Internet Draft Andy Bierman Cisco Systems, Inc. Keith McCloghrie Cisco Systems, Inc. Randy Presuhn BMC Software, Inc. 27 December 1999 Textual Conventions for Additional High Capacity Data Types Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [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. Distribution of this document is unlimited. Please send comments to the authors. 1. Copyright Notice Copyright (C) The Internet Society (1999). All Rights Reserved. Internet-Draft High Capacity Data Types December 1999 2. Abstract This memo specifies new textual conventions for the purpose of providing a broader range of data types for high capacity numbers. 3. Table of Contents 1 Copyright Notice ................................................ 1 2 Abstract ........................................................ 2 3 Table of Contents ............................................... 2 4 The SNMP Management Framework ................................... 2 5 Overview ........................................................ 3 5.1 Short Term and Long Term Objectives ........................... 3 5.2 Limitations of the Textual Convention Approach ................ 4 6 New Textual Conventions ......................................... 6 6.1 CounterBasedGauge64 ........................................... 6 6.2 ZeroBasedCounter64 ............................................ 6 7 Definitions ..................................................... 6 8 Intellectual Property ........................................... 10 9 References ...................................................... 10 10 Security Considerations ........................................ 13 11 Authors' Addresses ............................................. 14 12 Full Copyright Statement ....................................... 15 4. The SNMP Management Framework The SNMP Management Framework presently consists of five major components: o An overall architecture, described in RFC 2571 [RFC2571]. o Mechanisms for describing and naming objects and events for the purpose of management. The first version of this Structure of Management Information (SMI) is called SMIv1 and described in RFC 1155 [RFC1155], RFC 1212 [RFC1212] and RFC 1215 [RFC1215]. The second version, called SMIv2, is described in RFC 2578 [RFC2578], RFC 2579 [RFC2579] and RFC 2580 [RFC2580]. o Message protocols for transferring management information. The first version of the SNMP message protocol is called SNMPv1 and described in RFC 1157 [RFC1157]. A second version of the SNMP message protocol, which is not an Internet standards track protocol, is called SNMPv2c and described in RFC 1901 [RFC1901] and RFC 1906 [RFC1906]. The third version of the message protocol is called SNMPv3 and described in RFC 1906 [RFC1906], Expires June 2000 [Page 2] Internet-Draft High Capacity Data Types December 1999 RFC 2572 [RFC2572] and RFC 2574 [RFC2574]. o Protocol operations for accessing management information. The first set of protocol operations and associated PDU formats is described in RFC 1157 [RFC1157]. A second set of protocol operations and associated PDU formats is described in RFC 1905 [RFC1905]. o A set of fundamental applications described in RFC 2573 [RFC2573] and the view-based access control mechanism described in RFC 2575 [RFC2575]. A more detailed introduction to the current SNMP Management Framework can be found in RFC 2570 [RFC2570]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the mechanisms defined in the SMI. This memo specifies a MIB module that is compliant to the SMIv2. A MIB conforming to the SMIv1 can be produced through the appropriate translations. The resulting translated MIB must be semantically equivalent, except where objects or events are omitted because no translation is possible (use of Counter64). Some machine readable information in SMIv2 will be converted into textual descriptions in SMIv1 during the translation process. However, this loss of machine readable information is not considered to change the semantics of the MIB. 5. Overview The Structure of Management Information [SMIv2] does not explicitly address the question of how to represent integer objects other than counters that would require up to 64 bits to provide the necessary range and precision. There are standards MIBs in progress, such as the RMON MIB for High Capacity Networks [HC-RMON], which need such data types. This memo specifies textual conventions to meet these needs. 5.1. Short Term and Long Term Objectives In order to support Gigabit Ethernet and other high speed interfaces properly, new 'Gauge64' and 'Integer64' data types are needed. There is an immediate need to provide a Gauge64 data type, similar in semantics to the Gauge32 data type, in order to support common data Expires June 2000 [Page 3] Internet-Draft High Capacity Data Types December 1999 representations such as: - a snapshot of a Counter64 at a given moment, e.g., history ring buffer - the difference between 2 Counter64 values Signed integers can be stored in two MIB objects (sign and absolute value) as is done with the usrHistoryTable in the RMON-2 MIB [RFC2021], so there is not an immediate need for an Integer64 data type. This document does not suggest a short-term solution for signed 64-bit integers. In order to be backward compatible with existing implementations of