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rfc:rfc3781

Network Working Group F. Strauss Request for Comments: 3781 TU Braunschweig Category: Experimental J. Schoenwaelder

                                       International University Bremen
                                                              May 2004
    Next Generation Structure of Management Information (SMIng)
     Mappings to the Simple Network Management Protocol (SNMP)

Status of this Memo

 This memo defines an Experimental Protocol for the Internet
 community.  It does not specify an Internet standard of any kind.
 Discussion and suggestions for improvement are requested.
 Distribution of this memo is unlimited.

Copyright Notice

 Copyright (C) The Internet Society (2004).  All Rights Reserved.

Abstract

 SMIng (Structure of Management Information, Next Generation)
 (RFC3780), is a protocol-independent data definition language for
 management information.  This memo defines an SMIng language
 extension that specifies the mapping of SMIng definitions of
 identities, classes, and their attributes and events to dedicated
 definitions of nodes, scalar objects, tables and columnar objects,
 and notifications, for application to the SNMP management framework.

Table of Contents

 1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
 2.  SNMP Based Internet Management . . . . . . . . . . . . . . . .  3
     2.1.   Kinds of Nodes. . . . . . . . . . . . . . . . . . . . .  4
     2.2.   Scalar and Columnar Object Instances. . . . . . . . . .  5
     2.3.   Object Identifier Hierarchy . . . . . . . . . . . . . .  7
 3.  SMIng Data Type Mappings . . . . . . . . . . . . . . . . . . .  8
     3.1.   ASN.1 Definitions . . . . . . . . . . . . . . . . . . .  9
 4.  The snmp Extension Statement . . . . . . . . . . . . . . . . . 10
     4.1.   The oid Statement . . . . . . . . . . . . . . . . . . . 10
     4.2.   The node Statement. . . . . . . . . . . . . . . . . . . 10
            4.2.1. The node's oid Statement . . . . . . . . . . . . 10
            4.2.2. The node's represents Statement. . . . . . . . . 10
            4.2.3. The node's status Statement. . . . . . . . . . . 11
            4.2.4. The node's description Statement . . . . . . . . 11
            4.2.5. The node's reference Statement . . . . . . . . . 11

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            4.2.6. Usage Examples . . . . . . . . . . . . . . . . . 11
     4.3.   The scalars Statement . . . . . . . . . . . . . . . . . 11
            4.3.1. The scalars' oid Statement . . . . . . . . . . . 12
            4.3.2. The scalars' object Statement  . . . . . . . . . 12
            4.3.3. The scalars' status Statement  . . . . . . . . . 13
            4.3.4. The scalars' description Statement . . . . . . . 14
            4.3.5. The scalars' reference Statement . . . . . . . . 14
            4.3.6. Usage Example. . . . . . . . . . . . . . . . . . 14
     4.4.   The table Statement . . . . . . . . . . . . . . . . . . 14
            4.4.1. The table's oid Statement. . . . . . . . . . . . 15
            4.4.2. Table Indexing Statements. . . . . . . . . . . . 15
            4.4.3. The table's create Statement . . . . . . . . . . 17
            4.4.4. The table's object Statement . . . . . . . . . . 17
            4.4.5. The table's status Statement . . . . . . . . . . 19
            4.4.6. The table's description Statement  . . . . . . . 19
            4.4.7. The table's reference Statement  . . . . . . . . 19
            4.4.8. Usage Example  . . . . . . . . . . . . . . . . . 19
     4.5.   The notification Statement  . . . . . . . . . . . . . . 20
            4.5.1. The notification's oid Statement . . . . . . . . 20
            4.5.2. The notification's signals Statement . . . . . . 20
            4.5.3. The notification's status Statement  . . . . . . 20
            4.5.4. The notification's description Statement . . . . 21
            4.5.5. The notification's reference Statement . . . . . 21
            4.5.6. Usage Example. . . . . . . . . . . . . . . . . . 21
     4.6.   The group Statement . . . . . . . . . . . . . . . . . . 21
            4.6.1. The group's oid Statement  . . . . . . . . . . . 22
            4.6.2. The group's members Statement  . . . . . . . . . 22
            4.6.3. The group's status Statement . . . . . . . . . . 22
            4.6.4. The group's description Statement  . . . . . . . 22
            4.6.5. The group's reference Statement  . . . . . . . . 22
            4.6.6. Usage Example  . . . . . . . . . . . . . . . . . 22
     4.7.   The compliance Statement. . . . . . . . . . . . . . . . 23
            4.7.1. The compliance's oid Statement . . . . . . . . . 23
            4.7.2. The compliance's status Statement  . . . . . . . 23
            4.7.3. The compliance's description Statement . . . . . 23
            4.7.4. The compliance's reference Statement . . . . . . 23
            4.7.5. The compliance's mandatory Statement . . . . . . 24
            4.7.6. The compliance's optional Statement. . . . . . . 24
            4.7.7. The compliance's refine Statement  . . . . . . . 24
            4.7.8. Usage Example  . . . . . . . . . . . . . . . . . 26
 5.  NMRG-SMING-SNMP-EXT  . . . . . . . . . . . . . . . . . . . . . 26
 6.  NMRG-SMING-SNMP  . . . . . . . . . . . . . . . . . . . . . . . 33
 7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 46
 8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 46

