This is a purely informative rendering of an RFC that includes verified errata. This rendering may not be used as a reference.
The following 'Verified' errata have been incorporated in this document:
EID 8054
Network Working Group J. Postel
Request for Comments: 2223 J. Reynolds
Obsoletes: 1543, 1111, 825 ISI
Category: Informational October 1997
Instructions to RFC Authors
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.
Copyright Notice
Copyright (C) The Internet Society (1997). All Rights Reserved.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Editorial Policy . . . . . . . . . . . . . . . . . . . . . . 3
3. Format Rules . . . . . . . . . . . . . . . . . . . . . . . . 4
3a. ASCII Format Rules . . . . . . . . . . . . . . . . . . . . 5
3b. PostScript Format Rules . . . . . . . . . . . . . . . . . . 6
4. Header . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4a. First Page Heading . . . . . . . . . . . . . . . . . . . . 7
4b. Running Header . . . . . . . . . . . . . . . . . . . . . . 8
4c. Running Footer . . . . . . . . . . . . . . . . . . . . . . 8
5. Status Section . . . . . . . . . . . . . . . . . . . . . . . 8
6. Copyright Notice . . . . . . . . . . . . . . . . . . . . . . 9
7. Introduction Section . . . . . . . . . . . . . . . . . . . . 9
8. References Section . . . . . . . . . . . . . . . . . . . . 11
9. Security Considerations Section . . . . . . . . . . . . . 11
10. Author's Address Section . . . . . . . . . . . . . . . . . 11
11. Copyright Section . . . . . . . . . . . . . . . . . . . . 11
12. Relation to other RFCs . . . . . . . . . . . . . . . . . . 12
13. Protocol Standards Process . . . . . . . . . . . . . . . . 13
14. Contact . . . . . . . . . . . . . . . . . . . . . . . . . 13
15. Distribution Lists . . . . . . . . . . . . . . . . . . . . 14
16. RFC Index . . . . . . . . . . . . . . . . . . . . . . . . 14
17. Security Considerations . . . . . . . . . . . . . . . . . 14
18. References . . . . . . . . . . . . . . . . . . . . . . . . 14
19. Authors' Addresses . . . . . . . . . . . . . . . . . . . . 15
20. Appendix - RFC "nroff macros" . . . . . . . . . . . . . . 16
21. Full Copyright Statement . . . . . . . . . . . . . . . . . 20
1. Introduction
This Request for Comments (RFC) provides information about the
preparation of RFCs, and certain policies relating to the publication
of RFCs.
The RFC series of notes covers a broad range of interests. The core
topics are the Internet and the TCP/IP protocol suite. However, any
topic related to computer communication may be acceptable at the
discretion of the RFC Editor.
Memos proposed to be RFCs may be submitted by anyone. One large
source of memos that become RFCs is the Internet Engineering Task
Force (IETF). The IETF working groups (WGs) evolve their working
memos (known as Internet Drafts or I-Ds) until they feel they are
ready for publication, then the memos are reviewed by the Internet
Engineering Steering Group (IESG), and if approved sent by the IESG
to the RFC Editor.
Most of the memos submitted to the RFC Editor from independent
sources will be reviewed by the IESG for possible relationship to
work in progress in the IETF Working Groups.
RFCs are distributed online by being stored as public access files,
and a short message is sent to the distribution list indicating the
availability of the memo.
The online files are copied by the interested people and printed or
displayed at their site on their equipment. This means that the
format of the online files must meet the constraints of a wide
variety of printing and display equipment. (RFCs may also be
returned via e-mail in response to an e-mail query, or RFCs may be
found using information and database searching tools such as Gopher,
Wais, or the World Wide Web (WWW).
RFCs have been traditionally published and continue to be published
in ASCII text.
While the primary RFCs is always an ASCII text file, secondary or
alternative versions of RFC may be provided in PostScript. This
decision is motivated by the desire to include diagrams, drawings,
and such in RFCs. PostScript documents (on paper only, so far) are
visually more appealing and have better readability.
