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`AX.25 Amateur Packet-Ra
`
`' Link-Layer Protocol
`
`
`
`Version 2.0
`
`October 1984
`
`BY
`
`1
`
`Terry L. Fox, WB4JFl
`ul
`
`I1
`
`
`
`American Radio Relay League, Inc.
`
`Newington, CT USA 06111
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`Page 000007
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`.___g____________________________________________
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`This protocol is intended as a guide to aid in the design and use of
`amateur packet-radio systems, in order to ensure link-layer compatibility
`between stations. The existence of this protocol does not preclude anyone
`from designing, marketing or using products} processes or procedures not
`conforming to the protocol. This protocol is subject to periodic review, and
`users are encouraged to use the latest edition.
`
`TK ‘79 so
`-Fe;
`
`/9??
`
`Copyright (c) 1984 by
`
`The American Radio Relay League, Inc.
`
`Copyright secured under the Pan-American Convention
`
`International Copyright secured
`
`56 of the Radio Amateur’s Library, published by
`This work is publication No.
`the League. Blanket permission to copy this publication by end users for
`noncommercial purposes is hereby granted.
`R0 part of this work may be
`reproduced in any form where such copy is offered in exchange for any payment
`unless written permission has first been secured from the publisher.
`
`Printed in USA
`
`Quedan reservados todos los derechos
`
`Library of Congress Catalog Card Number:
`
`ISBN:
`
`0—87259-011-9
`
`$8.00 in USA
`$9.00 Canada and elsewhere
`
`ii
`
`U- —n
`84-72853
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`N
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`M
`“\
`‘V
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`AX.25 Amateur Packet-Radio Link-Layer Protocol
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`.".'-V‘
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`
`
`4Z%4§32¥réQr/“fg
`
`Foreword
`
`Packet radio is a mode of communications that will link Amateur Radio
`stations together directly or by means of a network.
`It is based on the
`latest technology, provides error-free communications, channel sharing by many
`stations, and automatic routing throughout a global data network.
`
`in a number of areas
`Amateur packet-radio local networks exist
`throughout North America and overseas. As this is written, amateurs are
`cascading packet repeaters up and down the East and West Coasts to extend the
`range of individual stations on VB. Experimental packet-radio contacts are
`taking place on the HF bands, via the AMSAT OSCAR 10 satellite, and using VHF
`meteor-scatter propagation. All
`these stations and networks can talk to one
`another only if common standards are used.
`
`This link-layer protocol document represents the culmination of several
`years of work by amateurs t
`.develop a standard protocol for global use.
`The
`link layer is level
`2 of t e International Organization for Standardization
`(ISO) seven-layered reference model of Open Systems Interconnection (081).
`The other layers needed for amateur packet radio are now under active
`consideration.
`,l
`
`This link-layer protocol is not simply a paper exercise. The written
`definition has existed in its original form since 1982, and has undergone
`evolutionary improvements over these past two years. Operationally proven
`link—layer software versions have kept pace with protocol agreements. The
`result is a mature protocol that has been validated by practical software over
`a two-year period of development.
`
`I would like to acknowledge the special contributions made to this
`protocol by the author, Terry Fox, WB4JFI,
`the amateur packet-radio
`organizations who cooperated in the development and implementation of this
`protocol, and the ARRL Ad Hoc Committee on Digital Communication, created by
`the League's Board of Directors, as a recognized medium for presenting
`standards proposals and resolving differences.
`
`David Sumner, Klzz
`General Manager
`
`iii
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`Page 000009
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