Browse Prior Art Database

cisco Systems X.25 over TCP (XOT) (RFC1613)

IP.com Disclosure Number: IPCOM000002449D
Original Publication Date: 1994-May-01
Included in the Prior Art Database: 2000-Sep-12
Document File: 11 page(s) / 27K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Forster: AUTHOR [+4]

Abstract

It is sometimes desirable to transport X.25 over IP internets. The X.25 Packet Level requires a reliable link level below it and normally uses LAPB. This memo documents a method of sending X.25 packets over IP internets by encapsulating the X.25 Packet Level in TCP packets.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 10% of the total text.

Network Working Group J. Forster

Request for Comments: 1613 G. Satz

Category: Informational G. Glick

cisco Systems, Inc.

R. Day

JANET

May 1994

cisco Systems X.25 over TCP (XOT)

Status of this Memo

This memo provides information for the Internet community. This memo

does not specify an Internet standard of any kind. Distribution of

this memo is unlimited.

Table of Contents

1. Introduction....................................................1

2. Conventions.....................................................2

3. Relationship Between XOT and X.25...............................2

4. Overall Packet Format...........................................3

4.1 XOT Header....................................................4

5. TCP Connection, Port Number, and Logical Channel Numbers (LCNs).4

6. XOT Packets.....................................................5

6.1 Virtual Circuit Setup and Clearing............................5

6.2 Data and Flow Control.........................................6

6.3 Interrupt, and Reset Packets..................................8

6.4 Restart, DTE Reject, Diagnostics, and Registration............8

6.5 PVC Setup.....................................................8

7. Acknowledgments................................................12

8. Security Considerations........................................12

9. References.....................................................12

10. Authors' Addresses.............................................13

1. Introduction

It is sometimes desirable to transport X.25 over IP internets. The

X.25 Packet Level requires a reliable link level below it and

normally uses LAPB. This memo documents a method of sending X.25

packets over IP internets by encapsulating the X.25 Packet Level in

TCP packets.

TCP provides a reliable byte stream. X.25 requires that the layer

below it provide message semantics, in particular the boundary

between packets. To provide this, a small (4-byte) XOT header is

used between TCP and X.25. The primary content of this header is a

length field, which is used to separate the X.25 packets within the

TCP stream.

In general, the normal X.25 protocol packet formats and state

transition rules apply to the...