RFC 916 (rfc916) - Page 1 of 54

Reliable Asynchronous Transfer Protocol (RATP)

Network Working Group                                            G. Finn
Request for Comments: 916                                            ISI
                                                            October 1984

             RELIABLE ASYNCHRONOUS TRANSFER PROTOCOL (RATP)


Status of This Memo

   This RFC suggests a proposed protocol for the ARPA-Internet
   community, and requests discussion and suggestions for improvements.
   Distribution of this memo is unlimited.

   This paper proposes and specifies a protocol which allows two
   programs to reliably communicate over a communication link.  It
   ensures that the data entering one end of the link if received
   arrives at the other end intact and unaltered.  The protocol, named
   RATP, is designed to operate over a full duplex point-to-point
   connection.  It contains some features which tailor it to the RS-232
   links now in common use.

Introduction

   We are witnessing today an explosive growth in the small or personal
   computer market.  Such inexpensive computers are not normally
   connected to a computer network.  They are most likely stand-alone
   devices.  But virtually all of them have an RS-232 interface.  They
   also usually have a modem.  This allows them to communicate over the
   telephone with any other similarly equipped computer.

   The telephone system is a pervasive network, but one of the
   characteristics of the telephone system is the unpredictable quality
   of the circuit.  The standard telephone circuit is designed for voice
   communication and not data communication.  Voice communication
   tolerates a much higher degree of 'noise' than does a data circuit,
   so a voice circuit is tolerant of a much higher level of noise than
   is a data circuit.  Thus it is not uncommon for a byte of data
   transferred over a telephone circuit to have noise inserted.  For the
   same reason it is also not uncommon to have spurious data bytes added
   to the data stream.

   The need for a method of reliably transferring data over an RS-232
   point-to-point link has become severe.  As the number of powerful
   personal computers grows, the need for them to communicate with one
   another grows as well.  The new markets and new services that these
   computers will eventually allow their users to access will rely
   heavily upon the telephone system.  Services like electronic mail,
   electronic banking, ordering merchandise from home with a personal
   computer, etc.  As the information revolution proceeds data itself
   will become a commodity.  All require accuracy of the data sent or
   received.


Finn