Counter64, the ASN.1 encoding of unsigned 64-bit data types must be identical to the encoding of Counter64 objects, i.e., identified by the [APPLICATION 6] ASN.1 tag. The textual conventions defined in this document represent a limited and short-term solution to the problem. The SMIv2 will not be changed to accomodate this approach, and these textual conventions will be deprecated as a long term solution is defined and deployed to replace them. 5.2. Limitations of the Textual Convention Approach New unsigned data types with textual conventions based on the Counter64 tag, instead of a new (or other existing) ASN.1 tag has some limitations: - The MAX-ACCESS of the TC must be read-only, because the MAX-ACCESS of the underlying Counter64 type is read-only, (as established in RFC 2578 clause 7.1.10 [RFC2578]). - No sub-range can be specified on the TC-derived types, because sub- ranges are not allowed on Counter64 objects. - No DEFVAL clause can be specified for the TC-derived types, because DEFVALs are not allowed on read-only objects. - The TC-derived types cannot be used in an INDEX clause. This is not an important feature, and supporting it would have a significant impact on MIB compliers. Expires June 2000 [Page 4] Internet-Draft High Capacity Data Types December 1999 - Enumerated integers cannot be defined with a value larger than 2147483647. This is not an important feature, and supporting it would have a significant impact on MIB compliers. Expires June 2000 [Page 5] Internet-Draft High Capacity Data Types December 1999 6. New Textual Conventions The following textual conventions are defined to support unsigned 64-bit data types for HC-RMON. 6.1. CounterBasedGauge64 This textual convention defines a 64-bit gauge, but defined with Counter64 syntax, since no Gauge64 base type is available. This TC is used for storing the difference between 2 Counter64 values, or simply storing a snapshot of a Counter64 value at a given moment in time. 6.2. ZeroBasedCounter64 This textual convention defines a 64-bit counter with an initial value of zero, instead of an arbitrary initial value. This TC is used for counter objects in tables which are instantiated by management application action. 7. Definitions SMIv2-HCNUM-TC DEFINITIONS ::= BEGIN IMPORTS MODULE-IDENTITY, experimental, Counter64 FROM SNMPv2-SMI TEXTUAL-CONVENTION FROM SNMPv2-TC; hcnumTC MODULE-IDENTITY LAST-UPDATED "9912260000Z" ORGANIZATION "IETF OPS Area" CONTACT-INFO " E-mail: ops-area@ops.ietf.org Subscribe: majordomo@psg.com w/ msg body: subscribe ops-area Andy Bierman Cisco Systems Inc. 170 West Tasman Drive San Jose, CA 95134 +1 408-527-3711 abierman@cisco.com Expires June 2000 [Page 6] Internet-Draft High Capacity Data Types December 1999 Keith McCloghrie Cisco Systems Inc. 170 West Tasman Drive San Jose, CA 95134 +1 408-526-5260 kzm@cisco.com Randy Presuhn BMC Software, Inc. Office 1-3141 2141 North First Street San Jose, California 95131 USA +1 408 546-1006 rpresuhn@bmc.com" DESCRIPTION "A MIB module containing textual conventions for high capacity data types." REVISION "9912260000Z" DESCRIPTION "Initial Version of the High Capacity Numbers MIB module. This version published as RFC xxxx (to be assigned by the RFC Editor)." ::= { experimental xxx } CounterBasedGauge64 ::= TEXTUAL-CONVENTION STATUS current DESCRIPTION "The CounterBasedGauge64 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 decimal), and the minimum value can not be smaller than 0. The value of a CounterBasedGauge64 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 CounterBasedGauge64 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.) Note that this TC is not strictly legal in SMIv2, because Expires June 2000 [Page 7] Internet-Draft High Capacity Data Types December 1999 the 'always increasing' and 'counter wrap' semantics associated with the Counter64 base type are not preserved. It is possible that management applications which rely solely upon the (Counter64) ASN.1 tag to determine object semantics will mistakenly operate upon objects of this type as they would for Counter64 objects. This textual convention represents a limited and short-term solution, and will be deprecated as a long term solution is defined and deployed to replace it." SYNTAX Counter64 ZeroBasedCounter64 ::= TEXTUAL-CONVENTION STATUS current DESCRIPTION "This TC describes an object which counts events with the following semantics: objects of this type will be set to zero(0) on creation and will thereafter count appropriate events, wrapping back to zero(0) when the value 2^64 is reached. Provided that an application discovers the new object within the minimum time to wrap it can use the initial value as a delta since it last polled the table of which this object is part. It is important for a management station to be aware of this minimum time and the actual time between polls, and to discard data if the actual time is too long or there is no defined minimum time. Typically this TC is used in tables where the INDEX space is constantly changing and/or the TimeFilter mechanism is in use. Note that this textual convention does not retain all the semantics of the Counter64 base type. Specifically, a Counter64 has an arbitrary initial value, but objects defined with this TC are required to start at the value zero. This behavior is not likely to have any adverse effects on management applications which are expecting Counter64 semantics. This textual convention represents a limited and short-term solution, and will be deprecated as a long term solution is defined and deployed to replace it." Expires June 2000 [Page 8] Internet-Draft High Capacity Data Types December 1999 SYNTAX Counter64 END Expires June 2000 [Page 9] Internet-Draft High Capacity Data Types December 1999 8. Intellectual Property The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards- related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. 