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rfc:rfc1443
        Network Working Group                                  J. Case
        Request for Comments: 1443                 SNMP Research, Inc.
                                                         K. McCloghrie
                                                    Hughes LAN Systems
                                                               M. Rose
                                          Dover Beach Consulting, Inc.
                                                         S. Waldbusser
                                            Carnegie Mellon University
                                                            April 1993
                             Textual Conventions
                             for version 2 of the
                 Simple Network Management Protocol (SNMPv2)
        Status of this Memo
        This RFC specifes an IAB standards track protocol for the
        Internet community, and requests discussion and suggestions
        for improvements.  Please refer to the current edition of the
        "IAB Official Protocol Standards" for the standardization
        state and status of this protocol.  Distribution of this memo
        is unlimited.
        Table of Contents
        1 Introduction ..........................................    2
        1.1 A Note on Terminology ...............................    3
        2 Definitions ...........................................    4
        3 Mapping of the TEXTUAL-CONVENTION macro ...............   22
        3.1 Mapping of the DISPLAY-HINT clause ..................   22
        3.2 Mapping of the STATUS clause ........................   24
        3.3 Mapping of the DESCRIPTION clause ...................   24
        3.4 Mapping of the REFERENCE clause .....................   24
        3.5 Mapping of the SYNTAX clause ........................   24
        4 Acknowledgements ......................................   26
        5 References ............................................   30
        6 Security Considerations ...............................   31
        7 Authors' Addresses ....................................   31
        Case, McCloghrie, Rose & Waldbusser                   [Page 1]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        1.  Introduction
        A network management system contains: several (potentially
        many) nodes, each with a processing entity, termed an agent,
        which has access to management instrumentation; at least one
        management station; and, a management protocol, used to convey
        management information between the agents and management
        stations.  Operations of the protocol are carried out under an
        administrative framework which defines both authentication and
        authorization policies.
        Network management stations execute management applications
        which monitor and control network elements.  Network elements
        are devices such as hosts, routers, terminal servers, etc.,
        which are monitored and controlled through access to their
        management information.
        Management information is viewed as a collection of managed
        objects, residing in a virtual information store, termed the
        Management Information Base (MIB).  Collections of related
        objects are defined in MIB modules.  These modules are written
        using a subset of OSI's Abstract Syntax Notation One (ASN.1)
        [1], termed the Structure of Management Information (SMI) [2].
        When designing a MIB module, it is often useful to new define
        types similar to those defined in the SMI.  In comparison to a
        type defined in the SMI, each of these new types has a
        different name, a similar syntax, but a more precise
        semantics.  These newly defined types are termed textual
        conventions, and are used for the convenience of humans
        reading the MIB module.  It is the purpose of this document to
        define the initial set of textual conventions available to all
        MIB modules.
        Objects defined using a textual convention are always encoded
        by means of the rules that define their primitive type.
        However, textual conventions often have special semantics
        associated with them.  As such, an ASN.1 macro, TEXTUAL-
        CONVENTION, is used to concisely convey the syntax and
        semantics of a textual convention.
        For all textual conventions defined in an information module,
        the name shall be unique and mnemonic, and shall not exceed 64
        characters in length.  All names used for the textual
        conventions defined in all "standard" information modules
        Case, McCloghrie, Rose & Waldbusser                   [Page 2]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        shall be unique.
        1.1.  A Note on Terminology
        For the purpose of exposition, the original Internet-standard
        Network Management Framework, as described in RFCs 1155, 1157,
        and 1212, is termed the SNMP version 1 framework (SNMPv1).
        The current framework is termed the SNMP version 2 framework
        (SNMPv2).
        Case, McCloghrie, Rose & Waldbusser                   [Page 3]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        2.  Definitions
        SNMPv2-TC DEFINITIONS ::= BEGIN
        IMPORTS
            ObjectSyntax, Integer32, TimeTicks
                FROM SNMPv2-SMI;
  1. - definition of textual conventions
        TEXTUAL-CONVENTION MACRO ::=
        BEGIN
            TYPE NOTATION ::=
                          DisplayPart
                          "STATUS" Status
                          "DESCRIPTION" Text
                          ReferPart
                          "SYNTAX" type(Syntax)
            VALUE NOTATION ::=
                          value(VALUE Syntax)
            DisplayPart ::=
                          "DISPLAY-HINT" Text
                        | empty
            Status ::=
                          "current"
                        | "deprecated"
                        | "obsolete"
            ReferPart ::=
                          "REFERENCE" Text
                        | empty
  1. - uses the NVT ASCII character set

Text ::= """" string """"