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 9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 47
     9.1.   Normative References. . . . . . . . . . . . . . . . . . 47
     9.2.   Informative References. . . . . . . . . . . . . . . . . 47
 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 48
 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 49

1. Introduction

 SMIng (Structure of Management Information, Next Generation)
 [RFC3780] is a protocol-independent data definition language for
 management information.  This memo defines an SMIng language
 extension that specifies the mapping of SMIng definitions of
 identities, classes, and their attributes and events to dedicated
 definitions of nodes, scalar objects, tables and columnar objects,
 and notifications for application in the SNMP management framework.
 Section 2 introduces basics of the SNMP management framework.
 Section 3 defines how SMIng data types are mapped to the data types
 supported by the SNMP protocol.  It introduces some new ASN.1 [ASN1]
 definitions which are used to represent new SMIng base types such as
 floats in the SNMP protocol.
 Section 4 describes the semantics of the SNMP mapping extensions for
 SMIng.  The formal SMIng specification of the extension is provided
 in Section 5.
 Section 6 contains an SMIng module which defines derived types (such
 as RowStatus) that are specific to the SNMP mapping.
 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in [RFC2119].

2. SNMP-Based Internet Management

 The SNMP network management framework [RFC3410] is based on the
 concept of "managed objects".  Managed objects represent real or
 synthesized variables of systems that are to be managed.  Note that
 in spite of these terms this model is not object-oriented.  For
 naming purposes, the managed objects are organized hierarchically in
 an "object identifier tree", where only leaf nodes may represent
 objects.
 Nodes in the object identifier tree may also identify conceptual
 tables, rows of conceptual tables, notifications, groups of objects
 and/or notifications, compliance statements, modules or other
 information.  Each node is identified by an unique "object
 identifier" value which is a sequence of non-negative numbers, named
 "sub-identifiers", where the left-most sub-identifier refers to the

Strauss & Schoenwaelder Experimental [Page 3] RFC 3781 SMIng Mappings to SNMP May 2004

 node next to the root of the tree and the right-most sub-identifier
 refers to the node that is identified by the complete object
 identifier value.  Each sub-identifier has a value between 0 and
 2^32-1 (4294967295).
 The SMIng extensions described in this document are used to map SMIng
 data definitions to SNMP compliant managed objects.  This mapping is
 designed to be readable to computer programs, named MIB compilers, as
 well as to human readers.

