netshaped subnetwork (or point to point network). Each subnetwork allocates the network number of bit and protocol, jusr as they provide the independent interface connection.

At the port of WAN with encapsulated FR, the subinterface can be configured as follows:

l         Configure DLCI or FR address mapping different from the original port of WAN (it is also called the primary  interface )

l         Configure IP address different with the port of WAN in address sector

Defining FR Subinterface

Under the global configuration model, the following commands are used to configure the subinterface of FR network: 

Steps

Command

Function

1

interface type number

Designating Interface  .

2

encapsulation frame-relay

Setting FR encapsulation on serial-port

3

interface type number.subinterface-number {multipoint | point-to-point}

Designating subinterface

Subinterface can set up point-to-point or multiple points communication (no default value)

Designating the Address of Subinterface

When the primary interface of FR works under DEC mode, the subinterface can be configured by setting the command frame-relay local-dlci to configure a DLCI value exclusive to the subinterface. The value can be analyzed at the destinational terminal through dynamic resolution of Inverse ARP or static address mapping by using command “map”.

Configuring DLCI

The following command is used to configure DLCI value of subinterface:

Command

Functions

[no] frame-relay local-dlci dlci [cir speed]

[Deleting/Designating] DLCI of subinterface.

Remark: This command can be used both for subinterface and primary interface. For point to point subinterface, only one DLCI can be configured.

Configuring the Establishment of Dynamic Address Mapping at Subinterface by Using Inverse ARP

The next protocol address can be obtained through DLCI by using the dynamic address mapping of Inverse ARP. The result of Inverse ARP will be stored in the address-mapping table of router or access server and DLCI. The table will be used to list the second protocol addresses recognized by DLCI.

As network interface is divided into multple interfaces, a method has to be used to differentiate a subinterface and physical interface. The Inverse ARP must be configured and activated under the primary interface. Only by doing so, the subinterface can use the Inverse ARP to set up dynamic address mapping.

By using the flowing command, DLCI of subinterface can be associated.

Command

Function

frame-relay local-dlci dlci [cir speed]

Designating DLCI of multiple point subinterfaces

Configuring Static Address Mapping for Subinterface

Static address mapping designates the next protocol address of DLCI

Under interface configuration model, the following command is used to configure the static address mapping:

Command

Function

[no] frame-relay map ipaddress pvc dlci [broadcast]

[Deleting/setting up] the mapping between next IP protocol address and DLCI.

Remark: For the point to point subinterface, only one static address mapping can be configured.

Mornitoring and Maintaining FR Linkage

Under configuraton model, the following command is used to monitor FR linkage. The detail can be referred to the commands of FR Configuration.

Command

Function

show interface type number

Showing DLCI of FR and LMI type

show frame-relay

Showing current FR Mapping.

show frswitch

Showing information of FR exchange

 

Demonstration of FR Configuration

Here is the demonstration of FR configuration. it includes the following parts:

l        Demonstration of Configuring Encapsulation

l        Demonstration of configuring static address mapping

l      Demonstration of Configuring FR Exchange

l        Demonstration of Subinterface Configuration

Demonstration of Configuring Encapsulation

The following first example is the demonstration of configuring FR protocol at the interface

encapsulation frame-relay

frame-relay map 131.108.123.2 pvc 48 

frame-relay map 131.108.123.3 pvc 49 broadcast

Demonstration of configuring static address mapping

The following demonstration tells how to configure static address mapping.
router1

interface s1/0

ip address 131.108.64.2 255.255.255.0

encapsulation frame-relay

frame-relay intf-type dce

frame-relay local_dlci 43

frame-relay map 131.108.64.1 pvc 43

router2

interface s1/0

ip address 131.108.64.1 255.255.255.0

encapsulation frame-relay

frame-relay map 131.108.64.2 pvc 43

Demonstration of Configuring FR Exchange

The following demonstrations offer the cases of configuring one or multiple routers into the exchanger of FR:

l     Demostration of Configuring PVC Exchange

--In the demonstration, a router has two interfaces, their configuration is DCF. Based on DLCI, Router retransmits the data package received at an interface to another output interface. 

l       Demostration of Pure FR DCE Exchange Configuration 

--In the demonstration, tow rounters are configured into FR exchanger. The standard NNI signaling is used between the two routers.

l        Demonstration of PVC Exchange Configuration of Mixed DTE/DCE

--In the demonstration, a rounter is configured with DCE interface and DTE interface (mixed DTE/DCEFR exchange). It can realize the data package exchange between two DCE ports and between DTE and DCE.

