Network Working Group T. Kalin
Request for Comments: 4926 M. Molina
Category: Informational DANTE
July 2007
A URN Namespace for GEANT
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This document describes a proposed URN (Uniform Resource Name)
namespace that would be managed by DANTE, representing European
Research and academic networks, for naming persistent resources
defined by GEANT, the Consortium of European Academic and Research
Networks, its projects, activities, working groups, and other
designated subordinates.
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RFC 4926 A URN Namespace for GEANT July 2007
1. Introduction
The Consortium of European Academic and Research Networks (GEANT)
provides high-speed, high-quality network connectivity for education
institutions, universities, and research centres in Europe. The
network infrastructure is composed of several National Research and
Education Networks (NRENs) and their European-wide interconnection,
GEANT. The current network is GEANT2 [6], and is the seventh
generation of pan-European research and education network, successor
to the pan-European multi-gigabit research network GEANT. DANTE [7]
is a UK-based organization representing the members of the Consortium
and operating the GEANT2 Network. This cooperative work is mainly
done in the framework of EU-funded projects. The biggest of such
activities is currently the GN2 project [6], started in September
2004, that follows other successful ones that have evolved the
European Networks for Research and Education for almost two decades.
It is expected that these activities and the network evolution will
continue to be supported by the European Union and all European
governments in the years to come, as they view the existence of a
state-of-the-art network for research in Europe as being of top
strategic importance. We will refer to the organization involved in
these projects and those that benefit from their outcome as the
"GEANT community".
The GEANT community produces many kinds of documents: specifications,
working drafts, project reports, schemas, stylesheets, etc. The
community wishes to provide global, distributed, persistent,
location-independent names for these resources. The Uniform Resource
Name (URN) variant of URIs meets these requirements.
The GEANT community and other GEANT-affiliated groups would benefit
from the GEANT URN proposal by having an easy, efficient way to
assign globally unique, persistent identifiers to resources that they
create. The nature of GEANT work is that it serves the needs of many
communities of interest. A namespace managed so as to facilitate the
creation, registration, and resolution of unique, persistent
identifiers would be of great value for GEANT, its affiliates, and
the higher education community generally. The possibility of fitting
the naming needs under existing namespaces has been considered, but
the conclusion was that the number of activities and the size of the
developers community is such that creating a lot of (possibly
uncoordinated) dependencies from other namespaces is undesirable.
The proposed URN namespace specification is for a formal namespace.
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2. Specification Template
Namespace ID:
geant
Registration Information:
Registration Version Number 1
Registration Date: 2006-03-21
Registrant of the namespace:
DANTE
ATTN: Maurizio Molina
City House
126 - 130 Hills Road
Cambridge CB2 1PQ
United Kingdom
Phone: +44 1223 371340
Contact: Tomaz Kalin
Affiliation: DANTE
City House
126 - 130 Hills Road
Cambridge CB2 1PQ
Email:
[email protected]
Phone: +386 1 430 3055
Syntactic structure:
The Namespace Specific Strings (NSS) of all URNs assigned by
GEANT will conform to the syntax defined in section 2.2 of RFC
2141, "URN Syntax" [2]. In addition, all GEANT URN NSSs will
consist of a left-to-right series of tokens delimited by
colons. The left-to-right sequence of colon-delimited tokens
corresponds to descending nodes in a tree. To the right of the
lowest naming authority node, there may be zero, one, or more
levels of hierarchical naming nodes terminating in a rightmost
leaf node. See the section below entitled "Identifier
assignment" for more on the semantics of NSSs. This syntax
convention is captured in the following normative ABNF rules
for GEANT NSSs (see RFC 4234 [1]):
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RFC 4926 A URN Namespace for GEANT July 2007
GEANT-NSS = 1*(subStChar) 0*(":" 1*(subStChar))
subStChar = trans / "%" HEXDIG HEXDIG
trans = ALPHA / DIGIT / other / reserved
other = "(" / ")" / "+" / "," / "-" / "." /
"=" / "@" / ";" / "$" /
"_" / "!" / "*" / "'"
reserved = "%" / "/" / "?" / "#"
The exclusion of the colon from the list of "other" characters
means that the colon can only occur as a delimiter between
string tokens. Note that this ABNF rule set guarantees that
any valid GEANT NSS is also a valid RFC 2141 NSS.
Relevant ancillary documentation:
None.
Identifier uniqueness:
It is the responsibility of DANTE to guarantee uniqueness of
the names of immediately subordinate naming authorities. Each
lower-level naming authority in turn inherits the
responsibility of guaranteeing uniqueness of names in their
branch of the naming tree.
Identifier persistence:
DANTE bears ultimate responsibility for maintaining the
usability of GEANT URNs over time. This responsibility may be
delegated to subordinate naming authorities per the discussion
in the section below on identifier assignment. That section
provides a mechanism for the delegation to be revoked in the
case a subordinate naming authority ceases to function.
Identifier assignment:
DANTE will create an initial series of immediately subordinate
naming authorities, and will define a process for adding to
that list of authorities. Each top-level working group of
GEANT will be invited to designate a naming authority and to
suggest one or more candidate names.
