Migrating X.25 over PSI to X.25 over TCP/IP (XOT)

1 Introduction
X.25 is the International Telecommunication Union-Telecommunication Standardization Sector
(ITU-T) Protocol standard for WAN communication. X.25 defines how connections between user
devices and Network devices are established and maintained in a packet- switched data network.
With Ethernet evolving as the preferred network backbone for all environments, X.25 customers
are seeking solutions to run X.25 applications on Ethernet interface.
X.25 over TCP (XOT) is based on RFC 1613 (Cisco Systems X.25 over TCP (XOT)). Configuring
XOT allows X.25 layer 3 to connect to TCP/IP stack instead of LAP-B and provides X.25 functionality
on top of a TCP/IP infrastructure.
This document discusses the migration of X.25 over PSI to XOT using Ethernet cards. It also discusses
the benefits of migrating to XOT.
Table 1 Terms and Definitions
DefinitionTerm
Application Programming InterfaceAPI
International Telegraph and Telephone Consultative CommitteeCCITT
Data Circuit terminating EquipmentDCE
Data Link Provider InterfaceDLPI
Destination Service Access PointDSAP
Data Terminal EquipmentDTE
HP Integrity Virtual MachinesHPVM
International Telecommunication Union-Telecommunication standardization
Sector
ITU
Internet Assigned Numbers AuthorityIANA
Local Area NetworkLAN
Link Access Procedure BalancedLAPB
Logical Link ControlLLC
Logical Link Control type 2LLC2
Open Systems InterconnectionOSI
Packet Layer ProtocolPLP
Programmable Serial InterfacePSI
Packet Switched Public Data NetworkPSPDN
Service Access PointSAP
System Administration ManagerSAM
Source Service Access PointSSAP
Wide Area NetworkWAN
X.25 over LLC2XOL
X.25 over TCPXOT
4 Introduction