        END
        Case, McCloghrie, Rose & Waldbusser                   [Page 4]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        DisplayString ::= TEXTUAL-CONVENTION
            DISPLAY-HINT "255a"
            STATUS       current
            DESCRIPTION
                    "Represents textual information taken from the NVT
                    ASCII character set, as defined in pages 4, 10-11
                    of RFC 854.  Any object defined using this syntax
                    may not exceed 255 characters in length."
            SYNTAX       OCTET STRING (SIZE (0..255))
        PhysAddress ::= TEXTUAL-CONVENTION
            DISPLAY-HINT "1x:"
            STATUS       current
            DESCRIPTION
                    "Represents media- or physical-level addresses."
            SYNTAX       OCTET STRING
        MacAddress ::= TEXTUAL-CONVENTION
            DISPLAY-HINT "1x:"
            STATUS       current
            DESCRIPTION
                    "Represents an 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."
            SYNTAX       OCTET STRING (SIZE (6))
        TruthValue ::= TEXTUAL-CONVENTION
            STATUS       current
            DESCRIPTION
                    "Represents a boolean value."
            SYNTAX       INTEGER { true(1), false(2) }
        Case, McCloghrie, Rose & Waldbusser                   [Page 5]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        TestAndIncr ::= TEXTUAL-CONVENTION
            STATUS       current
            DESCRIPTION
                    "Represents integer-valued information used for
                    atomic operations.  When the management protocol
                    is used to specify that an object instance having
                    this syntax is to be modified, the new value
                    supplied via the management protocol must
                    precisely match the value presently held by the
                    instance.  If not, the management protocol set
                    operation fails with an error of
                    'inconsistentValue'.  Otherwise, if the current
                    value is the maximum value of 2^31-1 (2147483647
                    decimal), then the value held by the instance is
                    wrapped to zero; otherwise, the value held by the
                    instance is incremented by one.  (Note that
                    regardless of whether the management protocol set
                    operation succeeds, the variable-binding in the
                    request and response PDUs are identical.)
                    The value of the ACCESS clause for objects having
                    this syntax is either 'read-write' or 'read-
                    create'.  When an instance of a columnar object
                    having this syntax is created, any value may be
                    supplied via the management protocol."
            SYNTAX       INTEGER (0..2147483647)
        Case, McCloghrie, Rose & Waldbusser                   [Page 6]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        AutonomousType ::= TEXTUAL-CONVENTION
            STATUS       current
            DESCRIPTION
                    "Represents an independently extensible type
                    identification value.  It may, for example,
                    indicate a particular sub-tree with further MIB
                    definitions, or define a particular type of
                    protocol or hardware."
            SYNTAX       OBJECT IDENTIFIER
        InstancePointer ::= TEXTUAL-CONVENTION
            STATUS       current
            DESCRIPTION
                    "A pointer to a specific instance of a conceptual
                    row of a MIB table in the managed device.  By
                    convention, it is the name of the particular
                    instance of the first columnar object in the
                    conceptual row."
            SYNTAX       OBJECT IDENTIFIER
        Case, McCloghrie, Rose & Waldbusser                   [Page 7]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        RowStatus ::= TEXTUAL-CONVENTION
            STATUS       current
            DESCRIPTION
                    "The RowStatus textual convention is used to
                    manage the creation and deletion of conceptual
                    rows, and is used as the value of the SYNTAX
                    clause for the status column of a conceptual row
                    (as described in Section 7.7.1 of [2].)
                    The status column has six defined values:
  1. 'active', which indicates that the

conceptual row is available for use by the

                         managed device;
  1. 'notInService', which indicates that the

conceptual row exists in the agent, but is

                         unavailable for use by the managed device
                         (see NOTE below);
  1. 'notReady', which indicates that the

conceptual row exists in the agent, but is

                         missing information necessary in order to be
                         available for use by the managed device;
  1. 'createAndGo', which is supplied by a

management station wishing to create a new

                         instance of a conceptual row and to have it
                         available for use by the managed device;
  1. 'createAndWait', which is supplied by a

management station wishing to create a new

                         instance of a conceptual row but not to have
                         it available for use by the managed device;
                         and,
  1. 'destroy', which is supplied by a

