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Independent Submission H. Kaplan
Request for Comments: 8369 128 Technology
Category: Informational 1 April 2018
ISSN: 2070-1721
Internationalizing IPv6 Using 128-Bit Unicode
Abstract
It is clear that Unicode will eventually exhaust its supply of code
points, and more will be needed. Assuming ISO and the Unicode
Consortium follow the practices of the IETF, the next Unicode code
point size will be 128 bits. This document describes how this future
128-bit Unicode can be leveraged to improve IPv6 adoption and finally
bring internationalization support to IPv6.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This is a contribution to the RFC Series, independently of any other
RFC stream. The RFC Editor has chosen to publish this document at
its discretion and makes no statement about its value for
implementation or deployment. Documents approved for publication by
the RFC Editor are not candidates for any level of Internet Standard;
see Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8369.
Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4
2. The Need for 128-Bit Code Points . . . . . . . . . . . . . . 4
3. Unicode IPv6 Addresses . . . . . . . . . . . . . . . . . . . 6
3.1. Reserved Addresses . . . . . . . . . . . . . . . . . . . 6
3.2. Multicast . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3. IPv6 Routing . . . . . . . . . . . . . . . . . . . . . . 7
4. Using Unicode IPv6 Addresses . . . . . . . . . . . . . . . . 8
4.1. Uniform Resource Identifiers . . . . . . . . . . . . . . 8
4.2. Address Allocation and Resolution . . . . . . . . . . . . 8
5. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
7. Security Considerations . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.1. Normative References . . . . . . . . . . . . . . . . . . 10
8.2. Informative References . . . . . . . . . . . . . . . . . 10
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 11
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 11
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1. Introduction
Unicode [Unicode] is currently limited to 1,114,112 code points,
encoded in various encoding formats (e.g., UTF-8, UTF-16, UTF-32).
At the time of this document's publication, 136,755 code points have
been allocated, with more already in the approval process. Every
year, more writing scripts, symbols, and emojis are added, while none
are removed. After consulting expert mathematicians, we have
determined that the world will run out of code points someday in the
future.
While it might appear that the current rate of code point allocation
gives us plenty of time to deal with the exhaustion problem, the
Internet's history has shown that popular number spaces do not fill
up linearly, but rather exponentially. And once the size of a
particular number space becomes entrenched, it takes decades to
migrate to a larger one. Therefore, the code point number space must
be increased as soon as possible.
The details for expanding the Unicode code point space are not
covered in this document. Such details need to be worked out between
the IETF, ISO, the Unicode Consortium, and various gods. We assume,
however, that the code point space will need to grow dramatically,
and there will continue to be a need for a fixed-length encoding
scheme similar to UTF-32. Naturally, the next size increment should
go from UTF-32 to UTF-128, and thus the rest of this document follows
this assumption.
This new 128-bit Unicode code point space can be leveraged by the
IETF to address one of the lingering issues with IPv6: there's not
much left to standardize. With the changes described in this
document, the IETF will be kept busy for decades to come. It also
enables new features and market opportunities, to help the global
economy. This in turn will increase tax revenues for governments,
which eventually may lead to increased funds for combating global
warming. Therefore, the ultimate goal of this document is to reduce
global warming.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. All other words SHOULD be interpreted as
described by the Oxford English Dictionary OED [OED], which MAY be
considered almost as authoritative for word definitions as the IETF.
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1.2. Definitions
UTF-128: A fixed-length encoding for 128-bit Unicode. It is
implemented as an array of bytes in the same manner as legacy
IPv6 addresses to avoid endianness issues.
Short-Name Tag: A short descriptive name for a Unicode character
code point, surrounded by colons (:). For example ":garfield:"
represents the Unicode code point for the Garfield cat imoji.
Emoji: Pictographic symbol encoded in Unicode, used to express a
general item, concept, or emotion.
Imoji: Pictographic symbol encoded in Unicode, used to represent an
individual, specific thing: a specific human, a favorite pet, a
famous animal, etc.
Amoji: Pictographic symbol encoded in Unicode, used to represent an
individual of an alien species.
Umoji: Pictographic symbol encoded in Unicode, used to represent
unknown things not covered by the other mojis.
Omoji: Pictographic symbol encoded in Unicode, used to represent
obfuscated identities, used as addresses for the purpose of
privacy.
