Article View: comp.protocols.iso
Article #538SUMMARY: Non-OSI use of ASN.1
From: Philipp Hoschka
Date: Tue, 01 Sep 1992 16:43
Date: Tue, 01 Sep 1992 16:43
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9033 bytes
About a week ago I posted a message asking for any projects that
do not use OSI standards, but make use of ASN.1. The following is
the summary of the responses I got (thank you all again), and some data I
compiled myself from the literature.
In summary, ASN.1 is used in the following non-OSI projects:
- Kerberos (authentication protocol),
- WAIS (information server access protocol),
- ODA/ODIF (document interchange format),
- SNMP (Network management protocol),
- database front-end protocol,
- trading-room industry protocol,
- digital video interchange protocol.
As appendix you find a detailed description for each project.
----------------------------------------------------------------------
Philipp Hoschka | INRIA-Rodeo
hoschka@sophia.inria.fr | 2004, Route des Lucioles, BP 93
Ph: (+33) 93 65 77 47 | 06902 Sophia Antipolis Cedex
Fax:(+33) 93 65 77 66 | France
----------------------------------------------------------------------
DETAILED SUMMARY:
-----------------------------------------------
Name of project: Kerberos version 5
Short description of the project: Kerberos is an authentication protocol to
verify the identity of users, workstations, etc, developed in Project
Athena at MIT.
Documents describing the project:
Kohl, John and Clifford Neumann. "The Kerberos Network Athentication
Service." Internet-Draft. (draft-ietf-cat-kerberos-00.txt)
For what specific purpose is ASN.1 used: to define the PDU's exchanged between
a client and an authentication server or an application server,
respectively. Uses distinguished encoding rules.
Any ASN.1 macros used: None
Which ASN.1 compiler was used: The Athena implementation uses the ISODE tools.
------------------------------------------------------------
Name of project: ODA/ODIF (Open Document Architecture, Open Document
Interchange Format
Short description of the project: ODA is an ISO (but not OSI) standard for
document interchange.
Documents describing the project:
- ISO-8613-1,-2,-4,-5,-6,-7,-8
- Rosenberg, Jonathan, Mark Sherman, Ann Marks and Jaap Akkerhuis.
Multimedia document translation: ODA and the EXPRESS project.
For what specific purpose is ASN.1 used: The ODIF standard (part 5) uses ASN.1
to define the format of the data stream to interchange office documents
structured according to ODA. Standards defining specific content
architectures (characters (part 6), raster graphics (part 7), geometric
graphics (part 8)) also use ASN.1.
Any ASN.1 macros used: None (?)
Which ASN.1 compiler was used: The EXPRESS project used the ISODE tools.
------------------------------------------------------------
Name of the project: SNMP (Simple Network Management Protocol)
Short description of the project: SNMP serves to exchange information between
network management software and managed network devices. It is in
widespread use today.
For what specific purpose is ASN.1 used: ASN.1 is applied for two purposes in
SNMP: Firstly, it is used to define the PDU's of the protocol. Secondly,
it is used to define the structure of the database of objects that can be
queried and changed in a managed network device by using the protocol -
the MIB (Management Information Base).
Documents describing the project:
- "A Simple Network Management Protocol" (incl. PDU's in ASN.1):
RFC 1157
- "Structure and Identification of Management Information for
TCP/IP-based Internets", RFC 1155
- "Management Information Base for Network Management of
TCP/IP-based Internets", RFC 1157
(these are only the base documents - for further MIB-related RFCs,
see your local RFC server ....)
- Rose, Marshal. The simple book. Englewood Cliffs: Prentice Hall,
1991.
Any ASN.1 macros used: OBJECT-TYPE macro defined in RFC 1155
Difficulties experienced when using ASN.1:
or rather simplifications made to ASN.1 (because of difficulties ?):
- only subset of all ASN.1 types may be used in MIB: Integer, Octet String,
Sequence (without optional components), Sequence-of, Object Identifier,
Null
- only two subtyping notations may be used: size-constraints, value-range
constraints
- use of indefinite length form in BER encodings prohibited
Which ASN.1 compiler was used:
- Rose describes use of PEPSY and MOSY (special tool to process
OBJECT-TYPE macro).