2.1. Kinds of Nodes

 Each node in the object identifier tree is of a certain kind and may
 represent management information or not:
 o  Simple nodes, that do not represent management information, but
    may be used for grouping nodes in a subtree.  Those nodes are
    defined by the `node' statement.  This statement can also be used
    to map an SMIng `identity' to a node.
 o  Nodes representing the identity of a module to allow references to
    a module in other objects of type `ObjectIdentifier'.  Those nodes
    are defined by the `snmp' statement,
 o  Scalar objects, which have exactly one object instance and no
    child nodes.  See Section 2.2 for scalar objects' instances.  A
    set of scalar objects is mapped from one or more SMIng classes
    using the `scalars' statement.  The statement block of the
    `scalars' statement contains one `implements' statement for each
    class.  The associated statement blocks in turn contain `object'
    statements that specify the mapping of attributes to scalar
    objects.  Scalar objects MUST not have any child node.
 o  Tables, which represent the root node of a collection of
    information structured in table rows.  Table nodes are defined by
    the `table' statement.  A table object identifier SHOULD not have
    any other child node than the implicitly defined row node (see
    below).
 o  Rows, which belong to a table (that is, row's object identifier
    consists of the table's full object identifier plus a single `1'
    sub-identifier) and represent a sequence of one or more columnar
    objects.  A row node is implicitly defined for each table node.

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 o  Columnar objects, which belong to a row (that is, the columnar
    objects' object identifier consists of the row's full object
    identifier plus a single column-identifying sub-identifier) and
    have zero or more object instances and no child nodes.  They are
    defined as follows: The classes that are implemented by a `table'
    statement are identified by `implements' statements.  The
    statement block of each `implements' statement contains `object'
    statements that specify the mapping of attributes to columnar
    objects of this table.  Columnar objects MUST not have any child
    node.
 o  Notifications, which represent information that is sent by agents
    within unsolicited transmissions.  The `notification' statement is
    used to map an SMIng event to a notification.  A notification's
    object identifier SHOULD not have any child node.
 o  Groups of objects and notifications, which may be used for
    compliance statements.  They are defined using the `group'
    statement.
 o  Compliance statements which define requirements for MIB module
    implementations.  They are defined using the `compliance'
    statement.

2.2. Scalar and Columnar Object Instances

 Instances of managed objects are identified by appending an
 instance-identifier to the object's object identifier.  Scalar
 objects and columnar objects use different ways to construct the
 instance-identifier.
 Scalar objects have exactly one object instance.  It is identified by
 appending a single `0' sub-identifier to the object identifier of the
 scalar object.
 Within tables, different instances of the same columnar object are
 identified by appending a sequence of one or more sub-identifiers to
 the object identifier of the columnar object which consists of the
 values of object instances that unambiguously distinguish a table
 row.  These indexing objects can be columnar objects of the same
 and/or another table, but MUST NOT be scalar objects.  Multiple
 applications of the same object in a single table indexing
 specification are strongly discouraged.

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 The base types of the indexing objects indicate how to form the
 instance-identifier:
 o  integer-valued or enumeration-valued: a single sub-identifier
    taking the integer value (this works only for non-negative
    integers and integers of a size of up to 32 bits),
 o  string-valued, fixed-length strings (or variable-length with
    compact encoding): `n' sub-identifiers, where `n' is the length of
    the string (each octet of the string is encoded in a separate
    sub-identifier),
 o  string-valued, variable-length strings or bits-valued: `n+1' sub-
    identifiers, where `n' is the length of the string or bits
    encoding (the first sub-identifier is `n' itself, following this,
    each octet of the string or bits is encoded in a separate sub-
    identifier),
 o  object identifier-valued (with compact encoding): `n' sub-
    identifiers, where `n' is the number of sub-identifiers in the
    value (each sub-identifier of the value is copied into a separate
    sub-identifier),
 o  object identifier-valued: `n+1' sub-identifiers, where `n' is the
    number of sub-identifiers in the value (the first sub-identifier
    is `n' itself, following this, each sub-identifier in the value is
    copied),
 Note that compact encoding can only be applied to an object having a
 variable-length syntax (e.g., variable-length strings, bits objects
 or object identifier-valued objects).  Further, compact encoding can
 only be associated with the last object in a list of indexing
 objects.  Finally, compact encoding MUST NOT be used on a variable-
 length string object if that string might have a value of zero-
 length.
 Instances identified by use of integer-valued or enumeration-valued
 objects are RECOMMENDED to be numbered starting from one (i.e., not
 from zero).  Integer objects that allow negative values, Unsigned64
 objects, Integer64 objects and floating point objects MUST NOT be
 used for table indexing.
 Objects which are both specified for indexing in a row and also
 columnar objects of the same row are termed auxiliary objects.
 Auxiliary objects SHOULD be non-accessible, except in the following
 circumstances:
 o  within a module originally written to conform to SMIv1, or

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 o  a row must contain at least one columnar object which is not an
    auxiliary object.  In the event that all of a row's columnar
    objects are also specified to be indexing objects then one of them
    MUST be accessible.

