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Pup: An Internetwork Architecture

IP.com Disclosure Number: IPCOM000128884D
Original Publication Date: 1979-Dec-31
Included in the Prior Art Database: 2005-Sep-20
Document File: 21 page(s) / 73K

Publishing Venue

Software Patent Institute

Related People

David R. Boggs: AUTHOR [+6]

Abstract

Research in network interconnection techniques has been motivated by the desire to permit communication among diverse, geographically distributed computing resources and users interconnected by a wide variety of network technologies.

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This is the abbreviated version, containing approximately 5% of the total text.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

Pup: An Internetwork Architecture

by David R. Boggs, John F. Shoch, Edward A. Taft, and Robert M. Metcalfel

CSL-79-10 July 1979

Abstract: Pup is the name of an internet packet format (PARC Universal Packet), a hierarchy of protocols, and a style of internetwork communication. The fundamental abstraction is an end-to- end media- independent internetwork datagram. Higher levels of functionality are achieved by end-to-end protocols that are strictly a matter of agreement among the communicating end processes.

This report explores important design issues, sets forth principles that have guided the Pup design, discusses the present implementation in moderate detail, and summarizes experience with an operational internetwork. This work serves as the basis for a functioning internetwork system that provides service to about 1000 computers, on 25 networks of 5 different types, using 20 internetwork gateways.

Key words and phrases: computer networks, protocols, packet switching, internets, network interconnection, gateways, datagrams, virtual circuits, fragmentation

1Present affiliation: Computer Systems Laboratory, Stanford University, Stanford, California 94305.

XEROX PALO ALTO RESEARCH CENTER

3333 Coyote Hill Road / Palo Alto / California 94304

1. Introduction

Research in network interconnection techniques has been motivated by the desire to permit communication among diverse, geographically distributed computing resources and users interconnected by a wide variety of network technologies.

It is the purpose of an internetwork. architecture to provide a uniform framework for communication within a heterogeneous computing, communication, and applications environment. 'Me work described in this paper represents one internetwork architecture, known as Pup, in widespread regular use within Xerox. The name referred originally to the abstract design of a standard internetwork datagram (the PARC Universal Packet), but has expanded in usage to include the whole hierarchy of internetwork protocols as well as a general style for internetwork. communication. To assist in understanding the design of the Pup protocols, it is useful to characterize briefly the environment in which this architecture has evolved. 'Me computational environment includes a large number of "Alto" minicomputers [Kay, 1977; Thacker el aL, 19791 and other personal computers capable of high-quality interaction with human users. Supporting these are various specialized server systems that are shared among many users and provide access to expensive peripherals such as large disks, magnetic tapes, and high-quality printers. Additionally, there are several general-purpose time sharing systems providing customary services for terminal users. The communications environment includes

Xerpx Palo Alto Research Center Page 1 Dec 31, 1979

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Pup: An Internetwork Architecture

several different individual network desi...