rfc1431.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

Network Working Group                                          P. Barker
Request for Comments: 1431                     University College London
                                                           February 1993


                              DUA Metrics

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard.  Distribution of this memo is
   unlimited.

Abstract

   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.

   This document defines a set of criteria by which a DUA
   implementation, or more precisely a Directory user interface, may be
   judged.  Particular issues covered include terminal requirements;
   style of interface; target user; default object classes and attribute
   types; use of DAP; error handling.  The focus of the note is on
   "white pages" DUAs: this is a reflection of the current information
   base.  Nevertheless much of the document will be applicable to DUAs
   developed for other types of Directory usage.

   Please send comments to the author or to the discussion group <osi-
   [e-mail]>.

Table of Contents

   1.  Overview................................................       2
   2.  General Information.....................................       3
   3.  Conformance to OSI Standards............................       5
       3.1    Directory protocols..............................       5
       3.2    Protocol stacks..................................       5
       3.3    Schema ..........................................       5
       3.4    DIT structure  ..................................       5
   4.  Conformance to Research Community Standards.............       6
   5.  The General Style of the DUA............................       6
   6.  Schema..................................................       7
       6.1    Object Classes and Attribute Types...............       7
       6.2    DIT structure....................................       8
   7.  Entering queries........................................       9



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   8.  Strategy for locating entries...........................       9
   9.  Displaying results......................................      10
   10. Association Handling....................................      11
   11. Suitability for management..............................      12
   12. Query Resolution........................................      13
   13. International Languages.................................      16
   14. User Friendliness.......................................      16
   15. Operational Use.........................................      17
   16. Security Considerations.................................      19
   17. Author's Address........................................      19

1.  Overview

   The purpose of this document is to define some metrics by which DUA
   products can be measured.  It should be first be noted that the use
   of the term "DUA" is rather misleading.  There is an assumption here
   that the DUA is implemented correctly and is able to "talk" valid
   X.500 protocol: this is a sine qua non.  Instead, this document seeks
   to draw out the characteristics of Directory user interfaces.
   However, the term DUA is persisted with as it is used by most people
   when referring to Directory user interfaces.  The format of these DUA
   metrics is essentially a questionnaire which extracts a detailed
   description of a user interface.  DUAs come in very different forms.
   Many make use of windowing environments, offering a "high-tech" view
   of the Directory, while others are designed to work in a terminal
   environment.  Some interfaces offer extensive control over the
   Directory, and thus may be well-suited to Directory managers, while
   others are aimed more at the novice user.  Some interfaces are
   configurable to allow searches for any attribute in any part of the
   DIT, while others lack this generality but are focussed on handling
   the most typical queries well.  In many aspects, it is almost
   impossible to say that one DUA is better than other from looking at
   the responses to question in this document.  A flexible management
   tool will be better for management than a DUA aimed at servicing
   simple look-ups, and vice-versa.  Furthermore, in other areas, there
   are several radically different approaches to a problem, but it is
   not as yet clear whether one approach is better than another.  One
   example of this is the extent to which a DUA provides an abstraction
   of the underlying DIT hierarchy, either emphasising the world as a
   tree or trying to conceal this from the user.

   However, other aspects, such as whether the DUA can actually find the
   entries required, and if so, how quickly, can be directly measured in
   some way.  Throughout this document, some of the questions posed are
   annotated with a square-bracketed points score and an explanation as
   to how the points should be allocated.  For example, a question might
   be appended with "[2 if yes]", indicating score 2 points for an
   affirmative answer to that question.  These points scores should be



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   collated in Table 1 at the end of the document, and this table
   constitutes a measure of the DUA. The metrics are on a section by
   section basis, which should help the reader who is seeking, for
   example, a DUA with good management capabilities which runs on a wide
   variety of platforms, to focus on the critical aspects of a DUA for
   the particular requirement.

2.  General Information

   This section contains general information about the implementation
   under discussion.

   1.  Name of the implementation ......................................

   2.  Version number of the DUA described in this document ............

   3.  Are further versions planned?  [3 if yes] .......................

   4.  Name and address of supplier or person to contact ...............
    ....................................................................
    ....................................................................
    ....................................................................
    ....................................................................
    ....................................................................
    ....................................................................

   5.  Describe the hardware and software platforms on which the DUA will
       run.  Some DUAs are split into a user interface part, and a DUA
       server part, communicating by means of a protocol.  If the DUA is
       of the type where the DUA protocol machinery and user agent are
       implemented in a single process, complete only the user interface
       section, and indicate "n/a" for the DUA server and
       communications protocol questions.

      (a)  User interface part [1 per platform, up to a maximum of 4]

           i.  Hardware (If appropriate, can summarise as, for example,

          ii.  O/S (state version if critical)

               A.  UNIX (be sure to indicate which flavour - e.g., SYSV,
                   BSD, SUNOS, etc) ....................................
                ........................................................