2. The Need for 128-Bit Code Points
The exponentially increasing demand for Unicode character code points
might not be obvious at first glance. While it is true that the
number of languages and their writing scripts do not grow quickly
over time, one type of "character" will: emojis. Unicode has barely
begun providing code points for all of the various emojis currently
in use, and it is likely that more emojis will be created in the
future. For example, there are still missing emoji symbols for most
types of food and drink, the flags of each town and city on Earth,
all human sporting and leisure activities including all local and
national sports teams and players, and every plant and animal species
and gender.
Furthermore, it has become common for some applications to allow
their users to create custom emojis, whereby the user can provide the
graphic to display for a new "character". For example, a user might
set their chat application to display a graphic of Carlos Ramirez's
popular "Trollface" meme [TROLL], using the short-name tag
':trollface:' in their chat application. All other users of the same
chat app will be able to see and use the same custom trollface emoji.
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However, since there is no Unicode code point for :trollface:, the
chat app cannot export the trollface emoji to other chat apps or
protocols, such as Internet Relay Chat (IRC) or the Extensible
Messaging and Presence Protocol (XMPP). This represents a clear
interoperability issue.
In the future, it might also become desirable to assign each human a
Unicode code point to represent them, similar to names, with the
glyph being a picture of their face or a custom graphic. These
personal code points are not truly "emojis" in the classical sense of
being generic concepts, so we've decided to give them a new name to
avoid confusion: imoji. Unlike human names, code points for imojis
will be unique per human, for all space and time. Favorite pets and
famous animals can also be assigned imojis.
Lastly, if we ever encounter sentient species from other planets,
they too will need Unicode code points for their writing scripts and
emojis; and they will each need unique amojis (imojis for aliens),
for whatever form their individual identity might take. Section 4 of
RFC 8136 [RFC8136] clearly supports such a scenario, with the new UFO
IPv6 option.
Based on the above obvious use cases, it is clear that the current ~1
million code points are nowhere near enough. Increasing to 64 bits
might be sufficient for now, but since this will be a painful
transition process no matter the size, we believe jumping to 128 bits
is the appropriate choice.
Note: The current limit of ~1 million code points is a formal limit
due to what UTF-16 can encode today. Increasing the limit will
either require deprecating UTF-16 or paying a hefty overhead penalty
to encode 128 bits across many pairs of surrogate code points. Since
the ultimate goal of this document is to reduce global warming, the
challenge of choosing between deprecating UTF-16 or paying the
overhead price is a trivial dilemma to solve by comparison.
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3. Unicode IPv6 Addresses
Assuming the new Unicode code point space is 128 bits -- excluding
some reserved bits for backwards compatibility and future expansion
-- it seems only natural to use Unicode code points for IPv6
addresses, and vice versa. This leads to some exciting changes, such
as:
o IPv6 addresses no longer need to be typed as hex values --
instead, the glyph for the script character, symbol, emoji, or
imoji representing that address can be input by the user, and it
will be displayed by the application as the graphic itself. From
the user's perspective, this will also be more compact than the
representation described in RFC 1924 [RFC1924].
o Network monitoring and troubleshooting tools can now display
pretty glyphs in place of ugly IPv6 addresses, leading to less
stress on the eyes of network administrators.
o For cases where graphical glyphs cannot be used, such as IETF
documents, we can deprecate the legacy textual notation of IPv6
addresses of the style '2001:db8:85a3::8a2e:370:7334' to the
simpler Unicode textual notation
'U+20010DB885A3000000008A2E03707334'. Using the short-name tag is
also possible, such as ':v6address-1:'.
Due to the nature of having IPv6 addresses be Unicode code points,
RFC 8135 [RFC8135] is made obsolete by this document. It was found
to be too complex to implement anyway.
3.1. Reserved Addresses
Some address code points will be inappropriate for IPv6 addressing,
such as formatting characters and control codes. Such code points
MUST NOT be used for IPv6 addresses.
We do, however, still need to reserve some code points for private
network use. Since no sentient life has been found on Mars, the code
points that would have been allocated for Martian imojis are hereby
allocated for this private use. These addresses are thus called
"Martians", also known as "Bogons" due to them being bogus.
