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RFC 1926 INFORMATIONAL HUMOR · NETWORKING

IP over ATM (joke): An Experimental Encapsulation of IP Datagrams on Top of ATM

An April 1st joke about sending IP datagrams as Morse-code beeps.

On rfc-editor.org ↗
PUBLISHED
April 1996
AUTHORS
J. Eriksson
STREAM
INDEPENDENT
SUGGESTED NORMAL FREQUENCY
440 Hz
FREQUENCY CHOICES
Seven, from 440 Hz to 784 Hz
DOI
10.17487/RFC1926

RFC text

Contents
Original text · RFC Editor View on rfc-editor.org ↗ 
Network Working Group                                        J. Eriksson
Request for Comments: 1926                                       KTH NOC
Category: Informational                                     1 April 1996


      An Experimental Encapsulation of IP Datagrams on Top of ATM

Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

Abstract

   This RFC describes a method of encapsulating IP datagrams on top of
   Acoustical Transmission Media (ATM).  This is a non-recommended
   standard.  Distribution of this memo is unnecessary.

Overview

   The modern laptop computer of today often contains the hardware
   needed to perform wireless communications by using Acoustical
   Transmission Media, i.e. sound waves.  Until this moment there has
   been no standard on how to run IP on such media.  This document is an
   attempt to fill this silence.

Frame transmission

   The IP datagram is divided into four-bit chunks, in network beep
   order, and converted to characters according to the table below.  A
   single "b" character is prepended as a frame start signal, the
   characters are then transmitted in ordinary morse code by modulating
   a steady tone on and off.  The frequency of this tone is also known
   as the Acoustical Signature (AS number) of the sender.

        Bits    Character       Bits    Character

        0000    "i"             1000    "u"
        0001    "t"             1001    "m"
        0010    "s"             1010    "v"
        0011    "a"             1011    "f"
        0100    "n"             1100    "w"
        0101    "h"             1101    "l"
        0110    "d"             1110    "k"
        0111    "r"             1111    "g"

   To allow more than one Local Acoustical Network (LAN) to coexist the
   use of different AS numbers for different LANs is suggested.  This
   document proposes seven standard AS numbers to be used, see the table
   below for details.

        Name   Frequency

        "a"     440 Hz
        "b"     494 Hz
        "c"     523 Hz
        "d"     587 Hz
        "e"     659 Hz
        "f"     698 Hz
        "g"     784 Hz

   It is assumed that for normal operation AS number "a", 440 Hz will be
   used.

Frame reception

   The above process is simply performed backwards.

Security Considerations

   The author assumes that the users take whatever precautions that are
   necessary before attempting to use this protocol in any crowded area.

Author's Address

   Johnny Eriksson
   KTH NOC
   EMail: bygg@sunet.se

   or

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ISO Plain Language

On this page
PROBLEMThe RFC jokingly says laptops have sound hardware but no standard for sending IP datagrams over sound.
MECHANISMIt encodes each datagram as four-bit chunks, maps them to letters, and sends them in Morse code using a steady tone.
THE JOKEThis April 1st joke document proposes no recommended Internet standard; its title reuses ATM for Acoustical Transmission Media.

§1A Joke About Sound-Based Networking

This April 1st joke RFC proposes encapsulating IP datagrams over what it calls Acoustical Transmission Media (ATM). It says laptops could use sound waves, then presents the idea in a formal technical style.

The memo says it is informational and does not specify an Internet standard. It calls the proposal a non-recommended standard in its abstract.

The RFC is an April 1st joke about sending network data as sound. Its ATM means Acoustical Transmission Media in this proposal.

§2Turning Data into Beeps

The sender divides an IP datagram into four-bit chunks and maps each chunk to a letter using the table in the RFC. It adds a single “b” character as a frame-start signal.

The letters are transmitted in ordinary Morse code by switching a steady tone on and off. The tone frequency acts as the sender's Acoustical Signature.

The sender changes each small piece of data into a letter, then sends the letters as Morse code. The tone's pitch identifies the chosen acoustical network.

§3Frequencies and Reception

The RFC lists seven proposed Acoustical Signature frequencies, named “a” through “g”, from 440 Hz to 784 Hz. It assumes “a”, at 440 Hz, for normal operation and suggests different frequencies for separate Local Acoustical Networks.

Reception reverses the encoding process. The security section advises users to take precautions before trying the protocol in a crowded area.

The proposal assigns different pitches to different local networks. A receiver reverses the steps to recover the data.