PostScript was chosen for the fancy form of RFC publication over
other possible systems (e.g., impress, interpress, oda) because of
the perceived wide spread availability of PostScript capable
printers.
However, many RFC users read the documents online and use various
text oriented tools (e.g., emacs, grep) to search them. Often, brief
excerpts from RFCs are included in e-mail. These practices are not
yet practical with PostScript files.
PostScript producing systems are less standard than is desirable and
that several of the document production systems that claim to produce
PostScript actually produce nonstandard results.
In the future, it may be necessary to identify a set of document
production systems authorized for use in production of PostScript
RFCs, based on the reasonableness of the output files they generate.
2. Editorial Policy
Documents proposed to be RFCs are reviewed by the RFC Editor and
possibly by other reviewers he selects.
The result of the review may be to suggest to the author some
improvements to the document before publication.
Occasionally, it may be apparent that the topic of a proposed RFC is
also the subject of an IETF Working Group, and that the author could
coordinate with the working group to the advantage of both. The
usual result of this is that a revised memo is produced as a working
group Internet Draft and eventually emerges from the IETF process as
a recommendation from the IESG to the RFC Editor.
In some cases it may be determined that the submitted document is not
appropriate material to be published as an RFC.
In some cases it may be necessary to include in the document a
statement based on the reviews about the ideas in the document. This
may be done in the case that the document suggests relevant but
inappropriate or unsafe ideas, and other situations.
The RFC Editor may make minor changes to the document, especially in
the areas of style and format, but on some occasions also to the
text. Sometimes the RFC Editor will undertake to make more
significant changes, especially when the format rules (see below) are
not followed. However, more often the memo will be returned to the
author for the additional work.
Documents intended to become RFCs specifying standards track
protocols must be approved by the IESG before being sent to the RFC
Editor. The established procedure is that when the IESG completes
work on a document that is to become a standards track RFC the
communication will be from the Secretary of the IESG to the RFC
Editor. Generally, the documents in question are Internet Drafts.
The communication usually cites the exact Internet Draft in question
(by file name). The RFC Editor must assume that only that file is to
be processed to become the RFC. If the authors have small
corrections to the text, they should be sent to the RFC Editor
separately (or as a "diff"), authors should not send a new version of
the document.
In some cases, authors prepare alternate secondary versions of RFCs
in fancy format using PostScript. Since the ASCII text version of
the RFC is the primary version, the PostScript version must match the
text version. The RFC Editor must decide if the PostScript version
is "the same as" the ASCII version before the PostScript version can
be published.
The effect of this is that the RFC Editor first processes the ASCII
version of the memo through to publication as an RFC. If the author
wishes to submit a PostScript version at that point that matches the
ASCII version (and the RFC Editor agrees that it does), then the
PostScript version will be installed in the RFC repositories and
announced to the community.
Due to various time pressures on the RFC Editorial staff, the time
elapsed between submission and publication can vary greatly. It is
always acceptable to query (ping) the RFC Editor about the status of
an RFC during this time (but not more than once a week). The two
weeks preceding an IETF meeting are generally very busy, so RFCs
submitted shortly before an IETF meeting are most likely to be
published after the meeting.
3. Format Rules
To meet the distribution constraints, the following rules are
established for the two allowed formats for RFCs: ASCII and
PostScript.
The RFC Editor attempts to ensure a consistent RFC style. To do this
the RFC Editor may choose to reformat the RFC submitted. It is much
easier to do this if the submission matches the style of the most
recent RFCs. Please do look at some recent RFCs and prepare yours in
the same style.
You must submit an editable online document to the RFC Editor. The
RFC Editor may require or make minor changes in format or style and
will insert the actual RFC number.
Most of the RFCs are processed by the RFC Editor with the unix
"nroff" program using a very simple set of the formatting commands
(or "requests") from the "ms" macro package (see the Appendix). If a
memo submitted to be an RFC has been prepared by the author using
nroff, it is very helpful to let the RFC Editor know that when it is
submitted.