management station wishing to delete all of

                         the instances associated with an existing
                         conceptual row.
                    Whereas five of the six values (all except
                    'notReady') may be specified in a management
                    protocol set operation, only three values will be
                    returned in response to a management protocol
        Case, McCloghrie, Rose & Waldbusser                   [Page 8]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                    retrieval operation: 'notReady', 'notInService' or
                    'active'.  That is, when queried, an existing
                    conceptual row has only three states: it is either
                    available for use by the managed device (the
                    status column has value 'active'); it is not
                    available for use by the managed device, though
                    the agent has sufficient information to make it so
                    (the status column has value 'notInService'); or,
                    it is not available for use by the managed device,
                    because the agent lacks sufficient information
                    (the status column has value 'notReady').
                                        NOTE WELL
                         This textual convention may be used for a MIB
                         table, irrespective of whether the values of
                         that table's conceptual rows are able to be
                         modified while it is active, or whether its
                         conceptual rows must be taken out of service
                         in order to be modified.  That is, it is the
                         responsibility of the DESCRIPTION clause of
                         the status column to specify whether the
                         status column must be 'notInService' in order
                         for the value of some other column of the
                         same conceptual row to be modified.
        Case, McCloghrie, Rose & Waldbusser                   [Page 9]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                    To summarize the effect of having a conceptual row
                    with a status column having a SYNTAX clause value
                    of RowStatus, consider the following state
                    diagram:
                                          STATE
               +--------------+-----------+-------------+-------------
               |      A       |     B     |      C      |      D
               |              |status col.|status column|
               |status column |    is     |      is     |status column
     ACTION    |does not exist|  notReady | notInService|  is active
 --------------+--------------+-----------+-------------+-------------
 set status    |noError    ->D|inconsist- |inconsistent-|inconsistent-
 column to     |       or     |   entValue|        Value|        Value
 createAndGo   |inconsistent- |           |             |
               |         Value|           |             |
 --------------+--------------+-----------+-------------+-------------
 set status    |noError  see 1|inconsist- |inconsistent-|inconsistent-
 column to     |       or     |   entValue|        Value|        Value
 createAndWait |wrongValue    |           |             |
 --------------+--------------+-----------+-------------+-------------
 set status    |inconsistent- |inconsist- |noError      |noError
 column to     |         Value|   entValue|             |
 active        |              |           |             |
               |              |     or    |             |
               |              |           |             |
               |              |see 2   ->D|          ->D|          ->D
 --------------+--------------+-----------+-------------+-------------
 set status    |inconsistent- |inconsist- |noError      |noError   ->C
 column to     |         Value|   entValue|             |
 notInService  |              |           |             |
               |              |     or    |             |      or
               |              |           |             |
               |              |see 3   ->C|          ->C|wrongValue
 --------------+--------------+-----------+-------------+-------------
 set status    |noError       |noError    |noError      |noError
 column to     |              |           |             |
 destroy       |           ->A|        ->A|          ->A|          ->A
 --------------+--------------+-----------+-------------+-------------
 set any other |see 4         |noError    |noError      |noError
 column to some|              |           |             |
 value         |           ->A|      see 1|          ->C|          ->D
 --------------+--------------+-----------+-------------+-------------
        Case, McCloghrie, Rose & Waldbusser                  [Page 10]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                    (1) goto B or C, depending on information
                    available to the agent.
                    (2) if other variable bindings included in the
                    same PDU, provide values for all columns which are
                    missing but required, then return noError and goto
                    D.
                    (3) if other variable bindings included in the
                    same PDU, provide values for all columns which are
                    missing but required, then return noError and goto
                    C.
                    (4) at the discretion of the agent, either noError
                    or inconsistentValue may be returned.
                    NOTE: Other processing of the set request may
                    result in a response other than noError being
                    returned, e.g., wrongValue, noCreation, etc.
                                 Conceptual Row Creation
                    There are four potential interactions when
                    creating a conceptual row: selecting an instance-
                    identifier which is not in use; creating the
                    conceptual row; initializing any objects for which
                    the agent does not supply a default; and, making
                    the conceptual row available for use by the
                    managed device.
                    Interaction 1: Selecting an Instance-Identifier
                    The algorithm used to select an instance-
                    identifier varies for each conceptual row.  In
                    some cases, the instance-identifier is
                    semantically significant, e.g., the destination
                    address of a route, and a management station
                    selects the instance-identifier according to the
                    semantics.
                    In other cases, the instance-identifier is used
                    solely to distinguish conceptual rows, and a
                    management station without specific knowledge of
                    the conceptual row might examine the instances
        Case, McCloghrie, Rose & Waldbusser                  [Page 11]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                    present in order to determine an unused instance-
                    identifier.  (This approach may be used, but it is
                    often highly sub-optimal; however, it is also a
                    questionable practice for a naive management
                    station to attempt conceptual row creation.)
                    Alternately, the MIB module which defines the
                    conceptual row might provide one or more objects
                    which provide assistance in determining an unused
                    instance-identifier.  For example, if the
                    conceptual row is indexed by an integer-value,
                    then an object having an integer-valued SYNTAX
                    clause might be defined for such a purpose,
                    allowing a management station to issue a
                    management protocol retrieval operation.  In order
                    to avoid unnecessary collisions between competing
                    management stations, 'adjacent' retrievals of this
                    object should be different.
                    Finally, the management station could select a
                    pseudo-random number to use as the index.  In the
                    event that this index was already in use and an
                    inconsistentValue was returned in response to the
                    management protocol set operation, the management
                    station should simply select a new pseudo-random
                    number and retry the operation.
                    A MIB designer should choose between the two
                    latter algorithms based on the size of the table
                    (and therefore the efficiency of each algorithm).
                    For tables in which a large number of entries are
                    expected, it is recommended that a MIB object be
                    defined that returns an acceptable index for
                    creation.  For tables with small numbers of
                    entries, it is recommended that the latter
                    pseudo-random index mechanism be used.
                    Interaction 2: Creating the Conceptual Row
                    Once an unused instance-identifier has been
                    selected, the management station determines if it
                    wishes to create and activate the conceptual row
                    in one transaction or in a negotiated set of
                    interactions.
        Case, McCloghrie, Rose & Waldbusser                  [Page 12]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                    Interaction 2a: Creating and Activating the
                    Conceptual Row
                    The management station must first determine the
                    column requirements, i.e., it must determine those
                    columns for which it must or must not provide
                    values.  Depending on the complexity of the table
                    and the management station's knowledge of the
                    agent's capabilities, this determination can be
                    made locally by the management station.
                    Alternately, the management station issues a
                    management protocol get operation to examine all
                    columns in the conceptual row that it wishes to
                    create.  In response, for each column, there are
                    three possible outcomes:
  1. a value is returned, indicating that some