2.3. Object Identifier Hierarchy

 The layers of the object identifier tree near the root are well
 defined and organized by standardization bodies.  The first level
 next to the root has three nodes:
    0: ccitt
    1: iso
    2: joint-iso-ccitt
 Note that the renaming of the Commite Consultatif International de
 Telegraphique et Telephonique (CCITT) to International
 Telecommunications Union (ITU) had no consequence on the names used
 in the object identifier tree.
 The root of the subtree administered by the Internet Assigned Numbers
 Authority (IANA) for the Internet is `1.3.6.1' which is assigned with
 the identifier `internet'.  That is, the Internet subtree of object
 identifiers starts with the prefix `1.3.6.1.'.
 Several branches underneath this subtree are used for network
 management:
 The `mgmt' (internet.2) subtree is used to identify "standard"
 definitions.  An information module produced by an IETF working group
 becomes a "standard" information module when the document is first
 approved by the IESG and enters the Internet standards track.
 The `experimental' (internet.3) subtree is used to identify
 experimental definitions being designed by working groups of the IETF
 or IRTF.  If an information module produced by a working group
 becomes a "standard" module, then at the very beginning of its entry
 onto the Internet standards track, the definitions are moved under
 the mgmt subtree.
 The `private' (internet.4) subtree is used to identify definitions
 defined unilaterally.  The `enterprises' (private.1) subtree beneath
 private is used, among other things, to permit providers of
 networking subsystems to register information modules of their
 products.

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 These and some other nodes are defined in the SMIng module NMRG-
 SMING-SNMP-EXT (Section 5).

3. SMIng Data Type Mappings

 SMIng [RFC3780] supports the following set of base types:
 OctetString, Pointer, Integer32, Integer64, Unsigned32, Unsigned64,
 Float32, Float64, Float128, Enumeration, Bits, and ObjectIdentifier.
 The SMIng core module NMRG-SMING ([RFC3780], Appendix A) defines
 additional derived types, among them Counter32 (derived from
 Unsigned32), Counter64 (derived from Unsigned64), TimeTicks32 and
 TimeTicks64 (derived from Unsigned32 and Unsigned64), IpAddress
 (derived from OctetString), and Opaque (derived from OctetString).
 The version 2 of the protocol operations for SNMP document [RFC3416]
 defines the following 9 data types which are distinguished by the
 protocol: INTEGER, OCTET STRING, OBJECT IDENTIFIER, IpAddress,
 Counter32, TimeTicks, Opaque, Counter64, and Unsigned32.
 The SMIng base types and their derived types are mapped to SNMP data
 types according to the following table:
       SMIng Data Type    SNMP Data Type         Comment
       ---------------    -------------------    -------
       OctetString        OCTET STRING           (1)
       Pointer            OBJECT IDENTIFIER
       Integer32          INTEGER
       Integer64          Opaque (Integer64)     (2)
       Unsigned32         Unsigned32             (3)
       Unsigned64         Opaque (Unsigned64)    (2) (4)
       Float32            Opaque (Float32)       (2)
       Float64            Opaque (Float64)       (2)
       Float128           Opaque (Float128)      (2)
       Enumeration        INTEGER
       Bits               OCTET STRING
       ObjectIdentifier   OBJECT IDENTIFIER
       Counter32          Counter32
       Counter64          Counter64
       TimeTicks32        TimeTicks
       TimeTicks64        Opaque (Unsigned64)    (2)
       IpAddress          IpAddress
       Opaque             Opaque
    (1) This mapping includes all types derived from the OctetString
        type except those types derived from the IpAddress and Opaque
        SMIng types defined in the module NMRG-SMING.

