X.500
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... directory services, the
limitations of current models, and some solutions provided by the
X.500 standard to these limitations.
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... search the .plan files on a given host to (for example) find
everyone on mazatzal.merit.edu who works on X.500. Thus, fingerd has
a limited usefulness as a piece of the Internet Directory.
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... THE X.500 MODEL OF DIRECTORY SERVICE ...
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X.500 is a CCITT protocol which is designed to build a distributed,
global directory. It offers the following features:
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... Decentralized Maintenance:
Each site running X.500 is responsible ONLY for its local part
of the Directory, so updates and maintenance can be done instantly.
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... Powerful Searching Capabilities:
X.500 provides powerful searching facilities that allow users to
construct arbitrarily complex queries.
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... Single Global Namespace:
Much like the DNS, X.500 provides a single homogeneous namespace
to users. The X.500 ...
... X.500 provides a single homogeneous namespace
to users. The X.500 namespace is more flexible and expandable
than the DNS ...
... Structured Information Framework:
X.500 defines the information framework used in the directory,
allowing local extensions.
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... Standards-Based Directory:
As X.500 can be used to build a standards-based directory,
applications which require directory information (e-mail,
automated resource locators, special-purpose directory tools ...
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The '88 version of the X.500 standard talks about 3 models required
to build the X.500 Directory Service: the Directory Model, the
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... version of the X.500 standard talks about 3 models required
to build the X.500 Directory Service: the Directory Model, the
Information Model, and the Security Model. In this section, we will
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... Security Model. In this section, we will
provide a brief overview of the Directory and Information Models
sufficient to explain the vast functionality of X.500.
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The attribute syntax for the surName attribute would be
CaseIgnoreString, which would tell X.500 that surName could contain
any string, and case would not matter; the attribute syntax for the
telephoneNumber ...
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At this point in our description of the information model, we have no
way of knowing what type of object a given entry represents. X.500
uses the concept of an "object class" to specify that information,
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Each object class in X.500 has a definition which lists the set of
mandatory attributes, which must be present, and a set of optional
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The object classes in X.500 are arranged in a hierarchical manner
according to class inheritance; the following diagram shows a part of
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... tree
could use more than one attribute to build its RDN. X.500 also allows
the use of alias names, so that the entry {c=us, o=Merit, cn=Chris
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... The functionality of X.500 ...
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To describe the functionality of X.500, we will need to separate
three stages in the evolution of X.500: 1) the 1988 standard, 2)
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... To describe the functionality of X.500, we will need to separate
three stages in the evolution of X.500: 1) the 1988 standard, 2)
X.500 as implemented in QUIPU, and 3) the (proposed) 1992 standard.
...
... three stages in the evolution of X.500: 1) the 1988 standard, 2)
X.500 as implemented in QUIPU, and 3) the (proposed) 1992 standard.
We will list some of the features described in the 1988 standard,
show how they were implemented in QUIPU, and discuss where the 1992
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... a) it is widely used in the U.S. and European Directory Services
Pilot projects, and b) it works well. For a survey of other X.500
implementations and a catalogue of DUAs, see [Lang].
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... Functionality in X.500 (88) ...
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There are a number of advantages that the X.500 Directory accrues
simply by virtue of the fact that it is distributed, not limited to a
single machine. Among these are:
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The functionality built into the X.500(88) standard includes:
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... (313) area code or an e-mail address ending in umich.edu.
This feature of X.500 also helps to provide the basic
functionality for a Yellow Pages service.
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... Security issues.
The X.500 (88) standards define two types of security for
Directory data: Simple Authentication ...
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In addition to the global benefits of the X.500 standard, there are
many local benefits. One can use their local DSA for company ...
... Michigan is providing all the campus directory services through
X.500. The DUAs are available for a wide range of platforms,
including X-Windows systems and Macintoshes ...
...
Functionality beyond the X.500 (88) standard implemented by QUIPU
includes:
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... Current limitations of the X.500 standard and implementations. ...
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As flexible and forward looking as X.500 is, it certainly was not
designed to solve everyone's needs for all time to come. X.500 is not
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... As flexible and forward looking as X.500 is, it certainly was not
designed to solve everyone's needs for all time to come. X.500 is not
a general purpose database, nor is it a Data Base ...
... Data Base Management System
(DBMS). X.500 defines no standards for output formats, and it
certainly doesn't have a report generation capability. The technical
mechanisms are not yet in place for the Directory to contain
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... DIT, or on the idea structure of the object tree. This can make
it hard to add to the current corpus of X.500 work, and the number of
RFCs on various aspects of the X.500 deployment ...
... it hard to add to the current corpus of X.500 work, and the number of
RFCs on various aspects of the X.500 deployment is growing monthly.
...
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Despite this, however, X.500 is very good at what it was designed to
do; i.e., to provide primary directory services and "resource
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... Things to be added in X.500 (92). ...
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The 1988 version of the X.500 standard proved to be quite sufficient
to start building a Directory Service ...
... Directory Service. However, many of the new
functions implemented in QUIPU were necessary if the Directory were
to function in a reasonable manner. X.500 (92) will include
formalized and standardized versions of those advances, including
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... Current applications of X.500 ...
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X.500 is filling Directory Services needs in a large number of
countries. As a directory to locate people, it is provided in the
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... needing a directory service (particularly for distributed directory
services), X.500 is either providing those services or being expanded
to provide those services ...
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In particular, X.500 was envisioned by its creators as providing
directory services for electronic mail ...
... everyone at the University has a unified mail address, e.g.
Chris.Weider@umich.edu. An X.500 server then reroutes that mail to
the appropriate user's real mail address in a transparent fashion.
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... the appropriate user's real mail address in a transparent fashion.
Similarly, Sprint is using X.500 to administrate the address space
for its internal X.400 ...
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Those of us working on X.500 feel that X.500's strengths lie in
providing directory services ...
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Those of us working on X.500 feel that X.500's strengths lie in
providing directory services for people and objects, and for
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... providing primary resource location for a large number of online
services. We think that X.500 is a major component (though not the
only one) of a global Yellow Pages service ...
...
Weider, C., and J. Reynolds, "Executive Introduction to Directory
Services Using the X.500 Protocol", FYI 13, RFC 1308fyi13, ANS, ISI,
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... March 1992.
Lang, R., and R. Wright, Editors, "A Catalog of Available X.500
Implementations", FYI 11, RFC 1292(-> 1632(-> 2116fyi11)), SRI International, Lawrence
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... COSINE and Internet
X.500 Schema", RFC 1274prop(-> 4524prop), University College London, November 1991.
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... Replication Requirements to provide an
Internet Directory using X.500", RFC 1275, University College
London, November, 1991.
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... Hardcastle-Kille, S., "Replication and Distributed Operations
extensions to provide an Internet Directory using X.500", RFC
1276hist, University College London, November 1991.
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... 1278, University College London, November 1991.
Hardcastle-Kille, S., "X.500 and Domains", RFC 1279exp, University
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