other management station has already created

                         this conceptual row.  We return to
                         interaction 1.
  1. the exception 'noSuchInstance' is returned,

indicating that the agent implements the

                         object-type associated with this column, and
                         that this column in at least one conceptual
                         row would be accessible in the MIB view used
                         by the retrieval were it to exist. For those
                         columns to which the agent provides read-
                         create access, the 'noSuchInstance' exception
                         tells the management station that it should
                         supply a value for this column when the
                         conceptual row is to be created.
  1. the exception 'noSuchObject' is returned,

indicating that the agent does not implement

                         the object-type associated with this column
                         or that there is no conceptual row for which
                         this column would be accessible in the MIB
                         view used by the retrieval.  As such, the
                         management station can not issue any
                         management protocol set operations to create
                         an instance of this column.
                    Once the column requirements have been determined,
                    a management protocol set operation is accordingly
        Case, McCloghrie, Rose & Waldbusser                  [Page 13]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                    issued.  This operation also sets the new instance
                    of the status column to 'createAndGo'.
                    When the agent processes the set operation, it
                    verifies that it has sufficient information to
                    make the conceptual row available for use by the
                    managed device.  The information available to the
                    agent is provided by two sources: the management
                    protocol set operation which creates the
                    conceptual row, and, implementation-specific
                    defaults supplied by the agent (note that an agent
                    must provide implementation-specific defaults for
                    at least those objects which it implements as
                    read-only).  If there is sufficient information
                    available, then the conceptual row is created, a
                    'noError' response is returned, the status column
                    is set to 'active', and no further interactions
                    are necessary (i.e., interactions 3 and 4 are
                    skipped).  If there is insufficient information,
                    then the conceptual row is not created, and the
                    set operation fails with an error of
                    'inconsistentValue'.  On this error, the
                    management station can issue a management protocol
                    retrieval operation to determine if this was
                    because it failed to specify a value for a
                    required column, or, because the selected instance
                    of the status column already existed.  In the
                    latter case, we return to interaction 1.  In the
                    former case, the management station can re-issue
                    the set operation with the additional information,
                    or begin interaction 2 again using 'createAndWait'
                    in order to negotiate creation of the conceptual
                    row.
        Case, McCloghrie, Rose & Waldbusser                  [Page 14]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                                        NOTE WELL
                         Regardless of the method used to determine
                         the column requirements, it is possible that
                         the management station might deem a column
                         necessary when, in fact, the agent will not
                         allow that particular columnar instance to be
                         created or written.  In this case, the
                         management protocol set operation will fail
                         with an error such as 'noCreation' or
                         'notWritable'.  In this case, the management
                         station decides whether it needs to be able
                         to set a value for that particular columnar
                         instance.  If not, the management station
                         re-issues the management protocol set
                         operation, but without setting a value for
                         that particular columnar instance; otherwise,
                         the management station aborts the row
                         creation algorithm.
                    Interaction 2b: Negotiating the Creation of the
                    Conceptual Row
                    The management station issues a management
                    protocol set operation which sets the desired
                    instance of the status column to 'createAndWait'.
                    If the agent is unwilling to process a request of
                    this sort, the set operation fails with an error
                    of 'wrongValue'.  (As a consequence, such an agent
                    must be prepared to accept a single management
                    protocol set operation, i.e., interaction 2a
                    above, containing all of the columns indicated by
                    its column requirements.) Otherwise, the
                    conceptual row is created, a 'noError' response is
                    returned, and the status column is immediately set
                    to either 'notInService' or 'notReady', depending
                    on whether it has sufficient information to make
                    the conceptual row available for use by the
                    managed device.  If there is sufficient
                    information available, then the status column is
                    set to 'notInService'; otherwise, if there is
                    insufficient information, then the status column
                    is set to 'notReady'.  Regardless, we proceed to
                    interaction 3.
        Case, McCloghrie, Rose & Waldbusser                  [Page 15]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                    Interaction 3: Initializing non-defaulted Objects
                    The management station must now determine the
                    column requirements.  It issues a management
                    protocol get operation to examine all columns in
                    the created conceptual row.  In the response, for
                    each column, there are three possible outcomes:
  1. a value is returned, indicating that the

