X.25 Protocols

Document ID: 14213

Document contributed by Johan Claes from Belgacom.

Contents

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
Background Information
Configure
      Network Diagram
      Configurations
Verify
Troubleshoot
      Troubleshooting Commands
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Related Information

Introduction

This document presents a sample configuration of X.25 on the ISDN D channel.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

This document is not restricted to specific software and hardware versions.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

For more information on document conventions, refer to Cisco Technical Tips Conventions.

Background Information

X.25 on the D channel is a feature that was introduced in Cisco IOS® Software release 11.2(4)F. Hence, it is also available in 11.3 and higher IOS main releases. To view the original feature description, see Release Notes for Cisco IOS Release 11.2F.

Currently, the IOS software allows two ways to transport X.25 traffic on the ISDN D channel:

• The first method is the aforementioned X.25 on the D channel feature, available since IOS version 11.2(4)F. The sample configuration shown in this document corresponds to this first method.

• The second method is the X.25 on ISDN using Always On/Direct ISDN (AO/DI) feature, available since IOS version 11.3(3)T.

To configure X.25 traffic over an ISDN D channel, refer to the Configuring X.25 on ISDN and Configuring X.25 on ISDN using Always On/Dynamic ISDN (AO/DI) chapters in the Dial Solutions Configuration Guide.

For a complete description of the commands, refer to the X.25 on ISDN Commands and X.25 on ISDN using Always On/Dynamic ISDN (AO/DI) Commands chapters in the Dial Solutions Command Reference.

Configure

In this section, you are presented with the information to configure the features described in this document.

Note: To find additional information on the commands used in this document, use the Command Lookup Tool ( registered customers only) .

Network Diagram

This document uses this network setup:

The Telephone Company's switch must provide the X.25 on the ISDN D channel service. In the sample configuration shown below, the static terminal endpoint identifier (TEI) configured must also be given by the Telephone Company.

Configurations

This document uses these configurations:

version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname remote
!
enable password cisco
!

ip subnet-zero

isdn switch-type basic-net3
x25 routing
!
interface BRI0
 no ip address
 no ip directed-broadcast
 dialer load-threshold 1 either
 isdn switch-type basic-net3
 isdn x25 static-tei 1
 isdn x25 dchannel
 no fair-queue
!
interface BRI0:0
 ip address 192.168.1.1 255.255.255.252
 no ip directed-broadcast
 no ip mroute-cache
 x25 address 12503372501
 x25 htc 2
 x25 idle 1
 x25 map ip 192.168.1.2 2231146
!
ip classless
!
end

version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
service udp-small-servers
service tcp-small-servers
!
hostname central
!
enable password cisco
!

ip subnet-zero
x25 routing
!
interface Serial0
 bandwidth 9600
 ip address 192.168.1.2 255.255.255.252
 no ip directed-broadcast
 encapsulation x25
 no ip route-cache
 no ip mroute-cache
 x25 address 2231146
 x25 map ip 192.168.1.1 12503372501 no-outgoing
 lapb T1 1000
!
ip classless
!
end

central#

Verify

This section provides information you can use to confirm your configuration is working properly.

Certain show commands are supported by the Output Interpreter Tool ( registered customers only) , which allows you to view an analysis of show command output.

• show x25 vc—Display information about active switched virtual circuits (SVCs) and permanent virtual circuits (PVCs).

• show x25 map—Display information about configured address maps.

remote#ping 192.168.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.2, timeout is 2 seconds:
!!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 392/412/428 ms 
remote# 

remote#show x25 vc 
SVC 2, State: D1, Interface: BRI0:0      
Started 00:01:08, last input 00:00:32, output 00:00:32  
Connects 2231146 <-> ip 192.168.1.2 
Call PID cisco, Data PID none 
Window size input: 2,      output: 2 
Packet size input: 128, output: 128 
PS: 3? PR: 3? ACK: 2 Remote  PR: 3? RCNT: 1 RNR: no 
P/D state timeouts: 0 timer (secs): 27 
data bytes 1900/1900 packets 19/19 Resets 0/0 RNRs 0/0 REJs 0/0 INTs 0/0 
remote# 

remote#show  x25 map 
BRI0:0: X.121 2231146 <-> ip 192.168.1.2  
permanent, 0 VC:

Troubleshoot

Troubleshooting Commands

Note: Before issuing debug commands, refer to Important Information on Debug Commands.

• debug x25—Display information about all X.25 traffic or a specific X.25 service class.

Output from the debug x25 command is shown here:

remote# 
00:13:44: BRI0:0-D: X.25 O R1 Call (18) 8 lci 2 
00:13:44:  From (11): 12503372501 To (7): 2231146 
00:13:44:  Facilities: (0) 
00:13:44:  Call User Data (4): 0xCC000000 (ip) 
00:13:44: BRI0:0-D: X.25 I R1 Call Confirm (14) 8 lci 2 
00:13:44:  From (11): 12503372501 To (7): 2231146 
00:13:44:  Facilities: (0) 
remote#

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Related Information

• X.25 and LAPB Commands
• Technical Support - Cisco Systems