Note: Should life be found on Mars in the future, new code points
will be allocated for them. To avoid confusion, they will be called
"Barsoom Indigenous Glyph Off-world Network" addresses, or "Bigons"
(pronounced "bye-gons"). We're certain the Martians will let Bogons
be bygones, and Bigons be Bigons.
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3.2. Multicast
In both IPv4 and IPv6, multicast addresses have been relegated to
predefined IP address ranges, limiting how many multicast groups
could be used simultaneously. Given the rise of broadcasting-style
social media platforms, and the market demand for individuals to be
watched/followed by numerous random strangers constantly, it seems
clear that we need to be able to multicast everything, all the time.
To address this need, the high-order bit of the 128-bit code point
space SHALL be reserved to indicate multicast. All valid code points
(i.e., IPv6 addresses) will thus have multicast counterparts. For
example, the code point allocated for :cat: is U+1F408. The
multicast group U+8000000000000000000000000001F408 is thus for
content about cats. Note that this is for general cat content --
other code points are allocated for specific cat content, such as joy
cat, grinning cat, pouty cat, etc. For an individual cat like
Garfield, setting the high-order bit to the code point allocated for
:garfield: will indicate that it is multicast content about Garfield.
Source-specific multicast also plays a role; for example, joining the
:garfield: multicast group and restricting it to a source of
:garfield: results in only receiving content about Garfield, from
Garfield.
3.3. IPv6 Routing
There should be little impact on routing using code-point-based IPv6
addresses. There might be some exponential growth in routing and
forwarding tables due to difficulties in aggregating code points;
hopefully, this will be offset by increases in processor and memory
capacity. Of course this will also drive the need to frequently
upgrade networking hardware, resulting in a boost to the global
economy, and thus a reduction in global warming.
One improvement to routing that MAY be considered is for scenic
routing as defined by RFC 7511 [RFC7511]. With emojis and imojis
being available for addressing, we can now specify which exact type
of scenery to visit along the way, or even which exact avian carrier
[RFC6214] to ride with. Note that avian carriers as described in RFC
1149 [RFC1149] are not supported, since they only support IPv4.
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4. Using Unicode IPv6 Addresses
4.1. Uniform Resource Identifiers
Uniform Resource Identifiers (URIs) and Uniform Resource Locators
(URLs) already support Unicode through Internationalized Resource
Identifiers (IRIs), but these are merely a means to use multiple
Unicode characters to indicate a resource. With 128-bit Unicode, the
number space is large enough to identify each resource with a single
Unicode character. Why waste space and time typing out multiple
characters, when you can just use one?
For URLs, this new model might only mean using a single Unicode
character for the hostname portion -- for example, a corporate logo
in place of the legacy corporate domain name. Another alternative is
to allocate a code point for the entire host and path, possibly even
including the scheme. These types of decisions can be made in future
IETF Working Groups.
The interesting aspect of this change for URIs/URLs is that no
address lookup needs to be performed. The single 128-bit Unicode for
the URL *is* the IPv6 address. An additional step is only needed if
the user inputs a private Unicode character or short-name tag that
needs to be converted to a publicly allocated one. This would
require Network Address Translation (NAT) from the private code point
or short-name tag to a public Unicode code point. This can be done
locally, thus finally bringing NATs into the last part of the
Internet in which they are not currently deployed: the user's
application.
4.2. Address Allocation and Resolution
It is obvious that once a single 128-bit Unicode character is used
for addresses and URIs, using domain names will quickly become
obsolete. The subsequent collapse of the domain name industry
presents a threat to the world economy, which MUST be addressed.
One solution to this danger is to establish a Unicode registry model
and an accompanying Code Point Unicode Resolution System (CPURS,
pronounced "keepers"). CPURS would replace DNS and provide an
architecture and resolution mechanism to resolve Unicode code points
to their registered glyphs and short-name tags, and vice versa. The
new Unicode registries and registrars would thus replace the legacy
domain name counterparts. This would lead to a new gold rush for
registering Unicode code points for corporate logos and product
icons, and thus usher in an era of economic prosperity, which would
eventually reduce global warming.