agent implements the object-type associated

                         with this column and had sufficient
                         information to provide a value.  For those
                         columns to which the agent provides read-
                         create access, a value return tells the
                         management station that it may issue
                         additional management protocol set
                         operations, if it desires, in order to change
                         the value associated with this column.
  1. the exception 'noSuchInstance' is returned,

indicating that the agent implements the

                         object-type associated with this column, and
                         that this column in at least one conceptual
                         row would be accessible in the MIB view used
                         by the retrieval were it to exist. However,
                         the agent does not have sufficient
                         information to provide a value, and until a
                         value is provided, the conceptual row may not
                         be made available for use by the managed
                         device.  For those columns to which the agent
                         provides read-create access, the
                         'noSuchInstance' exception tells the
                         management station that it must issue
                         additional management protocol set
                         operations, in order to provide a value
                         associated with this column.
  1. the exception 'noSuchObject' is returned,

indicating that the agent does not implement

                         the object-type associated with this column
                         or that there is no conceptual row for which
                         this column would be accessible in the MIB
                         view used by the retrieval.  As such, the
                         management station can not issue any
                         management protocol set operations to create
        Case, McCloghrie, Rose & Waldbusser                  [Page 16]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                         an instance of this column.
                    If the value associated with the status column is
                    'notReady', then the management station must first
                    deal with all 'noSuchInstance' columns, if any.
                    Having done so, the value of the status column
                    becomes 'notInService', and we proceed to
                    interaction 4.
                    Interaction 4: Making the Conceptual Row Available
                    Once the management station is satisfied with the
                    values associated with the columns of the
                    conceptual row, it issues a management protocol
                    set operation to set the status column to
                    'active'.  If the agent has sufficient information
                    to make the conceptual row available for use by
                    the managed device, the management protocol set
                    operation succeeds (a 'noError' response is
                    returned).  Otherwise, the management protocol set
                    operation fails with an error of
                    'inconsistentValue'.
                                        NOTE WELL
                         A conceptual row having a status column with
                         value 'notInService' or 'notReady' is
                         unavailable to the managed device.  As such,
                         it is possible for the managed device to
                         create its own instances during the time
                         between the management protocol set operation
                         which sets the status column to
                         'createAndWait' and the management protocol
                         set operation which sets the status column to
                         'active'.  In this case, when the management
                         protocol set operation is issued to set the
                         status column to 'active', the values held in
                         the agent supersede those used by the managed
                         device.
                    If the management station is prevented from
                    setting the status column to 'active' (e.g., due
                    to management station or network failure) the
                    conceptual row will be left in the 'notInService'
                    or 'notReady' state, consuming resources
        Case, McCloghrie, Rose & Waldbusser                  [Page 17]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
                    indefinitely.  The agent must detect conceptual
                    rows that have been in either state for an
                    abnormally long period of time and remove them.
                    This period of time should be long enough to allow
                    for human response time (including 'think time')
                    between the creation of the conceptual row and the
                    setting of the status to 'active'.  It is
                    suggested that this period be approximately 5
                    minutes in length.
                                Conceptual Row Suspension
                    When a conceptual row is 'active', the management
                    station may issue a management protocol set
                    operation which sets the instance of the status
                    column to 'notInService'.  If the agent is
                    unwilling to do so, the set operation fails with
                    an error of 'wrongValue'.  Otherwise, the
                    conceptual row is taken out of service, and a
                    'noError' response is returned.  It is the
                    responsibility of the the DESCRIPTION clause of
                    the status column to indicate under what
                    circumstances the status column should be taken
                    out of service (e.g., in order for the value of
                    some other column of the same conceptual row to be
                    modified).
                                 Conceptual Row Deletion
                    For deletion of conceptual rows, a management
                    protocol set operation is issued which sets the
                    instance of the status column to 'destroy'.  This
                    request may be made regardless of the current
                    value of the status column (e.g., it is possible
                    to delete conceptual rows which are either
                    'notReady', 'notInService' or 'active'.) If the
                    operation succeeds, then all instances associated
                    with the conceptual row are immediately removed."
        Case, McCloghrie, Rose & Waldbusser                  [Page 18]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
            SYNTAX       INTEGER {
                             -- the following two values are states:
                             -- these values may be read or written
                             active(1),
                             notInService(2),
  1. - the following value is a state:
  2. - this value may be read, but not written

notReady(3),

  1. - the following three values are
  2. - actions: these values may be written,
  3. - but are never read