3a. ASCII Format Rules
The character codes are ASCII.
Each page must be limited to 58 lines followed by a form feed on a
line by itself.
Each line must be limited to 72 characters followed by carriage
return and line feed.
No overstriking (or underlining) is allowed.
These "height" and "width" constraints include any headers,
footers, page numbers, or left side indenting.
Do not fill the text with extra spaces to provide a straight right
margin.
Do not do hyphenation of words at the right margin.
Do not use footnotes. If such notes are necessary, put them at
the end of a section, or at the end of the document.
Use single spaced text within a paragraph, and one blank line
between paragraphs.
Note that the number of pages in a document and the page numbers
on which various sections fall will likely change with
reformatting. Thus cross references in the text by section number
usually are easier to keep consistent than cross references by
page number.
RFCs in ASCII Format may be submitted to the RFC Editor in e-mail
messages (or as online files) in either the finished publication
format or in nroff. If you plan to submit a document in nroff
please consult the RFC Editor first.
3b. PostScript Format Rules
Standard page size is 8 1/2 by 11 inches.
Margin of 1 inch on all sides (top, bottom, left, and right).
Main text should have a point size of no less than 10 points with
a line spacing of 12 points.
Footnotes and graph notations no smaller than 8 points with a line
spacing of 9.6 points.
Three fonts are acceptable: Helvetica, Times Roman, and Courier.
Plus their bold-face and italic versions. These are the three
standard fonts on most PostScript printers.
Prepare diagrams and images based on lowest common denominator
PostScript. Consider common PostScript printer functionality and
memory requirements.
The following PostScript commands should not be used:
initgraphics, erasepage, copypage, grestoreall, initmatrix,
initclip, banddevice, framedevice, nulldevice and renderbands.
Note that the number of pages in a document and the page numbers
on which various sections fall will likely differ in the ASCII and
the PostScript versions. Thus cross references in the text by
section number usually are easier to keep consistent than cross
references by page number.
These PostScript rules are likely to be changed and expanded as
experience is gained.
EID 8054 (Verified) is as follows:Section: 3b
Original Text:
These PostScript rules are likely to changed and expanded as
experience is gained.
Corrected Text:
These PostScript rules are likely to be changed and expanded as
experience is gained.
Notes:
Missing word: "be"
RFCs in PostScript Format may be submitted to the RFC Editor in
e-mail messages (or as online files). If you plan to submit a
document in PostScript please consult the RFC Editor first.
Note that since the ASCII text version of the RFC is the primary
version, the PostScript version must match the text version. The
RFC Editor must decide if the PostScript version is "the same as"
the ASCII version before the PostScript version can be published.
4. Headers and Footers
There is the first page heading, the running headers, and the running
footers.
4a. First Page
Please see the front page of this memo for an example of the front
page heading. On the first page there is no running header. The
top of the first page has the following items:
Network Working Group
The traditional heading for the group that founded the RFC
series. This appears on the first line on the left hand side
of the heading.
Request for Comments: nnnn
Identifies this as a request for comments and specifies the
number. Indicated on the second line on the left side. The
actual number is filled in at the last moment before
publication by the RFC Editor.
Author
The author's name (first initial and last name only) indicated
on the first line on the right side of the heading.
Organization
The author's organization, indicated on the second line on the
right side.
Date
This is the Month and Year of the RFC Publication. Indicated on
the third line on the right side.
Updates or Obsoletes
If this RFC Updates or Obsoletes another RFC, this is indicated
as third line on the left side of the heading.
Category
The category of this RFC, one of: Standards Track, Best Current
Practice, Informational, or Experimental. This is indicated on
the third (if there is no Updates or Obsoletes indication) or
fourth line of the left side.
Other Numbers
Other numbers in the RFC series of notes include the subseries
of FYI (For Your Information) [4], BCP (Best Current Practice)
[5], and STD (Standard) [6]. These are placed on the left
side.
Title
The title appears, centered, below the rest of the heading.
Periods or "dots" in the titles are not allowed.