Demonstration of PVC Exchange Configuration

A router can be configured into a special DCEFR exchanger. The exchange is based on DLCI. The router can examine the input DLCI and determine the output interface and DLCI. As the output DLCI replaces the input DLCI, the data package is retransmitted from output interface, thus accomplishing network data exchange.

In Chart 3, router realizes PVC exchange between port 1 and port 2.  DLCI 100 Frame received at port 1 is retransmitted from DLCI 200 at serial-port 2.

Chart 3 PVC Exchnage Configuration

Configuration of Rounter A

!

interface s1/1

encapsulation frame-relay

frame-relay lmi-type ansi

frame-relay intf-type dce

frame-relay local-dlci 100

!

interface s1/2

encapsulation frame-relay

frame-relay intf-type dce

frame-relay local-dlci 200

frswitch s1/1 100 s1/2 200

Demostration of Pure FR DCE Exchange Configuration

Based on the feature of PVC exchange and through router, a complete FR exchange network can be created. In chart 4, rounter A and router B that are used as FR exchanger form a network with two node points. The standard NNI signaling is communicated between rounter A and router C.

Chart 4 The Configuration of FRDCE

The Configuration of router A

!

interface s1/1

encapsulation frame-relay

framerelay intf-type dce

frame-relay lmi-type ansi

frame-relay local-dlci 100

!

interface s1/2

encapsulation frame-relay

frame-relay intf-type nni

frame-relay lmi-type q933a

frame-relay local-dlci 200

frswitch s1/1 100 s1/2 200

The Configuration of router C

!

interface s1/1

encapsulation frame-relay

frame-relay intf-type dce

frame-relay lmi-type ansi

frame-relay local-dlci 300

!

interface s1/2

encapsulation frame-relay

frame-relay intf-type nni

frame-relay lmi-type q933a

frame-relay local-dlci 200

frswitch s1/1 300 s1/2 200

Demonstration of PVC Exchange Configuration of Mixed DTE/DCE

In chart 5, router is configured into FR exchanger of mixed DTE/DCE

Chart 5, PVC Exchnage of Mixed DTE/DCE

 

In the following configuration, router B is used as exchanger of mixed DTE/DCEFR.It can realize the exchange between two DCE ports and between DTE port and DCE port. FR flow can be terminated here. The configurations of three PVC are as follows:  

 

l         From serial-port 1, DLCI 102 to serial-port 2, DLCI 201---DCE exchange

l         From serial-port 1, DLCI 103 to serial-port 3, DLCI 301---DCE/DTE exchange

l         From serial-port 2, DLCI 203 to serial-port 3, DLCI 302---DCE/DTE exchange

 

DLCI 400 is the local termination flow.

The configuration of router B

!

interface s1/1

encapsulation frame-relay

framerelay intf-type dce

frame-relay local-dlci 102

frame-relay local-dlci 103

!

interface s1/2

encapsulation frame-relay

frame-relay intf-type dce

frame-relay local-dlci 201

frame-relay local-dlci 203

!

interface s1/3

ip address 131.108.111.231 255.255.0.0

encapsulation frame-relay

frame-relay lmi-type ansi

frame-relay map 131.108.111.4 pvc 400 broadcast

frswitch s1/1 102 s1/2 201

frswitch s1/1 103 s1/3 301

frswitch s1/2 203 s1/3 302

Demonstration of Subinterface Configuration

The following demonstration tells the basic configuration of subinterface.

The basic Configuration of Subinterface

In the following demonstration, subinterface 1 works under point-to-point model. Subinterface 2 works under multiple points model.  

interface s1/0

encapsulation frame-relay

frame-relay intf-type dce

interface s1/0.1 point-to-point

ip address 10.0.1.1 255.255.255.0

framerelay local-dlci 20

frame-relay map 10.0.1.2 pvc 20

!

interface s1/0.2 multipoint

ip address 10.0.2.1 255.255.255.0

frame-relay local-dlci 20

frame-relay map 10.0.2.2 pvc 20

Configuring FR subinterface by using dynamic address mapping

The following demostration shows the two subinterfaces are configured by using danamic address resolution. Each interface provides its own protocol address and subnetwork. The command “framerelay local-dlci” designates DLCI for subinterface. The address of remote terminal of each subinterface can be obtained through dynamic resolution.

interface s1/0

no ip address

encapsulation frame-relay

frame-relay inverse-arp

frame-relay lmi-type ansi

!

interface s1/0.103 multipoint

ip address 192.168.177.18 255.255.255.0

frame-relay local-dlci 300

!

interface s1/0.104 multipoint

ip address 192.168.178.18 255.255.255.0

frame-relay local-dlci 400