createAndGo(4),

                             createAndWait(5),
                             destroy(6)
                         }
        Case, McCloghrie, Rose & Waldbusser                  [Page 19]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        TimeStamp ::= TEXTUAL-CONVENTION
            STATUS       current
            DESCRIPTION
                    "The value of MIB-II's sysUpTime object at which a
                    specific occurrence happened.  The specific
                    occurrence must be defined in the description of
                    any object defined using this type."
            SYNTAX       TimeTicks
        TimeInterval ::= TEXTUAL-CONVENTION
            STATUS       current
            DESCRIPTION
                    "A period of time, measured in units of 0.01
                    seconds."
            SYNTAX       INTEGER (0..2147483647)
        Case, McCloghrie, Rose & Waldbusser                  [Page 20]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        DateAndTime ::= TEXTUAL-CONVENTION
            DISPLAY-HINT "2d-1d-1d,1d:1d:1d.1d,1a1d:1d"
            STATUS       current
            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..11
                     10      11    minutes from UTC          0..59
                    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."
            SYNTAX       OCTET STRING (SIZE (8 | 11))
        END
        Case, McCloghrie, Rose & Waldbusser                  [Page 21]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        3.  Mapping of the TEXTUAL-CONVENTION macro
        The TEXTUAL-CONVENTION macro is used to convey the syntax and
        semantics associated with a textual convention.  It should be
        noted that the expansion of the TEXTUAL-CONVENTION macro is
        something which conceptually happens during implementation and
        not during run-time.
        For all descriptors appearing in an information module, the
        descriptor shall be unique and mnemonic, and shall not exceed
        64 characters in length.  Further, the hyphen is not allowed
        as a character in the name of any textual convention.
        3.1.  Mapping of the DISPLAY-HINT clause
        The DISPLAY-HINT clause, which need not be present, gives a
        hint as to how the value of an instance of an object with the
        syntax defined using this textual convention might be
        displayed.  The DISPLAY-HINT clause may only be present when
        the syntax has an underlying primitive type of INTEGER or
        OCTET STRING.
        When the syntax has an underlying primitive type of INTEGER,
        the hint consists of a single character suggesting a display
        format, either: 'x' for hexadecimal, 'd' for decimal, or 'o'
        for octal, or 'b' for binary.
        When the syntax has an underlying primitive type of OCTET
        STRING, the hint consists of one or more octet-format
        specifications.  Each specification consists of five parts,
        with each part using and removing zero or more of the next
        octets from the value and producing the next zero or more
        characters to be displayed.  The octets within the value are
        processed in order of significance, most significant first.
        The five parts of a octet-format specification are:
        (1)  the (optional) repeat indicator; if present, this part is
             a '*', and indicates that the current octet of the value
             is to be used as the repeat count.  The repeat count is
             an unsigned integer (which may be zero) which specifies
             how many times the remainder of this octet-format
             specification should be successively applied.  If the
             repeat indicator is not present, the repeat count is one.
        Case, McCloghrie, Rose & Waldbusser                  [Page 22]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        (2)  the octet length: one or more decimal digits specifying
             the number of octets of the value to be used and
             formatted by this octet-specification.  Note that the
             octet length can be zero.  If less than this number of
             octets remain in the value, then the lesser number of
             octets are used.
        (3)  the display format, either: 'x' for hexadecimal, 'd' for
             decimal, 'o' for octal, or 'a' for ascii.  If the octet
             length part is greater than one, and the display format
             part refers to a numeric format, then network-byte
             ordering (big-endian encoding) is used interpreting the
             octets in the value.
        (4)  the (optional) display separator character; if present,
             this part is a single character which is produced for
             display after each application of this octet-
             specification; however, this character is not produced
             for display if it would be immediately followed by the
             display of the repeat terminator character for this
             octet-specification.  This character can be any character
             other than a decimal digit and a '*'.
        (5)  the (optional) repeat terminator character, which can be
             present only if the display separator character is
             present and this octet-specification begins with a repeat
             indicator; if present, this part is a single character
             which is produced after all the zero or more repeated
             applications (as given by the repeat count) of this
             octet-specification.  This character can be any character
             other than a decimal digit and a '*'.
        Output of a display separator character or a repeat terminator
        character is suppressed if it would occur as the last
        character of the display.
        If the octets of the value are exhausted before all the