If there are multiple authors and if the multiple authors are from
multiple organizations the right side heading may have additional
lines to accommodate them and to associate the authors with the
organizations properly.
4b. Running Headers
The running header in one line (on page 2 and all subsequent
pages) has the RFC number on the left (RFC NNNN), the (possibly
nshortened form) title centered, and the date (Month Year) on the
right.
4c. Running Footers
The running footer in one line (on all pages) has the author's
last name on the left, category centered, and the page number on
the right ([Page N]).
5. Status Section
Each RFC must include on its first page the "Status of this Memo"
section which contains two elements: (1) a paragraph describing the
type of the RFC, and (2) the distribution statement.
The content of this section will be one of the four following
statements.
Standards Track
"This document specifies an Internet standards track protocol for
the Internet community, and requests discussion and suggestions
for improvements. Please refer to the current edition of the
"Internet Official Protocol Standards" (STD 1) for the
standardization state and status of this protocol. Distribution
of this memo is unlimited."
Best Current Practice
"This document specifies an Internet Best Current Practices for
the Internet Community, and requests discussion and suggestions
for improvements. Distribution of this memo is unlimited."
Experimental
"This memo defines an Experimental Protocol for the Internet
community. This memo does not specify an Internet standard of any
kind. Discussion and suggestions for improvement are requested.
Distribution of this memo is unlimited."
Informational
"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."
6. Copyright Notice
Immediately following the Status section the statement, "Copyright
(C) The Internet Society (date). All Rights Reserved." is placed.
Also, see Section 11 for the full statement that must appear at the
end of the document.
7. Introduction Section
Each RFC should have an Introduction section that (among other
things) explains the motivation for the RFC and (if appropriate)
describes the applicability of the protocol described.
Normally, this will be the "abstract" section from the Internet
Draft. If the RFC is not based on an I-D, other possibilities
are:
Protocol
This protocol is intended to provide the bla-bla service,
and be used between clients and servers on host computers.
Typically the clients are on workstation hosts and the
servers on mainframe hosts.
or
This protocol is intended to provide the bla-bla service,
and be used between special purpose units such as terminal
servers or routers and a monitoring host.
Discussion
The purpose of this RFC is to focus discussion on particular
problems in the Internet and possible methods of solution.
No proposed solutions in this document are intended as
standards for the Internet. Rather, it is hoped that a
general consensus will emerge as to the appropriate solution
to such problems, leading eventually to the adoption of
standards.
Interest
This RFC is being distributed to members of the Internet
community in order to solicit their reactions to the
proposals contained in it. While the issues discussed may
not be directly relevant to the research problems of the
Internet, they may be interesting to a number of researchers
and implementers.
Status Report
In response to the need for maintenance of current
information about the status and progress of various
projects in the Internet community, this RFC is issued for
the benefit of community members. The information contained
in this document is accurate as of the date of publication,
but is subject to change. Subsequent RFCs will reflect such
changes.
These paragraphs need not be followed word for word, but the
general intent of the RFC must be made clear.
8. References Section
Nearly all RFCs contain citations to other documents, and these are
listed in a References section near the end of the RFC. There are
many styles for references, and the RFCs have one of their own.
Please follow the reference style used in recent RFCs. See the
reference section of this RFC for an example. Please note that for
protocols that have been assigned STD numbers, the STD number must be
included in the reference.
In many standards track documents several words are used to signify
the requirements in the specification. These words are often
capitalized. BCP 14, RFC 2119 [3], defines these words as they
should be interpreted in IETF documents.
9. Security Considerations Section
All RFCs must contain a section near the end of the document that
discusses the security considerations of the protocol or procedures
that are the main topic of the RFC.
10. Author's Address Section
Each RFC must have at the very end a section giving the author's
address, including the name and postal address, the telephone number,
(optional: a FAX number) and the Internet email address.
11. Copyright Section
Per BCP 9, RFC 2026 [2], "The following copyright notice and
disclaimer shall be included in all ISOC standards-related
documentation." The following statement should be placed on the last
page of the RFC, as the "Full Copyright Statement".
