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DUAL - A Packet Format for a New
Amateur Radio Link Layer

Omid Mohammadi
Warren Toomey VK1XWT
Lawrie Brown VK1KLB

DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY COLLEGE
THE UNIVERSITY OF NEW SOUTH WALES
AUSTRALIAN DEFENCE FORCE ACADEMY
CANBERRA, ACT
Fri Feb 10 12:58:13 EST 1995

Technical Report CS01/95

Abstract

The standard amateur packet radio protocol, AX.25, provides the end-user with a virtual circuit interface to the link layer, while implementing this using packets, and using a CSMA medium access control mechanism. This paper suggests that the link layer in this application area should be separated into 3 layers (LLC, MAC and Physical Layer), and a set of modular protocols for each part be designed for amateur radio use. A new simplified Logical Link Control layer, DUAL, is described, which is not only more suitable than AX.25 for the transmission of higher-layer traffic, but also more bandwidth-efficient. This is achieved by using link layer addresses tailored to the network protocol used, minimizing the link layer overheads, and by incorporating a modified IP header compression scheme adapted for use in a multi-point environment.



omidm@cs.adfa.edu.au
Fri Feb 10 12:57:56 EST 1995