               B.  VMS) ................................................

               C.  MS-DOS ..............................................




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               D.  MS-Windows ..........................................

               E.  Macintosh ...........................................

               F.  Other) ..............................................

      (b)  DUA server part (or n/a) ....................................

           i.  Hardware (If appropriate, can summarise as, for example,
               "generic UNIX platform", or "386 PC") ...............

          ii.  O/S (state version if critical)

               A.  UNIX (be sure to indicate which flavour - e.g., SYSV,
                   BSD, SUNOS, etc) ....................................

               B.  VMS) ................................................

               C.  MS-DOS ..............................................

               D.  Macintosh ...........................................

               E.  Other) ..............................................

         iii.  How does the user interface communicate with the DUA
               server?

               A.  Directory Assistance Service, as described in RFC1202
                ........................................................

               B.  DIXIE protocol, as described in RFC1249 .............

               C.  LDAP protocol, as described in Internet Draft OSI-DS
                   26

               D.  Other ...............................................

      (c)  Name any other software required to run the DUA which is not
           supplied with the operating system or with the DUA software
           itself.  Examples might include X.500 DAP libraries, or
           communications software .....................................

   6.  Is the software free?  If the DUA needs other packages, are these
       also freely available?  [3 if completely free] ..................
    ....................................................................






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3.  Conformance to OSI Standards

3.1  Directory protocols

   7.  Please list all conformance testing work applied to the DUA
       implementation (here the term DUA is used correctly in the sense
       of the DUA protocol machinery) [2 if any conformance work has been
       done] ...........................................................
    ....................................................................

3.2  Protocol stacks

   For the next two questions, [2 per stack supported for up to 4
   stacks]

   8.  Which of the following transport and network layer protocols does
       the DUA support:

      (a)  TP.x over CONS (state transport class) ......................

      (b)  TP.4 over CLNS ..............................................

   9.  Does the DUA support other transport and "network" layer
       protocols?

      (a)  TP.x over RFC1006 over TCP/IP (state transport class) .......

      (b)  TP.x over X.25(1980) (state transport class) ................

      (c)  State any other options supported.  .........................

   10. Does the DUA also run over any lightweight stack?  If so, describe
       it with reference to the OSI seven layer model [3] ..............
    ....................................................................

3.3  Schema

   11. Does the DUA support the full schema in X.520 and X.521 (y/n)?
       (Omissions should be described in response to a later question) [2
       for full schema support] ........................................

3.4  DIT structure

   12. Does the DUA only follow object class hierarchies which conform to
       the suggested DIT structure in X.521?............................






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4.  Conformance to Research Community Standards

   The COSINE and Internet Directory Pilots have agreed a set of
   extensions to the standard, which make for a more cohesive pilot.
   This section is about conformance to these extensions.

   13. Does the DUA fully support RFC1274, "The COSINE and Internet
       X.500 Schema" (y/n)?  (Omissions should be described in response
       to a later question) [2 for full support] .......................

   14. Can the DUA handle referrals whose network addresses conform to
       RFC1277, "Encoding Network Addresses to support operation over
       non-OSI lower layers"?  [2 if yes] .............................

   15. Does the DUA handle the Distinguished Name string syntax described
       in OSI-DS 23, "A String Representation of Distinguished Names"
       [2 if yes] ......................................................
    ....................................................................

   16. Does the DUA use the user-friendly naming query resolution
       described in OSI-DS 24, "Using the OSI Directory to achieve User
       Friendly Naming" [2 if yes] ....................................

   17. Does the DUA make use of the Quality of Service schema extensions
       described in OSI-DS 15, "Handling QOS (Quality of service) in the
       Directory" [2 if yes] ..........................................

5.  The General Style of the DUA

   18. Is this a "white pages" interface, designed to give access to
       information about people within organisations?  If not, state the
       types of information at which this interface is targetted .......
    ....................................................................

   19. If this is a white pages DUA, who is it principally designed to
       serve?  Indicate more than one of the following categories if
       appropriate (but please do not fill in so may categories as to
       hide due emphasis):  [mark allocated should be the highest for any
       single classification]

      (a)  The ordinary user, who has no understanding of X.500, the
           hierarchical DIT, the state of advancement of the pilot, etc.
           [10] ........................................................

      (b)  A secretary who wants to do telephone or room number look-ups
           within their department or organisation [8] .................

      (c)  A computer-literate user, who habitually uses a wide-range of



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           network services [6] ........................................

      (d)  An organisation's (or department's) data manager [4] ........

      (e)  A Directory system manager [2] ..............................

   20. Which best describes the use the DUA makes of the user's terminal?

      (a)  Scrolling, line-mode interface ..............................

      (b)  Full screen, "vt100" style interface ......................

      (c)  X-Windows ...................................................