"Copyright (C) The Internet Society (date). All Rights Reserved.
This document and translations of it may be copied and furnished
to others, and derivative works that comment on or otherwise
explain it or assist in its implementation may be prepared, copied,
published and distributed, in whole or in part, without
restriction of any kind, provided that the above copyright notice
and this paragraph are included on all such copies and derivative
works. However, this document itself may not be modified in any
way, such as by removing the copyright notice or references to the
Internet Society or other Internet organizations, except as needed
for the purpose of developing Internet standards in which case the
procedures for copyrights defined in the Internet Standards
process must be followed, or as required to translate it into
languages other than English.
The limited permissions granted above are perpetual and will not
be revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on
an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
12. Relation to other RFCs
Sometimes an RFC adds information on a topic discussed in a previous
RFC or completely replaces an earlier RFC. There are two terms used
for these cases respectively, Updates and Obsoletes. A document that
obsoletes an earlier document can stand on its own. A document that
merely updates an earlier document cannot stand on its own; it is
something that must be added to or inserted into the previously
existing document, and has limited usefulness independently. The
terms Supercedes and Replaces are no longer used.
Updates
To be used as a reference from a new item that cannot be used
alone (i.e., one that supplements a previous document), to refer
to the previous document. The newer publication is a part that
will supplement or be added on to the existing document; e.g., an
addendum, or separate, extra information that is to be added to
the original document.
Obsoletes
To be used to refer to an earlier document that is replaced by
this document. This document contains either revised information,
or else all of the same information plus some new information,
however extensive or brief that new information is; i.e., this
document can be used alone, without reference to the older
document.
For example:
On the Assigned Numbers RFCs the term Obsoletes should be used
since the new document actually incorporate new information
(however brief) into the text of existing information and is
more up-to-date than the older document, and hence, replaces it
and makes it Obsoletes.
In lists of RFCs or the RFC-Index (but not on the RFCs themselves)
the following may be used with early documents to point to later
documents.
Obsoleted-by
To be used to refer to the newer document(s) that replaces the
older document.
Updated-by
To be used to refer to the newer section(s) which are to be added
to the existing, still used, document.
13. Protocol Standards Process
See the current "Internet Official Protocol Standards" (STD 1) memo
for the definitive statement on protocol standards and their
publication [1].
The established procedure is that when the IESG completes work on a
document that is to become a standards track RFC the communication
will be from the Secretary of the IESG to the RFC Editor. Generally,
the documents in question are Internet Drafts. The communication
usually cites the exact Internet Draft (by file name) in question.
The RFC Editor must assume that only that file is to be processed to
become the RFC. If the authors have small corrections to the text,
they should be sent to the RFC Editor separately (or as a "diff"), do
not send a new version of the document.
14. Contact
To contact the RFC Editor send an email message to:
"rfc-editor@isi.edu".
15. Distribution Lists
The RFC announcements are distributed via two mailing lists: the
"IETF-Announce" list, and the "RFC-DIST" list. You don't want to be
on both lists.
To join (or quit) the IETF-Announce list send a message to ietf-
request@ietf.org.
To join (or quit) the RFC-DIST list send a message to rfc-dist-
request@isi.edu.
16. RFC Index
Several organizations maintain RFC Index files, generally using the
file name "rfc-index.txt". The contents of such a file copied from
one site may not be identical to that copied from another site.
17. Security Considerations
This RFC raises no security issues (however, see Section 9).
18. References
[1] Postel, J., Editor, "Internet Official Protocol Standards", STD
1, RFC 2200, June 1997.
[2] Bradner, S., "The Internet Standards Process -- Revision 3", BCP
9, RFC 2026, October 1996.
[3] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[4] Malkin, G., and J. Reynolds, "F.Y.I. on F.Y.I Introduction to
the F.Y.I. Notes", FYI 1, RFC 1150, March 1990.
[5] Postel, J., Li, T., and Y. Rekhter, "Best Current Practices",
BCP 1, RFC 1818, August 1995.
