RFC 1149 EXPERIMENTAL APRIL FOOLS · LINK LAYER

IP over Avian Carriers: A Standard for the Transmission of IP Datagrams on Avian Carriers

IP datagrams on a paper scroll wrapped around a bird's leg.

On rfc-editor.org ↗
PUBLISHED
April 1990
AUTHORS
D. Waitzman
ORG
BBN STC
STREAM
INDEPENDENT
UPDATED BY
RFC 2549 — Avian Carriers QoS, RFC 6214 — IPv6 over avian carriers
TYPICAL MTU
256 milligrams
FRAME
Hex on a paper scroll, duct tape
EXTENDED BY
RFC 2549
DOI
10.17487/RFC1149

RFC text

Contents
Original text · RFC Editor View on rfc-editor.org ↗
Network Working Group                                        D. Waitzman
Request for Comments: 1149                                       BBN STC
                                                            1 April 1990


   A Standard for the Transmission of IP Datagrams on Avian Carriers

Status of this Memo

   This memo describes an experimental method for the encapsulation of
   IP datagrams in avian carriers.  This specification is primarily
   useful in Metropolitan Area Networks.  This is an experimental, not
   recommended standard.  Distribution of this memo is unlimited.

Overview and Rational

   Avian carriers can provide high delay, low throughput, and low
   altitude service.  The connection topology is limited to a single
   point-to-point path for each carrier, used with standard carriers,
   but many carriers can be used without significant interference with
   each other, outside of early spring.  This is because of the 3D ether
   space available to the carriers, in contrast to the 1D ether used by
   IEEE802.3.  The carriers have an intrinsic collision avoidance
   system, which increases availability.  Unlike some network
   technologies, such as packet radio, communication is not limited to
   line-of-sight distance.  Connection oriented service is available in
   some cities, usually based upon a central hub topology.

Frame Format

   The IP datagram is printed, on a small scroll of paper, in
   hexadecimal, with each octet separated by whitestuff and blackstuff.
   The scroll of paper is wrapped around one leg of the avian carrier.
   A band of duct tape is used to secure the datagram's edges.  The
   bandwidth is limited to the leg length.  The MTU is variable, and
   paradoxically, generally increases with increased carrier age.  A
   typical MTU is 256 milligrams.  Some datagram padding may be needed.

   Upon receipt, the duct tape is removed and the paper copy of the
   datagram is optically scanned into a electronically transmittable
   form.

Discussion

   Multiple types of service can be provided with a prioritized pecking
   order.  An additional property is built-in worm detection and
   eradication.  Because IP only guarantees best effort delivery, loss
   of a carrier can be tolerated.  With time, the carriers are self-
   regenerating.  While broadcasting is not specified, storms can cause
   data loss.  There is persistent delivery retry, until the carrier
   drops.  Audit trails are automatically generated, and can often be
   found on logs and cable trays.

Security Considerations

   Security is not generally a problem in normal operation, but special
   measures must be taken (such as data encryption) when avian carriers
   are used in a tactical environment.

Author's Address

   David Waitzman
   BBN Systems and Technologies Corporation
   BBN Labs Division
   10 Moulton Street
   Cambridge, MA 02238

   Phone: (617) 873-4323

   EMail: dwaitzman@BBN.COM

AI ELI5

On this page
PROBLEMMove IP datagrams between two places that have no electronic link between them.
MECHANISMPrint the datagram in hexadecimal on a small paper scroll, wrap it around one leg of an avian carrier and secure it with duct tape. The receiver removes the tape and optically scans the paper back into electronic form.
WHAT CAME OF ITIt is a joke with a real number: published on 1 April 1990 as an Experimental RFC, it was extended by RFC 2549 and was actually tried by the Bergen Linux User Group in 2001.

§1Introduction

Published on April 1st, 1990, RFC 1149 is one of the most beloved documents in Internet history. It specifies a method for transmitting IP datagrams using homing pigeons as the physical carrier medium.

While written as humor, RFC 1149 is a legitimate document in the RFC series. It was even implemented and tested on April 28, 2001, by the Bergen Linux User Group in Norway, achieving a 55% packet loss rate and round-trip times of thousands of seconds.

This is a joke document that is also a real document. It says how you could send internet messages by bird, and a group of people once did.

§2Overview

Avian carriers can provide high delay, low throughput, and low altitude service. The connection topology is limited to a single point-to-point path for each carrier, used with standard carriers, but many carriers can be used without significant interference with each other, outside of early spring.

Bandwidth
Depends on the weight capacity of the carrier and the storage medium. A pigeon carrying a microSD card could theoretically transfer terabytes per trip.
Latency
Homing pigeon speed averages 50 mph (80 km/h), giving a latency measured in hours for typical distances.
Packet Loss
Susceptible to hawks, cats, weather, and other environmental factors. The Bergen test recorded 55% packet loss.

Birds are slow and carry very little, but there are lots of sky to go around, so many birds can fly at once without bumping into each other.

§3Frame Format

The IP datagram is printed on a small scroll of paper, in hexadecimal, with each octet separated by "whitestuff and blackstuff". The scroll of paper is wrapped around one leg of the avian carrier.

Frame Format
The IP datagram is printed, on a small scroll
of paper, in hexadecimal, with each octet
separated by whitestuff and blackstuff.

The scroll of paper is wrapped around one
leg of the avian carrier.

A band of duct tape is used to secure
the datagram's edges.

You write the message in numbers on a little paper scroll, wrap it around the bird's leg and tape it on. At the other end someone takes the tape off and scans the paper into a computer.

one datagram, source to destination
Source hostAvian carrierDestination host
  1. Scroll with the hex datagram wrapped on one legThe datagram is printed in hexadecimal, octets separated by whitestuff and blackstuff. A band of duct tape secures the edges.
  2. Flight to the destinationHigh delay, low throughput and low altitude service. Loss of a carrier can be tolerated because IP is best effort.
  3. Tape removed, paper optically scannedThe paper copy is scanned into an electronically transmittable form.

§4Implementation

The specification addresses several practical implementation concerns for deploying IP over avian carrier networks.

MTUVariable; typically 256 milligrams, and generally increasing with carrier age
BandwidthLimited to the leg length
PaddingSome datagram padding may be needed
StormsBroadcasting is not specified; storms can cause data loss

Audit trails are automatically generated, and can often be found on logs and cable trays.

A bird can only carry so much, so the message has to be small, and a storm can make the bird lose it.

§5Quality of Service

RFC 1149 itself says little about quality of service (RFC 2549 adds it), but a rough, informal comparison with Ethernet shows how different avian carriers are.

Metric
Avian Carriers
Ethernet
Latency
Hours to days
Microseconds
Bandwidth
High (if using microSD)
1-100 Gbps
Packet Loss
~55% (tested)
< 0.01%
Jitter
Very high (wind-dependent)
Very low

Compared with a normal network cable, a bird is very slow and often loses the message, but it can carry a lot at once if you give it a big memory card.

§6References