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    (2) This type is encoded according to the ASN.1 type with the same
        name defined in Section 3.1.  The resulting BER encoded value
        is then wrapped in an Opaque value.
    (3) This mapping includes all types derived from the Unsigned32
        type except those types derived from the Counter32 and
        TimeTicks32 SMIng types defined in the module NMRG-SMING.
    (4) This mapping includes all types derived from the Unsigned64
        type except those types derived from the Counter64 SMIng type
        defined in the module NMRG-SMING.

3.1. ASN.1 Definitions

 The ASN.1 [ASN1] type definitions below introduce data types which
 are used to map the new SMIng base types into the set of ASN.1 types
 supported by the second version of SNMP protocol operations
 [RFC3416].
 NMRG-SMING-SNMP-MAPPING DEFINITIONS ::= BEGIN
 Integer64 ::=
     [APPLICATION 10]
         IMPLICIT INTEGER (-9223372036854775808..9223372036854775807)
 Unsigned64
     [APPLICATION 11]
         IMPLICIT INTEGER (0..18446744073709551615)
 Float32
     [APPLICATION 12]
         IMPLICIT OCTET STRING (SIZE (4))
 Float64
     [APPLICATION 13]
         IMPLICIT OCTET STRING (SIZE (8))
 Float128
     [APPLICATION 14]
         IMPLICIT OCTET STRING (SIZE (16))
 END
 The definitions of Integer64 and Unsigned64 are consistent with the
 same definitions in the SPPI [RFC3159].  The floating point types
 Float32, Float64 and Float128 support single, double and quadruple

Strauss & Schoenwaelder Experimental [Page 9] RFC 3781 SMIng Mappings to SNMP May 2004

 IEEE floating point values.  The encoding of the values follows the
 "IEEE Standard for Binary Floating-Point Arithmetic" as defined in
 ANSI/IEEE Standard 754-1985 [IEEE754].

4. The snmp Extension Statement

 The `snmp' statement is the main statement of the SNMP mapping
 specification.  It gets one or two arguments: an optional lower-case
 identifier that specifies a node that represents the module's
 identity, and a mandatory statement block that contains all details
 of the SNMP mapping.  All information of an SNMP mapping are mapped
 to an SNMP conformant module of the same name as the containing SMIng
 module.  A single SMIng module must not contain more than one `snmp'
 statement.

4.1. The oid Statement

 The snmp's `oid' statement, which must be present, if the snmp
 statement contains a module identifier and must be absent otherwise,
 gets one argument which specifies the object identifier value that is
 assigned to this module's identity node.

4.2. The node Statement

 The `node' statement is used to name and describe a node in the
 object identifier tree, without associating any class or attribute
 information with this node.  This may be useful to group definitions
 in a subtree of related management information, or to uniquely define
 an SMIng `identity' to be referenced in attributes of type Pointer.
 The `node' statement gets two arguments: a lower-case node identifier
 and a statement block that holds detailed node information in an
 obligatory order.
 See the `nodeStatement' rule of the grammar (Section 5) for the
 formal syntax of the `node' statement.

4.2.1. The node's oid Statement

 The node's `oid' statement, which must be present, gets one argument
 which specifies the object identifier value that is assigned to this
 node.

4.2.2. The node's represents Statement

 The node's `represents' statement, which need not be present, makes
 this node represent an SMIng identity, so that objects of type
 Pointer can reference that identity.  The statement gets one argument
 which specifies the identity name.

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4.2.3 The node's status Statement

 The node's `status' statement, which must be present, gets one
 argument which is used to specify whether this node definition is
 current or historic.  The value `current' means that the definition
 is current and valid.  The value `obsolete' means the definition is
 obsolete and should not be implemented and/or can be removed if
 previously implemented.  While the value `deprecated' also indicates
 an obsolete definition, it permits new/continued implementation in
 order to foster interoperability with older/existing implementations.

4.2.4. The node's description Statement

 The node's `description' statement, which need not be present, gets
 one argument which is used to specify a high-level textual
 description of this node.
 It is RECOMMENDED to include all semantics and purposes of this node.

