Frame Relay Link Configuration

Introduction

Frame Relay link configuration is the process of defining the protocol parameters for Frame Relay links. Although most Frame Relay protocol parameters can safely be left as default values, some values, such as the LMI type, have to be changed for every installation.

The frd utility builds Frame Relay protocol stacks and configures them. The configuration for each link is stored as ASCII text, which frd converts to binary form before presentation to the communications software. You can use the same configuration file for each link, or a different one for each link, depending on your application.

Configuration Utility

Because data is stored in ASCII form, you can edit the configuration file with a standard text editor such as vi. However, we recommend using tsgconfig. This utility edits the link configuration files named in /etc/packetnets.

When you install Wanware, your answers to the installation script will determine how your Frame Relay system is configured. If you answered everything correctly, then there should not be any problems. This topic provides an overview of what you will need to change if something goes wrong or changes.

Configuration Files

The following configuration files are necessary for Frame Relay to function properly:

/etc/frelhosts
/etc/packetnets
/usr/lib/frel/config/link0

/etc/frelhosts

This file contains the DLCI to host and network mapping for Frame Relay.

You need to have an entry in this file corresponding to each remote host that you wish to exchange TCP/IP data with using Frame Relay. Each entry requires the following fields:

[DLCI]	[hostname]	[networkname]		IP

The DLCI must be a number between 0 and 1018.

The hostname is the name of the remote node.

The networkname is the name of the link that you are using. Usually this is link0 or link1. This will correspond to an entry in /etc/packetnets.

/etc/packetnets

This file will contain an entry telling the Frame Relay drivers what link configuration to use.

/usr/lib/frel/config/linkn

This is the configuration file for your Frame Relay Link. The name of this file will correspond to the name given in the CONFIG field of /etc/packetnets. You can use the tsgconfig utility to edit these files. What you put in this file will be determined by the service that you are paying for from your provider.

frd Protocol Stack Daemon

The frd daemon builds and configures one or more protocol stacks (linked streams modules and drivers), according to instructions outlined in /etc/packetnets. The link configuration files are stored in /usr/lib/frel/config with the name given with the CONFIG tag in /etc/packetnets.

frd will read the /etc/frelhosts file to decide how many /dev/frel devices to allocate for IP encapsulation use. For each entry in this file with the IP flag set, one /dev/frel device will be used. Also, five more are allocated to give some room for dynamic routing entry configuration using the froute utility.

Changing Link Parameters

The frd daemon is started automatically at boot time. It builds the protocol stacks, and sets the link configurations. However, you can also change the configuration without restarting the daemon (and bringing the links down).

To change the Frame Relay configuration, run:

	fconfig -s link0 link.config

where link0 is the network name in /etc/packetnets and link.config is the name of the link configuration file.

Link Configuration Parameter List

The list that follows is sorted alphabetically by parameter name. Each parameter is followed by its default value, followed by an explanation of its effect.

Parameter Default Description

clocking NO Generate clock at as close to the value specified through speed as possible.

enable YES Flag. Controls whether or not Netcom will attempt to build the Stack for this link.

framesize 1600 frame size including the Frame Relay header, but excluding the Frame Check Sequence. Valid values range from 40 to 4092 bytes.

lmitype 1 Represents the type of Link Management Information (LMI) exchanged between your node and the network. It is important to set this value to the LMI type supported on the network to which you are connecting. If the correct LMI data is not passed between your node and the network, the network will not pass data on any virtual circuits.
The following values are valid: 0 - None, 1 - Frame Relay Consortium, 2 - ANSI ANNEX D, 3 - CCITT ANNEX A.

speed 64000 baud rate in bits per second. Enter 56000 for 56 Kbps, 64000 for 64 Kbps, etc. Currently the maximum speed is 2100000. This parameter needs to be set even for externally clocked links.

T391 10 This timer specifies the frequency of Keep Alive Status Enquiry Messages being sent to the network. The value is specified in seconds and ranges from 5 to 30 inclusive.

N391 6 This is the Full Status Polling Counter. Each time this counter is reached the Status Enquiry sent when T391 expires will ask for a Full Status Message instead of the usual Keep Alive message. This counter ranges from 1 to 255 inclusive.

N392 3 This is the Error Threshold Counter. See N393. This counter ranges from 1 to 10 inclusive.

N393 4 This is the Monitored Events Counter. If N392 of N393 events are in error the interface is considered to be inaccessible. An error implies non-reception of a STATUS message in response to a STATUS ENQUIRY message, and has no effect if lmitype is set to 0 (for none). This counter ranges from 1 to 10 inclusive.

Revision 6.3.0 (April 2004)

Parameter	Default	Description
`clocking`	`NO`	Generate clock at as close to the value specified through speed as possible.
`enable`	`YES`	Flag. Controls whether or not Netcom will attempt to build the Stack for this link.
`framesize`	`1600`	frame size including the Frame Relay header, but excluding the Frame Check Sequence. Valid values range from 40 to 4092 bytes.
`lmitype`	`1`	Represents the type of Link Management Information (LMI) exchanged between your node and the network. It is important to set this value to the LMI type supported on the network to which you are connecting. If the correct LMI data is not passed between your node and the network, the network will not pass data on any virtual circuits. The following values are valid: 0 - None, 1 - Frame Relay Consortium, 2 - ANSI ANNEX D, 3 - CCITT ANNEX A.
`speed`	`64000`	baud rate in bits per second. Enter 56000 for 56 Kbps, 64000 for 64 Kbps, etc. Currently the maximum speed is 2100000. This parameter needs to be set even for externally clocked links.
`T391`	`10`	This timer specifies the frequency of Keep Alive Status Enquiry Messages being sent to the network. The value is specified in seconds and ranges from 5 to 30 inclusive.
`N391`	`6`	This is the Full Status Polling Counter. Each time this counter is reached the Status Enquiry sent when T391 expires will ask for a Full Status Message instead of the usual Keep Alive message. This counter ranges from 1 to 255 inclusive.
`N392`	`3`	This is the Error Threshold Counter. See N393. This counter ranges from 1 to 10 inclusive.
`N393`	`4`	This is the Monitored Events Counter. If N392 of N393 events are in error the interface is considered to be inaccessible. An error implies non-reception of a STATUS message in response to a STATUS ENQUIRY message, and has no effect if lmitype is set to 0 (for none). This counter ranges from 1 to 10 inclusive.