        octet-format specification have been used, then the excess
        specifications are ignored.  If additional octets remain in
        the value after interpreting all the octet-format
        specifications, then the last octet-format specification is
        re-interpreted to process the additional octets, until no
        octets remain in the value.
        Case, McCloghrie, Rose & Waldbusser                  [Page 23]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        3.2.  Mapping of the STATUS clause
        The STATUS clause, which must be present, indicates whether
        this definition is current or historic.
        The values "current", and "obsolete" are self-explanatory.
        The "deprecated" value indicates that the textual convention
        is obsolete, but that an implementor may wish to support that
        object to foster interoperability with older implementations.
        3.3.  Mapping of the DESCRIPTION clause
        The DESCRIPTION clause, which must be present, contains a
        textual definition of the textual convention, which provides
        all semantic definitions necessary for implementation, and
        should embody any information which would otherwise be
        communicated in any ASN.1 commentary annotations associated
        with the object.
        Note that, in order to conform to the ASN.1 syntax, the entire
        value of this clause must be enclosed in double quotation
        marks, and therefore cannot itself contain double quotation
        marks, although the value may be multi-line.
        3.4.  Mapping of the REFERENCE clause
        The REFERENCE clause, which need not be present, contains a
        textual cross-reference to a related item defined in some
        other published work.
        3.5.  Mapping of the SYNTAX clause
        The SYNTAX clause, which must be present, defines abstract
        data structure corresponding to the textual convention.  The
        data structure must be one of the alternatives defined in the
        ObjectSyntax CHOICE [2].
        Full ASN.1 sub-typing is allowed, as appropriate to the
        underingly ASN.1 type, primarily as an aid to implementors in
        understanding the meaning of the textual convention.  Of
        course, sub-typing is not allowed for textual conventions
        derived from either the Counter32 or Counter64 types, but is
        Case, McCloghrie, Rose & Waldbusser                  [Page 24]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        allowed for textual conventions derived from the Gauge32 type.
        Case, McCloghrie, Rose & Waldbusser                  [Page 25]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        4.  Acknowledgements
        PhysAddress (and textual conventions) originated in RFC 1213.
        MacAddress originated in RFCs 1230 and 1231.
        TruthValue originated in RFC 1253.
        AutonomousType and InstancePointer originated in RFC 1316.
        RowStatus originated in RFC 1271.
        A special thanks to Bancroft Scott of Open Systems Solutions,
        Inc., for helping in the definition of the TEXTUAL-CONVENTIONS
        macro.
        Finally, the comments of the SNMP version 2 working group are
        gratefully acknowledged:
             Beth Adams, Network Management Forum
             Steve Alexander, INTERACTIVE Systems Corporation
             David Arneson, Cabletron Systems
             Toshiya Asaba
             Fred Baker, ACC
             Jim Barnes, Xylogics, Inc.
             Brian Bataille
             Andy Bierman, SynOptics Communications, Inc.
             Uri Blumenthal, IBM Corporation
             Fred Bohle, Interlink
             Jack Brown
             Theodore Brunner, Bellcore
             Stephen F. Bush, GE Information Services
             Jeffrey D. Case, University of Tennessee, Knoxville
             John Chang, IBM Corporation
             Szusin Chen, Sun Microsystems
             Robert Ching
             Chris Chiotasso, Ungermann-Bass
             Bobby A. Clay, NASA/Boeing
             John Cooke, Chipcom
             Tracy Cox, Bellcore
             Juan Cruz, Datability, Inc.
             David Cullerot, Cabletron Systems
             Cathy Cunningham, Microcom
             James R. (Chuck) Davin, Bellcore
             Michael Davis, Clearpoint
        Case, McCloghrie, Rose & Waldbusser                  [Page 26]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
             Mike Davison, FiberCom
             Cynthia DellaTorre, MITRE
             Taso N. Devetzis, Bellcore
             Manual Diaz, DAVID Systems, Inc.
             Jon Dreyer, Sun Microsystems
             David Engel, Optical Data Systems
             Mike Erlinger, Lexcel
             Roger Fajman, NIH
             Daniel Fauvarque, Sun Microsystems
             Karen Frisa, CMU
             Shari Galitzer, MITRE
             Shawn Gallagher, Digital Equipment Corporation
             Richard Graveman, Bellcore
             Maria Greene, Xyplex, Inc.
             Michel Guittet, Apple
             Robert Gutierrez, NASA
             Bill Hagerty, Cabletron Systems
             Gary W. Haney, Martin Marietta Energy Systems
             Patrick Hanil, Nokia Telecommunications
             Matt Hecht, SNMP Research, Inc.
             Edward A. Heiner, Jr., Synernetics Inc.
             Susan E. Hicks, Martin Marietta Energy Systems
             Geral Holzhauer, Apple
             John Hopprich, DAVID Systems, Inc.
             Jeff Hughes, Hewlett-Packard
             Robin Iddon, Axon Networks, Inc.
             David Itusak
             Kevin M. Jackson, Concord Communications, Inc.
             Ole J. Jacobsen, Interop Company
             Ronald Jacoby, Silicon Graphics, Inc.
             Satish Joshi, SynOptics Communications, Inc.
             Frank Kastenholz, FTP Software