[6] Postel, J., Editor, "Introduction to the STD Notes", RFC 1311,
March 1992.
19. Authors' Addresses
Jon Postel
USC/Information Sciences Institute
4676 Admiralty Way
Marina del Rey, CA 90292
Phone: +1 310-822-1511
Fax: +1 310-823-6714
EMail: Postel@ISI.EDU
Joyce K. Reynolds
USC/Information Sciences Institute
4676 Admiralty Way
Marina del Rey, CA 90292
Phone: +1 310-822-1511
Fax: +1 310-823-6714
EMail: jkrey@isi.edu
20. Appendix - RFC "nroff macros"
Generally, we use the very simplest nroff features. We use the "ms"
macros. So, "nroff -ms input-file > output-file". However, we could
not get nroff to do the right thing about putting a form feed after
the last visible line on a page and no extra line feeds before the
first visible line of the next page. We want:
last visible line on page i
^L
first visible line on page i+1
So, we invented a hack to fix this. We use a perl script called
"fix.pl". So the command to process the file becomes:
nroff -ms input-file | fix.pl > output-file
The actual perl script is:
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#! /local/bin/perl
# fix.pl 17-Nov-93 Craig Milo Rogers at USC/ISI
#
# The style guide for RFCs calls for pages to be delimited by the
# sequence <last-non-blank-line><formfeed-line><first-non-blank-line>.
# Unfortunately, NROFF is reluctant to produce output that conforms to
# this convention. This script fixes RFC-style documents by searching
# for the token "FORMFEED[Page", replacing "FORMFEED" with spaces,
# appending a formfeed line, and deleting white space up to the next
# non-white space character.
#
# There is one difference between this script's output and that of
# the "fix.sh" and "pg" programs it replaces: this script includes a
# newline after the formfeed after the last page in a file, whereas the
# earlier programs left a bare formfeed as the last character in the
# file. To obtain bare formfeeds, uncomment the second substitution
# command below. To strip the final formfeed, uncomment the third
# substitution command below.
#
# This script is intended to run as a filter, as in:
#
# nroff -ms input-file | fix.pl > output-file
#
# When porting this script, please observe the following points:
#
# 1) ISI keeps perl in "/local/bin/perl"; your system may keep it
# elsewhere.
# 2) On systems with a CRLF end-of-line convention, the "\n"s below
# may have to be replaced with "\r\n"s.
$* = 1; # Enable multiline patterns.
undef $/; # Read whole files in a single
# gulp.
while (<>) { # Read the entire input file.
s/FORMFEED(\[Page\s+\d+\])\s+/ \1\n\f\n/g;
# Rewrite the end-of-pages.
# s/\f\n$/\f/; # Want bare formfeed at end?
# s/\f\n$//; # Want no formfeed at end?
print; # Print the resultant file.
}
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This script can also be copied from: ftp://ftp.isi.edu/in-notes/rfc-
editor/fix.pl
Now as to the nroff features we actually use, following is a sample
memo, prepared in RFC style.
.pl 10.0i
.po 0
.ll 7.2i
.lt 7.2i
.nr LL 7.2i
.nr LT 7.2i
.ds LF Waitzman
.ds RF PUTFFHERE[Page %]
.ds CF
.ds LH RFC 1149
.ds RH 1 April 1990
.ds CH IP Datagrams on Avian Carriers
.hy 0
.ad l
.in 0
Network Working Group D. Waitzman
Request for Comments: 1149 BBN STC
1 April 1990
.ce
A Standard for the Transmission of IP Datagrams on Avian Carriers
.ti 0
Status of this Memo
.fi
.in 3
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.
.ti 0
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.
.ti 0
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.
.ti 0
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.
.ti 0
Security Considerations
.in 3
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.
.ti 0
Author's Address
.nf
David Waitzman
BBN Systems and Technologies Corporation
BBN Labs Division
10 Moulton Street
Cambridge, MA 02238
Phone: (617) 873-4323
EMail: dwaitzman@BBN.COM
21. Full Copyright Statement
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