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Once Unicode registries and CPURS are in place, IPv6 addresses would
be allocated by registering code points through that system; they
would no longer be registered by IANA and RIRs. This is not a major
concern, however, because any tax revenue loss will be more than
offset by Unicode registries allocating code points. Furthermore, in
order to make CPURS possible, the actual graphic files for the glyphs
need to be standardized and created in numerous formats and sizes,
with various intellectual property rules. This will provide more
work for graphic artists and lawyers, further increasing tax revenue.
The astute reader might ask why we need CPURS if Unicode translation
is performed locally on hosts today. The answer is volume: it is
unlikely that host applications can keep up with the rate of new
Unicode code points being allocated for emojis, imojis, and umojis.
While application and operating system updates have been occurring at
an ever-increasing rate, and will soon reach the same rate as human
births, it is doubtful that it will ever reach the rate of sentient
extraterrestrial births. Therefore, we need a system that can scale
to reach such volume before we make first contact; otherwise, the
diplomatic failure to quickly provide the aliens with amojis of their
own may lead to armed conflict. An armed conflict with other
sentient beings capable of reaching Earth might increase global
warming, defeating this document's ultimate purpose.
5. Summary
There is still much to be decided on, most of which is frankly rather
boring. It is clear, however, that 128-bit Unicode code points will
be needed eventually, and IPv6 addressing MUST be migrated to it.
Thus, the time to act is now!
6. IANA Considerations
This document has no IANA actions.
7. Security Considerations
The main security concern with using 128-bit Unicode for IPv6
addressing is the need for privacy, in terms of anonymity. If an
IPv6 packet is sent with an imoji or amoji address, then man-in-the-
middle devices in the network will know the specific human or alien
that sent or received the packet. Using such information might lead
to heated discussions, thereby increasing global warming.
To address this concern, an IPv6 address MAY be obfuscated by using
an omoji. An omoji is simply the original Unicode code point but
with the least-significant bit set; all other types of 128-bit
Unicode code points MUST have the least-significant bit cleared. The
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graphical representation of an omoji is the same as its unobfsucated
moji counterpart, except that it is covered over by a solid black
block.
By setting the least-significant bit of the source or destination and
thus turning it into an omoji, the IPv6 address is obfuscated and the
true identity cannot be determined, while IPv6 routers can still
route the packet appropriately. Note that this only provides a bit
of privacy, but every bit helps.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
8.2. Informative References
[OED] Oxford University Press, "Oxford English Dictionary",
<http://www.oed.com>.
[RFC1149] Waitzman, D., "Standard for the transmission of IP
datagrams on avian carriers", RFC 1149,
DOI 10.17487/RFC1149, April 1990,
<https://www.rfc-editor.org/info/rfc1149>.
[RFC1924] Elz, R., "A Compact Representation of IPv6 Addresses",
RFC 1924, DOI 10.17487/RFC1924, April 1996,
<https://www.rfc-editor.org/info/rfc1924>.
[RFC6214] Carpenter, B. and R. Hinden, "Adaptation of RFC 1149 for
IPv6", RFC 6214, DOI 10.17487/RFC6214, April 2011,
<https://www.rfc-editor.org/info/rfc6214>.
[RFC7511] Wilhelm, M., "Scenic Routing for IPv6", RFC 7511,
DOI 10.17487/RFC7511, April 2015,
<https://www.rfc-editor.org/info/rfc7511>.
[RFC8135] Danielson, M. and M. Nilsson, "Complex Addressing in
IPv6", RFC 8135, DOI 10.17487/RFC8135, April 2017,
<https://www.rfc-editor.org/info/rfc8135>.
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[RFC8136] Carpenter, B. and R. Hinden, "Additional Transition
Functionality for IPv6", RFC 8136, DOI 10.17487/RFC8136,
April 2017, <https://www.rfc-editor.org/info/rfc8136>.
[TROLL] The Meme Wikia, "Trollface",
<http://meme.wikia.com/wiki/Rule_63?oldid=23602>.
[Unicode] The Unicode Consortium, "Unicode", <http://unicode.org>.
Acknowledgements
The authors wish to thank the following people for providing the
inspiration for this work: Cal Henderson, Carlos Ramirez, Graham
Linehan, Agnetha Faltskog, Bjorn Ulvaeus, Benny Andersson, and
Anni-Frid Lyngstad.
Author's Address
Hadriel Kaplan
128 Technology
Burlington, MA
United States of America
Email: hadriel@128technology.com
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