Juergen Schoenwaelder
Internet-Draft                                           TU Braunschweig
Expires May 1999                                        18 November 1998


                    Textual Conventions Extension 1

                   <draft-schoenw-snmp-tc-ext-00.txt>

Status of this Memo

   This document is an Internet-Draft. Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas,
   and its working groups.  Note that other groups may also distribute
   working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as ``work in progress.''

   To view the entire list of current Internet-Drafts, please check the
   "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow
   Directories on ftp.is.co.za (Africa), ftp.nordu.net (Northern
   Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific
   Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast).

   Distribution of this document is unlimited. Please send comments to
   the SNMP Version 3 Working Group, <snmpv3@tis.com>.

Abstract

   This memo defines new textual conventions that are considered to be
   generally useful. This memo extends the set of textual conventions
   defined in RFC 1903, which also defines the language used to define
   textual conventions.















J. Schoenwaelder                                                [Page 1]


Internet-Draft           System MIB Extensions             November 1998


   Table of Contents

   1 Introduction .................................................    2
   2 Definitions ..................................................    2
   3 Acknowledgments ..............................................    5
   4 Authors' Address .............................................    5


1.  Introduction

   This memo defines new textual conventions that are considered to be
   generally useful. It extends the set of textual conventions defined
   in RFC 1903. For more information about textual conventions, please
   consult RFC 1903.


2.  Definitions

   SNMPv2-TC-EXT-01 DEFINITIONS ::= BEGIN

   IMPORTS
       MODULE-IDENTITY
           FROM SNMPv2-SMI
       TEXTUAL-CONVENTION
           FROM SNMPv2-TC;

   -- This module is not valid SMIv2. The author left out all the
   -- administrative stuff in order to keep it small.

   InternationalString ::= TEXTUAL-CONVENTION
       DISPLAY-HINT "255t"
       STATUS       current
       DESCRIPTION
           "An octet string containing human-readable information.

            To facilitate internationalization, this information is
            represented using the ISO/IEC IS 10646-1 character set,
            encoded as an octet string using the UTF-8 transformation
            format described in [RFC2279].

            Since additional code points are added by amendments to the
            10646 standard from time to time, implementations must be
            prepared to encounter any code point from 0x00000000 to
            0x7fffffff.  Byte sequences that do not correspond to the
            valid UTF-8 encoding of a code point or are outside this
            range are prohibited.





J. Schoenwaelder                                                [Page 2]


Internet-Draft           System MIB Extensions             November 1998


            The use of control codes should be avoided. When it is
            necessary to represent a newline, the control code sequence
            CR LF should be used.

            For code points not directly supported by user interface
            hardware or software, an alternative means of entry and
            display, such as hexadecimal, may be provided.

            For information encoded in 7-bit US-ASCII, the UTF-8 encoding
            is identical to the US-ASCII encoding.

            UTF-8 may require multiple bytes to represent a single
            character / code point; thus the length of this object in
            octets may be different from the number of characters
            encoded.  Similarly, size constraints refer to the number of
            encoded octets, not the number of characters represented by
            an encoding.

            Note that when this TC is used for an object that is used or
            envisioned to be used as an index, then a SIZE restriction
            MUST be specified so that the number of sub-identifiers for
            any object instance does not exceed the limit of 128, as
            defined by [RFC1905].

            Note that the size of an InternationalString object is
            measured in octets, not characters."
       SYNTAX      OCTET STRING (SIZE (0..255))

   TAddressOrZero ::= TEXTUAL-CONVENTION
       STATUS      current
       DESCRIPTION
           "Denotes a transport service address. A zero-length octet
            string indicates that no transport address is known.

            A TAddress value is always interpreted within the context of
            a TDomain value.  Thus, each definition of a TDomain value
            must be accompanied by a definition of a textual convention
            for use with that TDomain.  Some possible textual conventions,
            such as SnmpUDPAddress for snmpUDPDomain, are defined in the
            SNMPv2-TM MIB module.  Other possible textual conventions are
            defined in other MIB modules.

            Note, the definition of this textual convention is identical
            to the TAddress definition in the SNMPv2-TM MIB module with
            the only difference that this textual convention allows a
            zero-length TAddress value."
       SYNTAX      OCTET STRING (SIZE (0..255))





J. Schoenwaelder                                                [Page 3]


Internet-Draft           System MIB Extensions             November 1998


   TAddressMask ::=
       STATUS      current
       DESCRIPTION
           "Denotes a transport service address mask.

            A mask value is used to select which bits of a transport
            address must match bits of the corresponding instance of
            a TAddress object. The value of an instance of this textual
            convention must always be an OCTET STRING whose length is
            either zero or the same as that of the corresponding instance
            of a TAddress object.

            The matching algorithm is as follows:

            Each bit of each octet in the TAddressMask value corresponds
            to the same bit of the same octet in the TAddress value. For
            bits that are set in the TAddressMask value (i.e. bits equal
            to 1), the corresponding bits in the TAddress value must
            match the bits in a given transport address. If all such bits
            match, the transport address is matched. Otherwise, the match
            fails."
       SYNTAX      OCTET STRING (SIZE (1..255))

   TAddressMaskOrZero ::=
       STATUS
       DESCRIPTION
           "Denotes a transport service address mask. A zero-length octet
            string indicates that the match always succeeds.

            A mask value is used to select which bits of a transport
            address must match bits of the corresponding instance of
            a TAddress object. The value of an instance of this textual
            convention must always be an OCTET STRING whose length is
            either zero or the same as that of the corresponding instance
            of a TAddress object.

            The matching algorithm is as follows:

            If the value of the TAddressMask is a zero-length OCTET
            STRING, the mask value is ignored and the match succeeds.

            Otherwise, each bit of each octet in the TAddressMask value
            corresponds to the same bit of the same octet in the
            TAddress value. For bits that are set in the TAddressMask
            value (i.e. bits equal to 1), the corresponding bits in the
            TAddress value must match the bits in a given transport
            address. If all such bits match, the transport address is





J. Schoenwaelder                                                [Page 4]


Internet-Draft           System MIB Extensions             November 1998


            matched. Otherwise, the match fails."
       SYNTAX      OCTET STRING (SIZE (0..255))
   END


3.  Acknowledgments

   The definitions in this memo are inspired by definitions found in
   other RFCs and Internet-Drafts. Most of the text in the descriptions
   is therefore copied from other sources. Special thanks go to David
   Levi, Randy Presuhn and Keith McCloghrie for writing the original
   descriptions.


4.  Authors' Address

     Juergen Schoenwaelder             Email: schoenw@ibr.cs.tu-bs.de
     TU Braunschweig                     Tel: +49 531 391-3283
     Bueltenweg 74/75
     38106 Braunschweig
     Germany






























J. Schoenwaelder                                                [Page 5]

Internet-Draft           System MIB Extensions             November 1998