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: 2019-Feb-12
Document File: 13 page(s) / 17K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Forster: AUTHOR [+3]

Related Documents

10.17487/RFC1613: DOI

Abstract

This memo documents a method of sending X.25 packets over IP internets by encapsulating the X.25 Packet Level in TCP packets. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 13% 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

Forster, Satz, Glick & Day [Page 1]

RFC 1613 X.25 Over TCP (XOT) May 1994

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 X.25 layer in XOT. Exceptions to this are noted.

2. Conventions

The following language conventions are used in the items of specification in this document:

o MUST, SHALL, or MANDATORY -- This item is an absolute requirement of the specification.

o SHOULD or RECOMMEND -- This item should generally be followed for all but exceptional circumstances.

o MAY or OPTIONAL -- This item is truly optional and may be followed or ignored according to the needs of the implementor.

In some places in this document, there is parenthetical material labeled "DISCUSSION". This material is intended to give clarification and explanation of the preceding text.

3. Relationship Between XOT and X.25

When a networking device (a host, router,...

Processing...
Loading...