On the Difference between Information Models and Data Models
RFC 3444
Document | Type |
RFC - Informational
(January 2003; No errata)
Was draft-irtf-nmrg-im-dm (individual in ops area)
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Authors | Aiko Pras , Jürgen Schönwälder | ||
Last updated | 2015-10-14 | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 3444 (Informational) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Bert Wijnen | ||
IESG note | Published as RFC 3444 | ||
Send notices to | (None) |
Network Working Group A. Pras Request for Comments: 3444 University of Twente Category: Informational J. Schoenwaelder University of Osnabrueck January 2003 On the Difference between Information Models and Data Models 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 Internet Society (2003). All Rights Reserved. Abstract There has been ongoing confusion about the differences between Information Models and Data Models for defining managed objects in network management. This document explains the differences between these terms by analyzing how existing network management model specifications (from the IETF and other bodies such as the International Telecommunication Union (ITU) or the Distributed Management Task Force (DMTF)) fit into the universe of Information Models and Data Models. This memo documents the main results of the 8th workshop of the Network Management Research Group (NMRG) of the Internet Research Task Force (IRTF) hosted by the University of Texas at Austin. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Information Models . . . . . . . . . . . . . . . . . . . . . . 3 4. Data Models . . . . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6 7. Normative References . . . . . . . . . . . . . . . . . . . . . 6 8. Informative References . . . . . . . . . . . . . . . . . . . . 7 9. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 7 10. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 8 Pras & Schoenwaelder Informational [Page 1] RFC 3444 Information Models and Data Models January 2003 1. Introduction Currently multiple languages exist to define managed objects. Examples of such languages are the Structure of Management Information (SMI) [1], the Structure of Policy Provisioning Information (SPPI) [2] and, within the DMTF, the Managed Object Format (MOF) [3]. Despite the fact that multiple languages exist, a number of people still believe that none of these languages really suits all needs. There have been many discussions to understand the advantages and disadvantages, as well as the main differences, between various languages. For instance, the IETF organized a BoF on "Network Information Modeling" (NIM) at its 48th meeting (Pittsburgh, August 2000). During these discussions, it turned out that people had a different understanding of the main terms, which caused confusion and long arguments. In particular, the meaning of the terms "Information Model" (IM) and "Data Model" (DM) turned out to be controversial. In an attempt to address this issue, the IRTF Network Management Research Group (NMRG) dedicated its 8th workshop (Austin, December 2000) to harmonizing the terminology used in information and data modeling. Attendees included experts from the IETF, DMTF and ITU, as well as academics who do research in this field (see the Acknowledgments section for a list of participants). The main outcome of this successful workshop -- a better understanding of the terms "Information Model" and "Data Model" -- is presented in this document. Short definitions of these terms can also be found elsewhere (e.g., in RFC 3198 [8]). Compared to most other documents, this one explains the rationale behind the proposed definitions and provides examples. 2. Overview One of the key observations made at the NMRG workshop was that IMs and DMs are different because they serve different purposes. The main purpose of an IM is to model managed objects at a conceptual level, independent of any specific implementations or protocols used to transport the data. The degree of specificity (or detail) of the abstractions defined in the IM depends on the modeling needs of its designers. In order to make the overall design as clear as possible, an IM should hide all protocol and implementation details. Another important characteristic of an IM is that it defines relationships between managed objects. Pras & Schoenwaelder Informational [Page 2] RFC 3444 Information Models and Data Models January 2003 DMs, conversely, are defined at a lower level of abstraction andShow full document text