Textual Conventions for the Representation of Floating-Point Numbers
RFC 6340

Internet Engineering Task Force (IETF)                        R. Presuhn
Request for Comments: 6340                                   Independent
Category: Standards Track                                    August 2011
ISSN: 2070-1721

  Textual Conventions for the Representation of Floating-Point Numbers

Abstract

   This memo defines a Management Information Base (MIB) module
   containing textual conventions (TCs) to represent floating-point
   numbers.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6340.

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   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Presuhn                      Standards Track                    [Page 1]
RFC 6340           Floating-Point Textual Conventions        August 2011

Table of Contents

   1. Introduction ....................................................2
   2. The Internet-Standard Management Framework ......................3
   3. Applicability ...................................................3
   4. Structure of the MIB Module .....................................4
      4.1. MIB Modules Required for IMPORTS ...........................4
      4.2. Documents Required for REFERENCE Clauses ...................4
   5. Definitions .....................................................4
   6. Security Considerations .........................................6
   7. IANA Considerations .............................................6
   8. Contributors ....................................................6
   9. References ......................................................7
      9.1. Normative References .......................................7
      9.2. Informative References .....................................7

1.  Introduction

   This memo defines textual conventions for the representation of
   floating-point numbers.  All of these definitions are in terms of the
   IEEE "Standard for Floating-Point Arithmetic", IEEE 754-2008
   [IEEE.754.2008].

   The IEEE "Standard for Floating-Point Arithmetic", IEEE 754-2008
   [IEEE.754.2008], provides for a variety of interchange formats for
   floating-point numbers.  The need for three of these, namely

   o  32-bit,

   o  64-bit,

   o  128-bit,

   has been recognized in network management.  For example, Section
   4.2.3 of the SMIng Objectives [RFC3216] elaborates the need for these
   three floating-point data types in network management protocols.

   The selection of a floating-point format involves many considerations
   and trade-offs.  For an introduction to the fundamentals of floating-
   point representations see Chapter 4 of [KNUTH]; for a discussion of
   these issues specifically with respect to the IEEE formats, see
   [GOLDBERG].

   All of these textual conventions employ the binary interchange format
   defined in [IEEE.754.2008].  Specifically, this means that for all of
   them, the highest-order bit of the first byte is the sign bit, with
   the remaining bits of the octet string corresponding to the exponent
   and fraction parts, in network byte order.

Presuhn                      Standards Track                    [Page 2]
RFC 6340           Floating-Point Textual Conventions        August 2011

2.  The Internet-Standard Management Framework

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to section 7 of
   RFC 3410 [RFC3410].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  MIB objects are generally
   accessed through the Simple Network Management Protocol (SNMP).