9. References [HC-RMON] Waldbusser, S., "Remote Network Monitoring Management Information Base for High Capacity Networks", draft-ietf-rmonmib-hcrmon-06.txt, International Network Services, June 1999. [RFC1155] Rose, M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", RFC 1155, STD 16, Performance Systems International, Hughes LAN Systems, May 1990. [RFC1157] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol", RFC 1157, STD 15, SNMP Research, Performance Systems International, Performance Systems International, MIT Laboratory for Computer Science, May 1990. [RFC1212] Rose, M., and K. McCloghrie, "Concise MIB Definitions", RFC 1212, STD 16, Performance Systems International, Hughes LAN Systems, March 1991. Expires June 2000 [Page 10] Internet-Draft High Capacity Data Types December 1999 [RFC1215] M. Rose, "A Convention for Defining Traps for use with the SNMP", RFC 1215, Performance Systems International, March 1991. [RFC1901] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Introduction to Community-based SNMPv2", RFC 1901, SNMP Research, Inc., Cisco Systems, Inc., Dover Beach Consulting, Inc., International Network Services, January 1996. [RFC1905] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Protocol Operations for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1905, SNMP Research, Inc., Cisco Systems, Inc., Dover Beach Consulting, Inc., International Network Services, January 1996. [RFC1906] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Transport Mappings for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1906, SNMP Research, Inc., Cisco Systems, Inc., Dover Beach Consulting, Inc., International Network Services, January 1996. [RFC2021] S. Waldbusser, "Remote Network Monitoring MIB (RMON-2)", RFC 2021, International Network Services, January 1997. [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 3", RFC 2026, Harvard University, October, 1996. [RFC2570] Case, J., Mundy, R., Partain, D., and B. Stewart, "Introduction to Version 3 of the Internet-standard Network Management Framework", RFC 2570, SNMP Research, Inc., TIS Labs at Network Associates, Inc., Ericsson, Cisco Systems, April 1999. [RFC2571] Harrington, D., Presuhn, R., and B. Wijnen, "An Architecture for Describing SNMP Management Frameworks", RFC 2571, Cabletron Systems, Inc., BMC Software, Inc., IBM T. J. Watson Research, April 1999. Expires June 2000 [Page 11] Internet-Draft High Capacity Data Types December 1999 [RFC2572] Case, J., Harrington D., Presuhn R., and B. Wijnen, "Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)", RFC 2572, SNMP Research, Inc., Cabletron Systems, Inc., BMC Software, Inc., IBM T. J. Watson Research, April 1999. [RFC2573] Levi, D., Meyer, P., and B. Stewart, "SNMPv3 Applications", RFC 2573, SNMP Research, Inc., Secure Computing Corporation, Cisco Systems, April 1999. [RFC2574] Blumenthal, U., and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", RFC 2574, IBM T. J. Watson Research, April 1999. [RFC2575] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", RFC 2575, IBM T. J. Watson Research, BMC Software, Inc., Cisco Systems, Inc., April 1999. [RFC2578] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, "Structure of Management Information Version 2 (SMIv2)", RFC 2578, STD 58, Cisco Systems, SNMPinfo, TU Braunschweig, SNMP Research, First Virtual Holdings, International Network Services, April 1999. [RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, "Textual Conventions for SMIv2", RFC 2579, STD 58, Cisco Systems, SNMPinfo, TU Braunschweig, SNMP Research, First Virtual Holdings, International Network Services, April 1999. [RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, "Conformance Statements for SMIv2", RFC 2580, STD 58, Cisco Systems, SNMPinfo, TU Braunschweig, SNMP Research, First Virtual Holdings, International Network Services, April 1999. Expires June 2000 [Page 12] Internet-Draft High Capacity Data Types December 1999 10. Security Considerations There are no security issues raised by this document. Expires June 2000 [Page 13] Internet-Draft High Capacity Data Types December 1999 11. Authors' Addresses Andy Bierman Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134 USA Phone: +1 408-527-3711 Email: abierman@cisco.com Keith McCloghrie Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134 USA Phone: +1 408-526-5260 Email: kzm@cisco.com Randy Presuhn BMC Software, Inc. Office 1-3141 2141 North First Street San Jose, California 95131 USA Phone: +1 408 546-1006 EMail: rpresuhn@bmc.com Expires June 2000 [Page 14] Internet-Draft High Capacity Data Types December 1999 12. Full Copyright Statement Copyright (C) The Internet Society (1999). All Rights Reserved. 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