- An SNMP implementation that does not use an ASN.1 compiler is
described in:
Comer, Douglas, David Stevens. Internetworking with TCP/IP - Volume
II. Englewood Cliffs: Prentice Hall. 1991
--------------------------------------------------
Information provided by: ses@simon.demon.co.uk
Short description of the project: WAIS is an implementation of NISo Standard
Z39.50 1988, which was developed pre ASN.1. The 1992 version of the
protocol is specified in ASN.1, hence the change. Note that the
profile specified for use on the Internet specifically forbids the use
of the session and presentation layer protocols; raw BER is fed
directly into TCP.
For what specific purpose is ASN.1 used: Protocol and some datatypes. In one
version an ASN.1 interpreter is used to allow recdord types to be defined
on the fly.
Any ASN.1 macros used: None.
Difficulties experienced when using ASN.1:Implementing the interpreter (Why
can't OSI ever decide between competing ideas instead of
mandating them all).
Which ASN.1 compiler was used: Interpreter, actually :-). One version uses
interpreter, other is hand-coded (or will be when I get it finished).
Other implementors of Z39.50 have used ISODE, plus various whacky stuff
on IBM mainframes- Melvyl was done in Pl/1 + assembler, hand coded.
The official IBM product had serious problems with recursive data
types.
---------------------------------------------------
Information provided by: mitra@pandora.sf.ca.us
Sorry I cant answer all your questions, this is a commercial project,
and I am bound by non-disclosure.
Name of project: Pandora database front-end
Short description of the project: Initial phase involves producing a
client-server database access project for specific databases on a
specific host. User's accessing via modem
Documents describing the project: None at present
For what specific purpose is ASN.1 used: Refining and extending Z39.50
to meet specific needs
Any ASN.1 macros used: None so far
Difficulties experienced when using ASN.1: Obtaining documentation,
specifically of ASN.1 itself, current versions of the standard
in machine readable form. Finding a compiler.
Which ASN.1 compiler was used: None yet - have not received replies
to emailed requests for documentation and pricing on compilers.
------------------------------------------------
Information provided by: Paul Andon <pandon@micrognosis.co.uk>
Status: Private project
Name of project: URD
Short description of the project:
Aimed primarily at the trading room industry,
the Universal Record Distribution (URD) protocol
is a connectionless realtime reliable transport
level protocol for transporting variable length
records on a one to many basis.
Documents describing the project: Confidential
For what specific purpose is ASN.1 used:
Unlike most high-performance realtime protocols
nearly all fields in URD were of variable length.
ASN.1 was used primarily as a definition language
with which to define all inter-host and inter-process
URD messages. ALL encodings were done manually in
order to "guarentee" performance. The intention is
to make use of ASN.1 compilers when peformance of
generated code becomes acceptible.
Which ASN.1 compiler was used: none
----------------------------------------------
Information provided by: "David C. Carver" <dcc@Athena.MIT.EDU>
Short desription of the project:
For what specific purpose is ASN.1 used:
I'm currently working in a taskforce in the Society of Motion Picture
and Television Engineers (SMPTE) and we are considering the use of ASN.1
to implement headers and descriptors for digital video interchange.
Technical Details
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Path: arc1-ca.pugleaf.net!sparky!uunet!mcsun!corton!sophia!tom.inria.fr!hoschka From: hoschka@tom.inria.fr (Philipp Hoschka ) Newsgroups: comp.protocols.iso Subject: SUMMARY: Non-OSI use of ASN.1 Keywords: ASN.1, OSI Message-ID: <28320@sophia.inria.fr> Date: 1 Sep 92 16:43:45 GMT References: <1992Aug18.174303.2087@nosc.mil> <23310A@erik.naggum.no> <EICHIN.92Aug19032948@tsx-11.mit.edu> <27433@sophia.inria.fr> Sender: news@sophia.inria.fr Organization: INRIA Lines: 202