Network Working Group F. Strauss
Internet-Draft TU Braunschweig
Expires: April 28, 2004 J. Schoenwaelder
International University Bremen
October 29, 2003
SMIng Core Modules
draft-irtf-nmrg-sming-modules-04
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
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This Internet-Draft will expire on April 28, 2004.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
SMIng (Structure of Management Information, Next Generation)
[RFCxxx1] is a protocol-independent data definition language for
management information. This memo presents an SMIng module which
defines a set of derived types for common purposes such as counters,
date and time related types, and various string types.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. NMRG-SMING . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Security Considerations . . . . . . . . . . . . . . . . . . . 12
4. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12
Normative References . . . . . . . . . . . . . . . . . . . . . 13
Informative References . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 13
Intellectual Property and Copyright Statements . . . . . . . . 15
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1. Introduction
Most SMIng [RFCxxx1] modules are built on top of the definitions of
some commonly used derived types. The definitions of these derived
types are contained in the NMRG-SMING module which is contained in
this memo. Its derived types are generally applicable for modelling
all areas of management information. Among these derived types are
counter types, string types and date and time related types.
This module is derived from RFC 2578 [RFC2578] and RFC 2579
[RFC2579].
2. NMRG-SMING
module NMRG-SMING {
organization "IRTF Network Management Research Group (NMRG)";
contact "IRTF Network Management Research Group (NMRG)
http://www.ibr.cs.tu-bs.de/projects/nmrg/
Frank Strauss
TU Braunschweig
Muehlenpfordtstrasse 23
38106 Braunschweig
Germany
Phone: +49 531 391 3266
EMail: strauss@ibr.cs.tu-bs.de
Juergen Schoenwaelder
International University Bremen
P.O. Box 750 561
28725 Bremen
Germany
Phone: +49 421 200 3587
EMail: j.schoenwaelder@iu-bremen.de";
description "Core type definitions for SMIng. Several
type definitions are SMIng versions of
similar SMIv2 or SPPI definitions.
Copyright (C) The Internet Society (2003).
All Rights Reserved.
This version of this module is part of
RFC XXXX, see the RFC itself for full
legal notices.";
revision {
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date "2003-10-29";
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
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).";
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: TimeStamp32,
TimeStamp64, DateAndTime, TimeTicks32 or TimeTicks64
(other types defined in this module).
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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.";
};
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).";
};
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
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appropriate type, to indicate the last discontinuity.
Examples of appropriate types include: TimeStamp32,
TimeStamp64, DateAndTime, TimeTicks32 or TimeTicks64
(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'.
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
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"******* 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.";
reference
"RFC 2578, Sections 2. and 7.1.5.";
};
typedef TimeTicks32 {
type Unsigned32;
description
"The TimeTicks32 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 TimeStamp32 type (defined in this
module) is based on the TimeTicks32 type.";
reference
"RFC 2578, Sections 2. and 7.1.8.";
};
typedef TimeTicks64 {
type Unsigned64;
description
"The TimeTicks64 type represents a non-negative integer
which represents the time, modulo 2^64
(18446744073709551616 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 TimeStamp64 type (defined in this
module) is based on the TimeTicks64 type.";
};
typedef TimeStamp32 {
type TimeTicks32;
description
"The value of an associated TimeTicks32 attribute at
which a specific occurrence happened. The specific
occurrence must be defined in the description of any
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attribute defined using this type. When the specific
occurrence occurred prior to the last time the
associated TimeTicks32 attribute was zero, then the
TimeStamp32 value is zero. Note that this requires all
TimeStamp32 values to be reset to zero when the value of
the associated TimeTicks32 attribute reaches 497+ days
and wraps around to zero.
The associated TimeTicks32 attribute should be specified
in the description of any attribute using this type.
If no TimeTicks32 attribute has been specified, the
default scalar attribute sysUpTime is used.";
reference
"RFC 2579, Section 2.";
};
typedef TimeStamp64 {
type TimeTicks64;
description
"The value of an associated TimeTicks64 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 the associated TimeTicks64
attribute was zero, then the TimeStamp64 value is zero.
The associated TimeTicks64 attribute must be specified in
the description of any attribute using this
type. TimeTicks32 attributes must not be used as
associated attributes.";
};
typedef TimeInterval32 {
type Integer32 (0..2147483647);
description
"A period of time, measured in units of 0.01 seconds.
The TimeInterval32 type uses Integer32 rather than
Unsigned32 for compatibility with RFC 2579.";
reference
"RFC 2579, Section 2.";
};
typedef TimeInterval64 {
type Integer64;
description
"A period of time, measured in units of 0.01 seconds.
Note that negative values are allowed.";
};
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typedef DateAndTime {
type OctetString (8 | 11);
default 0x0000000000000000000000;
format "2d-1d-1d,1d:1d:1d.1d,1a1d:1d";
description
"A date-time specification.
field octets contents range
----- ------ -------- -----
1 1-2 year* 0..65535
2 3 month 1..12 | 0
3 4 day 1..31 | 0
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 {
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type OctetString;
format "1x:";
description
"Represents media- or physical-level addresses.";
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
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- 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
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.
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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 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.";
};
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 derived types which may be used by other SMIng
modules to define management objects. These definitions have no
security impact on the Internet.
4. Acknowledgments
Some definitions in this document are derived from RFC 2578 [RFC2578]
and RFC 2579 [RFC2579], which were written by K. McCloghrie, D.
Perkins, J. Schoenwaelder, J. Case, M. Rose, and S. Waldbusser.
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Normative References
[RFCxxx1] Strauss, F. and J. Schoenwaelder, "SMIng - Next Generation
Structure of Management Information",
draft-irtf-nmrg-sming-06.txt, October 2003.
Informative References
[RFC854] Postel, J. and J. Reynolds, "TELNET Protocol
Specification", RFC 854, STD 8, May 1983.
[RFC2279] Yergeau, F., "UTF-8, a transformation format of ISO
10646", RFC 2279, January 1998.
[RFC2571] Harrington, D., Presuhn, R. and B. Wijnen, "An
Architecture for Describing SNMP Management Frameworks",
RFC 2571, 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 59, April
1999.
[RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M. and S. Waldbusser, "Textual Conventions for
SMIv2", RFC 2579, STD 59, April 1999.
Authors' Addresses
Frank Strauss
TU Braunschweig
Muehlenpfordtstrasse 23
38106 Braunschweig
Germany
Phone: +49 531 391 3266
EMail: strauss@ibr.cs.tu-bs.de
URI: http://www.ibr.cs.tu-bs.de/
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Juergen Schoenwaelder
International University Bremen
P.O. Box 750 561
28725 Bremen
Germany
Phone: +49 421 200 3587
EMail: j.schoenwaelder@iu-bremen.de
URI: http://www.eecs.iu-bremen.de/
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Full Copyright Statement
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This document and translations of it may be copied and furnished to
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BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
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HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
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Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
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