Network Working Group F. Strauss Internet-Draft J. Schoenwaelder Expires: May 25, 2001 TU Braunschweig K. McCloghrie Cisco Systems November 24, 2000 SMIng Core Modules draft-irtf-nmrg-sming-modules-01 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on May 25, 2001. Abstract This memo presents an SMIng module that introduces core data types such as counters, date and time related types, and various string types. These definitions build on RFC 2578 and RFC 2579. Copyright Notice Copyright (C) The Internet Society (2000). All Rights Reserved. Strauss, et. al. Expires May 25, 2001 [Page 1] Internet-Draft SMIng Modules November 2000 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. IRTF-NMRG-SMING . . . . . . . . . . . . . . . . . . . . . . . 3 3. Security Considerations . . . . . . . . . . . . . . . . . . . 11 4. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11 References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 12 A. OPEN ISSUES . . . . . . . . . . . . . . . . . . . . . . . . . 13 Strauss, et. al. Expires May 25, 2001 [Page 2] Internet-Draft SMIng Modules November 2000 1. Introduction SMIng [1] modules are built on top of some core definitions. These core definitions are imported from some "well-defined" core modules described in this memo. The IRTF-NMRG-SMING module defines a set of common SMIng data types. These data types are generally applicable for modelling all areas of management information. Among these types are counter types, string types and date and time related types. This module is derived from RFC 2578 [3] and [4]. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [2]. 2. IRTF-NMRG-SMING module IRTF-NMRG-SMING { organization "IRTF Network Management Research Group (NMRG)"; contact "Frank Strauss TU Braunschweig Bueltenweg 74/75 38106 Braunschweig Germany Phone: +49 531 391-3266 EMail: strauss@ibr.cs.tu-bs.de"; description "Core type definitions for SMIng. Several type definitions are SMIng versions of similar SMIv2 or SPPI definitions."; revision { date "2000-11-23"; description "Initial revision, published as RFC XXXX."; }; typedef Gauge32 { type Unsigned32; description "The Gauge32 type represents a non-negative integer, which may increase or decrease, but shall never exceed a maximum value, nor fall below a minimum value. The maximum value can not be greater than 2^32-1 (4294967295 decimal), and the minimum value Strauss, et. al. Expires May 25, 2001 [Page 3] Internet-Draft SMIng Modules November 2000 can not be smaller than 0. The value of a Gauge32 has its maximum value whenever the information being modeled is greater than or equal to its maximum value, and has its minimum value whenever the information being modeled is smaller than or equal to its minimum value. If the information being modeled subsequently decreases below (increases above) the maximum (minimum) value, the Gauge32 also decreases (increases). (Note that despite of the use of the term `latched' in the original definition of this type, it does not become `stuck' at its maximum or minimum value.)"; reference "RFC 2578, Sections 2. and 7.1.7."; }; typedef Counter32 { type Unsigned32; description "The Counter32 type represents a non-negative integer which monotonically increases until it reaches a maximum value of 2^32-1 (4294967295 decimal), when it wraps around and starts increasing again from zero. Counters have no defined `initial' value, and thus, a single value of a Counter has (in general) no information content. Discontinuities in the monotonically increasing value normally occur at re-initialization of the management system, and at other times as specified in the description of an attribute using this type. If such other times can occur, for example, the creation of a class instance that contains an attribute of type Counter32 at times other than re-initialization, then a corresponding attribute should be defined, with an appropriate type, to indicate the last discontinuity. Examples of appropriate types include: TimeStamp, DateAndTime or TimeTicks (other types defined in this module). The value of the access statement for attributes with a type value of Counter32 should be either `readonly' or `eventonly'. A default statement should not be used for attributes with a type value of Counter32."; reference "RFC 2578, Sections 2. and 7.1.6."; }; Strauss, et. al. Expires May 25, 2001 [Page 4] Internet-Draft SMIng Modules November 2000 typedef Gauge64 { type Unsigned64; description "The Gauge64 type represents a non-negative integer, which may increase or decrease, but shall never exceed a maximum value, nor fall below a minimum value. The maximum value can not be greater than 2^64-1 (18446744073709551615), and the minimum value can not be smaller than 0. The value of a Gauge64 has its maximum value whenever the information being modeled is greater than or equal to its maximum value, and has its minimum value whenever the information being modeled is smaller than or equal to its minimum value. If the information being modeled subsequently decreases below (increases above) the maximum (minimum) value, the Gauge64 also decreases (increases). (Note that despite of the use of the term `latched' in the original definition of this type, it does not become `stuck' at its maximum or minimum value.)"; }; typedef Counter64 { type Unsigned64; description "The Counter64 type represents a non-negative integer which monotonically increases until it reaches a maximum value of 2^64-1 (18446744073709551615), when it wraps around and starts increasing again from zero. Counters have no defined `initial' value, and thus, a single value of a Counter has (in general) no information content. Discontinuities in the monotonically increasing value normally occur at re-initialization of the management system, and at other times as specified in the description of an attribute using this type. If such other times can occur, for example, the creation of a class instance that contains an attribute of type Counter32 at times other than re-initialization, then a corresponding attribute should be defined, with an appropriate type, to indicate the last discontinuity. Examples of appropriate types include: TimeStamp, DateAndTime or TimeTicks (other types defined in this module). The value of the access statement for attributes with a type value of Counter64 should be either `readonly' or `eventonly'. Strauss, et. al. Expires May 25, 2001 [Page 5] Internet-Draft SMIng Modules November 2000 A default statement should not be used for attributes with a type value of Counter64."; reference "RFC 2578, Sections 2. and 7.1.10."; }; typedef Opaque { type OctetString; status obsolete; description "******* THIS TYPE DEFINITION IS OBSOLETE ******* The Opaque type is provided solely for backward-compatibility, and shall not be used for newly-defined attributes and derived types. The Opaque type supports the capability to pass arbitrary ASN.1 syntax. A value is encoded using the ASN.1 Basic Encoding Rules into a string of octets. This, in turn, is encoded as an OctetString, in effect `double-wrapping' the original ASN.1 value. Note that a conforming implementation need only be able to accept and recognize opaquely-encoded data. It need not be able to unwrap the data and then interpret its contents. A requirement on `standard' modules is that no attribute may have a type value of Opaque and no type may be derived from the Opaque type."; reference "RFC 2578, Sections 2. and 7.1.9."; }; typedef IpAddress { type OctetString (4); status deprecated; description "******* THIS TYPE DEFINITION IS DEPRECATED ******* The IpAddress type represents a 32-bit internet IPv4 address. It is represented as an OctetString of length 4, in network byte-order. Note that the IpAddress type is present for historical reasons. IPv4 and IPv6 addresses should be represented using the InetNetworkEndpoint class defined in the IRTF-NMRG-INET module."; Strauss, et. al. Expires May 25, 2001 [Page 6] Internet-Draft SMIng Modules November 2000 reference "RFC 2578, Sections 2. and 7.1.5."; }; typedef TimeTicks { type Unsigned32; description "The TimeTicks type represents a non-negative integer which represents the time, modulo 2^32 (4294967296 decimal), in hundredths of a second between two epochs. When attributes are defined which use this type, the description of the attribute identifies both of the reference epochs. For example, the TimeStamp type (defined in this module) is based on the TimeTicks type."; reference "RFC 2578, Sections 2. and 7.1.8."; }; typedef TimeStamp { type TimeTicks; description "The value of the sysUpTime attribute at which a specific occurrence happened. The specific occurrence must be defined in the description of any attribute defined using this type. When the specific occurrence occurred prior to the last time sysUpTime was zero, then the TimeStamp value is zero. Note that this requires all TimeStamp values to be reset to zero when the value of sysUpTime reaches 497+ days and wraps around to zero."; reference "RFC 2579, Section 2."; }; typedef TimeInterval { type Integer32 (0..2147483647); description "A period of time, measured in units of 0.01 seconds. The TimeInterval type uses Integer32 rather than Unsigned32 for compatibility with RFC 2579."; reference "RFC 2579, Section 2."; }; typedef DateAndTime { type OctetString (8 | 11); default 0x0000000000000000000000; Strauss, et. al. Expires May 25, 2001 [Page 7] Internet-Draft SMIng Modules November 2000 format "2d-1d-1d,1d:1d:1d.1d,1a1d:1d"; description "A date-time specification. field octets contents range ----- ------ -------- ----- 1 1-2 year* 0..65536 2 3 month 1..12 3 4 day 1..31 4 5 hour 0..23 5 6 minutes 0..59 6 7 seconds 0..60 (use 60 for leap-second) 7 8 deci-seconds 0..9 8 9 direction from UTC '+' / '-' 9 10 hours from UTC* 0..13 10 11 minutes from UTC 0..59 * Notes: - the value of year is in big-endian encoding - daylight saving time in New Zealand is +13 For example, Tuesday May 26, 1992 at 1:30:15 PM EDT would be displayed as: 1992-5-26,13:30:15.0,-4:0 Note that if only local time is known, then timezone information (fields 8-10) is not present. The two special values of 8 or 11 zero bytes denote an unknown date-time specification."; reference "RFC 2579, Section 2."; }; typedef TruthValue { type Enumeration (true(1), false(2)); description "Represents a boolean value."; reference "RFC 2579, Section 2."; }; typedef PhysAddress { type OctetString; format "1x:"; description "Represents media- or physical-level addresses."; Strauss, et. al. Expires May 25, 2001 [Page 8] Internet-Draft SMIng Modules November 2000 reference "RFC 2579, Section 2."; }; typedef MacAddress { type OctetString (6); format "1x:"; description "Represents an IEEE 802 MAC address represented in the `canonical' order defined by IEEE 802.1a, i.e., as if it were transmitted least significant bit first, even though 802.5 (in contrast to other 802.x protocols) requires MAC