             Mark Kepke, Hewlett-Packard
             Ken Key, SNMP Research, Inc.
             Zbiginew Kielczewski, Eicon
             Jongyeoi Kim
             Andrew Knutsen, The Santa Cruz Operation
             Michael L. Kornegay, VisiSoft
             Deirdre C. Kostik, Bellcore
             Cheryl Krupczak, Georgia Tech
             Mark S. Lewis, Telebit
             David Lin
             David Lindemulder, AT&T/NCR
             Ben Lisowski, Sprint
             David Liu, Bell-Northern Research
        Case, McCloghrie, Rose & Waldbusser                  [Page 27]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
             John Lunny, The Wollongong Group
             Robert C. Lushbaugh Martin, Marietta Energy Systems
             Michael Luufer, BBN
             Carl Madison, Star-Tek, Inc.
             Keith McCloghrie, Hughes LAN Systems
             Evan McGinnis, 3Com Corporation
             Bill McKenzie, IBM Corporation
             Donna McMaster, SynOptics Communications, Inc.
             John Medicke, IBM Corporation
             Doug Miller, Telebit
             Dave Minnich, FiberCom
             Mohammad Mirhakkak, MITRE
             Rohit Mital, Protools
             George Mouradian, AT&T Bell Labs
             Patrick Mullaney, Cabletron Systems
             Dan Myers, 3Com Corporation
             Rina Nathaniel, Rad Network Devices Ltd.
             Hien V. Nguyen, Sprint
             Mo Nikain
             Tom Nisbet
             William B. Norton, MERIT
             Steve Onishi, Wellfleet Communications, Inc.
             David T. Perkins, SynOptics Communications, Inc.
             Carl Powell, BBN
             Ilan Raab, SynOptics Communications, Inc.
             Richard Ramons, AT&T
             Venkat D. Rangan, Metric Network Systems, Inc.
             Louise Reingold, Sprint
             Sam Roberts, Farallon Computing, Inc.
             Kary Robertson, Concord Communications, Inc.
             Dan Romascanu, Lannet Data Communications Ltd.
             Marshall T. Rose, Dover Beach Consulting, Inc.
             Shawn A. Routhier, Epilogue Technology Corporation
             Chris Rozman
             Asaf Rubissa, Fibronics
             Jon Saperia, Digital Equipment Corporation
             Michael Sapich
             Mike Scanlon, Interlan
             Sam Schaen, MITRE
             John Seligson, Ultra Network Technologies
             Paul A. Serice, Corporation for Open Systems
             Chris Shaw, Banyan Systems
             Timon Sloane
             Robert Snyder, Cisco Systems
             Joo Young Song
        Case, McCloghrie, Rose & Waldbusser                  [Page 28]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
             Roy Spitier, Sprint
             Einar Stefferud, Network Management Associates
             John Stephens, Cayman Systems, Inc.
             Robert L. Stewart, Xyplex, Inc. (chair)
             Kaj Tesink, Bellcore
             Dean Throop, Data General
             Ahmet Tuncay, France Telecom-CNET
             Maurice Turcotte, Racal Datacom
             Warren Vik, INTERACTIVE Systems Corporation
             Yannis Viniotis
             Steven L. Waldbusser, Carnegie Mellon Universitty
             Timothy M. Walden, ACC
             Alice Wang, Sun Microsystems
             James Watt, Newbridge
             Luanne Waul, Timeplex
             Donald E. Westlake III, Digital Equipment Corporation
             Gerry White
             Bert Wijnen, IBM Corporation
             Peter Wilson, 3Com Corporation
             Steven Wong, Digital Equipment Corporation
             Randy Worzella, IBM Corporation
             Daniel Woycke, MITRE
             Honda Wu
             Jeff Yarnell, Protools
             Chris Young, Cabletron
             Kiho Yum, 3Com Corporation
        Case, McCloghrie, Rose & Waldbusser                  [Page 29]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        5.  References
        [1]  Information processing systems - Open Systems
             Interconnection - Specification of Abstract Syntax
             Notation One (ASN.1), International Organization for
             Standardization.  International Standard 8824, (December,
             1987).
        [2]  Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
             "Structure of Management Information for version 2 of the
             Simple Network Management Protocol (SNMPv2)", RFC 1442,
             SNMP Research, Inc., Hughes LAN Systems, Dover Beach
             Consulting, Inc., Carnegie Mellon University, April 1993.
        Case, McCloghrie, Rose & Waldbusser                  [Page 30]
        RFC 1443        Textual Conventions for SNMPv2      April 1993
        6.  Security Considerations
        Security issues are not discussed in this memo.
        7.  Authors' Addresses
             Jeffrey D. Case
             SNMP Research, Inc.
             3001 Kimberlin Heights Rd.
             Knoxville, TN  37920-9716
             US
             Phone: +1 615 573 1434
             Email: case@snmp.com
             Keith McCloghrie
             Hughes LAN Systems
             1225 Charleston Road
             Mountain View, CA  94043
             US
             Phone: +1 415 966 7934
             Email: kzm@hls.com
             Marshall T. Rose
             Dover Beach Consulting, Inc.
             420 Whisman Court
             Mountain View, CA  94043-2186
             US
             Phone: +1 415 968 1052
             Email: mrose@dbc.mtview.ca.us
             Steven Waldbusser
             Carnegie Mellon University
             4910 Forbes Ave
             Pittsburgh, PA  15213
             US
             Phone: +1 412 268 6628
             Email: waldbusser@cmu.edu
        Case, McCloghrie, Rose & Waldbusser                  [Page 31]
/data/webs/external/dokuwiki/data/pages/rfc/rfc1443.txt · Last modified: 1993/04/30 22:08 (external edit)