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Compressing IPX Headers Over WAN Media (CIPX) (RFC1553) Disclosure Number: IPCOM000002386D
Original Publication Date: 1993-Dec-01
Included in the Prior Art Database: 2019-Feb-13
Document File: 23 page(s) / 27K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

S. Mathur: AUTHOR [+1]

Related Documents

10.17487/RFC1553: DOI


This document describes a method for compressing the headers of IPX datagrams (CIPX). [STANDARDS-TRACK]

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 8% of the total text.

Network Working Group S. Mathur Request for Comments: 1553 M. Lewis Category: Standards Track Telebit Corporation December 1993

Compressing IPX Headers Over WAN Media (CIPX)

Status of this Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.


This document describes a method for compressing the headers of IPX datagrams (CIPX). With this method, it is possible to significantly improve performance over lower speed wide area network (WAN) media. For normal IPX packet traffic, CIPX can provide a compression ratio of approximately 2:1 including both IPX header and data. This method can be used on various type of WAN media, including those supporting PPP and X.25.

This memo ia a product of the Point-to-Point Protocol Extensions (PPPEXT) Working Group of the IETF. Comments should be sent to the authors and the mailing list.

Specification of Requirements

In this document, several words are used to signify the requirements of the specification. These words are often capitalized.


This word, or the adjective "required", means that the definition is an absolute requirement of the specification.


This phrase means that the definition is an absolute prohibition of the specification.

Mathur & Lewis [Page 1]

RFC 1553 CIPX December 1993


This word, or the adjective "recommended", means that there may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood and carefully weighed before choosing a different course.


This word, or the adjective "optional", means that this item is one of an allowed set of alternatives. An implementation which does not include this option MUST be prepared to interoperate with another implementation which does include the option.


Internetwork Packet Exchange (IPX) is a protocol defined by the Novell Corporation [1]. It is derived from the Internet Datagram Protocol (IDP) protocol of the Xerox Network Systems (XNS) family of protocols. IPX is a datagram, connectionless protocol that does not require an acknowledgment for each packet sent. The IPX protocol corresponds to the network layer of the ISO model.

Usually, there is a transport layer protocol above IPX. The most common transport protocol is the Netware Core Protocol (NCP), which is used for file server access. The Sequenced Packet Exchange (SPX) is the reliable connection-based transport protocol commonly used by applications.

The IPX packet consists of a 30 octet IPX header, usually followed by the transport layer protocol header. The NCP header is 6 octets in length. The SPX header is 12 octets in length.

Two strategies are described below for compressing IPX headers. Th...