addresses to be transmitted most significant bit first."; reference "RFC 2579, Section 2."; }; // The DisplayString definition below does not impose a size // restriction and is thus not the same as the DisplayString // definition in RFC 2579. The DisplayString255 definition is // provided for mapping purposes. typedef DisplayString { type OctetString; format "1a"; description "Represents textual information taken from the NVT ASCII character set, as defined in pages 4, 10-11 of RFC 854. To summarize RFC 854, the NVT ASCII repertoire specifies: - the use of character codes 0-127 (decimal) - the graphics characters (32-126) are interpreted as US ASCII - NUL, LF, CR, BEL, BS, HT, VT and FF have the special meanings specified in RFC 854 - the other 25 codes have no standard interpretation - the sequence 'CR LF' means newline - the sequence 'CR NUL' means carriage-return - an 'LF' not preceded by a 'CR' means moving to the same column on the next line. - the sequence 'CR x' for any x other than LF or NUL is Strauss, et. al. Expires May 25, 2001 [Page 9] Internet-Draft SMIng Modules November 2000 illegal. (Note that this also means that a string may end with either 'CR LF' or 'CR NUL', but not with CR.) "; }; typedef DisplayString255 { type DisplayString (0..255); description "A DisplayString with a maximum length of 255 characters. Any attribute defined using this syntax may not exceed 255 characters in length. The DisplayString255 type has the same semantics as the DisplayString textual convention defined in RFC 2579."; reference "RFC 2579, Section 2."; }; // The Utf8String and Utf8String255 definitions below facilitate // internationalization. The definition is consistent with the // definition of SnmpAdminString in RFC 2571. typedef Utf8String { type OctetString; format "65535t"; // is there a better way ? description "A human readable string represented using the ISO/IEC IS 10646-1 character set, encoded as an octet string using the UTF-8 transformation format described in RFC 2279. 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. 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. The use of leading or trailing white space should be avoided. 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 Strauss, et. al. Expires May 25, 2001 [Page 10] Internet-Draft SMIng Modules November 2000 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 a Utf8String 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 the size of an Utf8String is measured in octets, not characters."; }; typedef Utf8String255 { type Utf8String (0..255); format "255t"; description "A Utf8String with a maximum length of 255 octets. Note that the size of an Utf8String is measured in octets, not characters."; }; identity null { description "An identity used to represent null pointer values."; }; }; 3. Security Considerations This module does not define any management objects. Instead, it defines a set of SMIng types and classes which may be used by other SMIng modules to define management objects. These data definitions have no security impact on the Internet. 4. Acknowledgments This document was produced by the Network Management Research Group (NMRG) of the Internet Research Task Force (IRTF). Some definitions in this document are derived from RFC 2578 [3] and RFC 2579 [4], which were written by K. McCloghrie, D. Perkins, J. Schoenwaelder, J. Case, M. Rose, and S. Waldbusser. References Strauss, et. al. Expires May 25, 2001 [Page 11] Internet-Draft SMIng Modules November 2000 [1] Strauss, F., Schoenwaelder, J., McCloghrie, K., "SMIng - Next Generation Structure of Management Information", draft-irtf-nmrg-sming-04.txt, November 2000. [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, BCP 14, March 1997. [3] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., Waldbusser, S., "Structure of Management Information Version 2 (SMIv2)", RFC 2578, STD 59, April 1999. [4] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., Waldbusser, S., "Textual Conventions for SMIv2", RFC 2579, STD 59, April 1999. Authors' Addresses Frank Strauss TU Braunschweig Bueltenweg 74/75 38106 Braunschweig Germany Phone: +49 531 391-3266 EMail: strauss@ibr.cs.tu-bs.de URI: http://www.ibr.cs.tu-bs.de/ Juergen Schoenwaelder TU Braunschweig Bueltenweg 74/75 38106 Braunschweig Germany Phone: +49 531 391-3289 EMail: schoenw@ibr.cs.tu-bs.de URI: http://www.ibr.cs.tu-bs.de/ Keith McCloghrie Cisco Systems 170 West Tasman Drive San Jose, CA 95134-1706 USA Phone: +1 408 526 5260 EMail: kzm@cisco.com URI: http://www.cisco.com/ Strauss, et. al. Expires May 25, 2001 [Page 12] Internet-Draft SMIng Modules November 2000 Appendix A. OPEN ISSUES 1. There might be more core type or class definitions that should go into the IRTF-NMRG-SMING module. Things that come to mind are types for Roles and RoleCombinations or types for Tags and TagLists. 2. Should the current module be split into several smaller modules each focussing on a specific aspect (e.g. strings, data and time, ...)? 3. The description of the TimeStamp type builds on sysUpTime. 4. Define TimeInterval based on Unsigned32 and remove the last sentence from the description? Strauss, et. al. Expires May 25, 2001 [Page 13] Internet-Draft SMIng Modules November 2000 Full Copyright Statement Copyright (C) The Internet Society (2000). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implmentation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Strauss, et. al. Expires May 25, 2001 [Page 14]