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Institutions and communities affiliated with GEANT may request,
through their designated GEANT liaison, that they be granted
GEANT-subordinate naming authority status. They may propose
candidate names for that authority. One way for such entities
to guarantee uniqueness of their proposed name is to base it on
a DNS name. That is, if, e.g., the German National Research
and Education Network wished to be designated a subordinate
naming authority under GEANT, the institutional GEANT liaison
could propose to DANTE to be delegated control over names
beginning with "urn:geant:dfn.de". Institutions seeking
affiliation with GEANT should send email to
[email protected], nominating an institutional liaison
and providing contact information for that person.
On at least an annual basis, DANTE will contact the liaisons or
directors of each immediately subordinate naming authority. If
there is no response, or if the respondent indicates that they
wish to relinquish naming authority, the authority over that
branch of the tree reverts to GEANT. This process will be
enforced recursively by each naming authority on its
subordinates. This process guarantees that responsibility for
each branch of the tree will lapse for less than one year, at
worst, before being reclaimed by a superior authority.
Lexical equivalence of two GEANT namespace specific strings
(NSSs) is defined below as an exact, case-sensitive string
match. DANTE will assign names of immediately subordinate
naming authorities in lowercase only. This forestalls the
registration of two GEANT-subordinate naming authorities whose
names differ only in case.
Identifier resolution:
DANTE will maintain an index of all GEANT and GEANT workgroup
assigned URNs on its Web site,
http://www.dante.net/urn-geant/urn-geant.html. That index will
map URNs to resource identifiers, usually URLs. GEANT-
affiliated naming authorities will specify how to resolve the
URNs they assign if they are resolvable.
Lexical equivalence:
Lexical equivalence of two GEANT Namespace Specific Strings
(NSSs) is defined as an exact, case-sensitive string match.
Conformance with URN syntax:
All GEANT NSSs fully conform to RFC 2141 syntax rules for NSSs.
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Validation mechanism:
As specified in the "Identifier resolution" section above,
DANTE will maintain an index of all GEANT and GEANT workgroup
assigned URNs on its Web site,
http://www.dante.net/urn-geant/urn-geant.html Presence in that
index implies that a given URN is valid. GEANT-affiliated
naming authorities will specify how to validate the URNs they
assign.
Scope:
Global.
3. Security Considerations
There are no additional security considerations beyond those normally
associated with the use and resolution of URNs in general.
4. Namespace Considerations
Registration of an Namespace Identifier (NID) specific to GEANT is
reasonable given the following considerations:
1. GEANT would like to assign URNs to some very fine-grained
objects. This does not seem to be the primary intended use of
the XMLORG namespace (RFC 3120) [3], or the more tightly
controlled OASIS namespace (RFC 3121) [4].
2. GEANT seeks naming autonomy. GEANT is not a member of OASIS, so
becoming a subordinate naming authority under the OASIS URN space
is not an option.
3. GEANT will want to assign URNs to non-XML objects as well. That
is another reason that XMLORG may not be an appropriate higher-
level naming authority for GEANT.
Some GEANT-developed schema and namespaces may be good candidates for
inclusion in the XMLORG or possible future "EU" registry. The fact
that such an object might already have a GEANT-assigned URN shouldn't
be a hindrance. RFC 3406 [5] (which replaced RFC 2611) includes an
explicit statement that two or more URNs may point to the same
resource. A resource with a GEANT-assigned Namespace Specific String
would, of course, be given an XMLORG or EU Namespace Specific String
as it enters the XMLORG or "EU" registry.
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5. Community Considerations
The assignment and use of identifiers within the namespace are open,
and the related rule is established by DANTE. Registration agencies
(the next level naming authorities) will be the European National
Research and Education Networks and the established organizational
cross-border formations.
It is expected that the majority of the NRENs and all GEANT base
activities make use of the GEANT namespace.
After the establishment of the GEANT namespace, the consortium will,
as soon as practical, establish a resolution service (analogously to
other distributed pan-European services, like EduROAM, PerfSONAR,
etc.) for the namespace clients.
6. IANA Considerations
IANA has registered the "geant" NID within the IANA registry of URN
NIDs.
7. Normative References
[1] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 4234, October 2005.
8. Informative References
[2] Moats, R., "URN Syntax", RFC 2141, May 1997.
[3] Best, K. and N. Walsh, "A URN Namespace for XML.org", RFC 3120,
June 2001.
[4] Best, K. and N. Walsh, "A URN Namespace for OASIS", RFC 3121,
June 2001.
[5] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom, "URN
Namespace Definition Mechanisms", BCP 66, RFC 3406, October
2002.
[6] GEANT2 project's Web site, <
http://www.geant2.net/>.
[7] DANTE's company Web site, <
http://www.dante.net/>.
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Authors' Addresses
T. Kalin
DANTE
City House
126 - 130 Hills Road
Cambridge
CB2 1PQ
United Kingdom
EMail:
[email protected]
Maurizio Molina
DANTE
City House
126 - 130 Hills Road
Cambridge
CB2 1PQ
United Kingdom
EMail:
[email protected]
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RFC 4926 A URN Namespace for GEANT July 2007
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