4.2.5. The node's reference Statement

 The node's `reference' statement, which need not be present, gets one
 argument which is used to specify a textual cross-reference to some
 other document, either another module which defines related
 definitions, or some other document which provides additional
 information relevant to this node.

4.2.6. Usage Examples

 node iso                            { oid 1;     status current; };
 node   org                          { oid iso.3; status current; };
 node     dod                        { oid org.6; status current; };
 node       internet                 { oid dod.1; status current; };
 node   zeroDotZero {
     oid         0.0;
     represents  NMRG-SMING::null;
     status      current;
     description "A null value used for pointers.";
 };

4.3. The scalars Statement

 The `scalars' statement is used to define the mapping of one or more
 classes to a group of SNMP scalar managed objects organized under a
 common parent node.  The `scalars' statement gets two arguments: a

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 lower-case scalar group identifier and a statement block that holds
 detailed mapping information of this scalar group in an obligatory
 order.
 See the `scalarsStatement' rule of the grammar (Section 5) for the
 formal syntax of the `scalars' statement.

4.3.1. The scalars' oid Statement

 The scalars' `oid' statement, which must be present, gets one
 argument which specifies the object identifier value that is assigned
 to the common parent node of this scalar group.

4.3.2. The scalars' object Statement

 The scalars' `object' statement, which must be present at least once,
 makes this scalar group contain a given scalar object.  It gets two
 arguments: the name of the scalar object to be defined and a
 statement block that holds additional detailed information in an
 obligatory order.

4.3.2.1. The object's implements Statement

 The `implements' statement, which must be present, is used to specify
 a single leaf attribute of a class that is implemented by this scalar
 object.  The type of this attribute must be a simple type, i.e., not
 a class.

4.3.2.2. The object's subid Statement

 The `subid' statement, which need not be present, is used to specify
 the sub-identifier that identifies the scalar object within this
 scalar group, i.e., the object identifier of the scalar object is the
 concatenation of the values of this scalar group's oid statement and
 of this subid statement.
 If this statement is omitted, the sub-identifier is the one of the
 previous object statement within this scalar group plus 1.  If the
 containing object statement is the first one within the containing
 scalar group and the subid statement is omitted, the sub-identifier
 is 1.

4.3.2.3. The object's status Statement

 The object's `status' statement, which need not be present, gets one
 argument which is used to specify whether this scalar object
 definition is current or historic.  The value `current' means that

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 the definition is current and valid.  The value `obsolete' means the
 definition is obsolete and should not be implemented and/or can be
 removed if previously implemented.  While the value `deprecated' also
 indicates an obsolete definition, it permits new/continued
 implementation in order to foster interoperability with
 older/existing implementations.
 Scalar objects SHOULD NOT be defined as `current' if the implemented
 attribute definition is `deprecated' or `obsolete'.  Similarly, they
 SHOULD NOT be defined as `deprecated' if the implemented attribute is
 `obsolete'.  Nevertheless, subsequent revisions of used class
 definitions cannot be avoided, but SHOULD be taken into account in
 subsequent revisions of the local module.
 Note that it is RECOMMENDED to omit the status statement which means
 that the status is inherited from the containing scalars statement.
 However, if the status of a scalar object varies from the containing
 scalar group, it has to be expressed explicitly, e.g., if the
 implemented attribute has been deprecated or obsoleted.

4.3.2.4. The object's description Statement

 The object's `description' statement, which need not be present, gets
 one argument which is used to specify a high-level textual
 description of this scalar object.
 Note that in contrast to other definitions this description statement
 is not mandatory and it is RECOMMENDED to omit it, if the object is
 fully described by the description of the implemented attribute.

4.3.2.5. The object's reference Statement

 The object's `reference' statement, which need not be present, gets
 one argument which is used to specify a textual cross-reference to
 some other document, either another module which defines related
 definitions, or some other document which provides additional
 information relevant to this scalar object.
 It is RECOMMENDED to omit this statement, if the object's references
 are fully described by the implemented attribute.

4.3.3. The scalars' status Statement

 The scalars' `status' statement, which must be present, gets one
 argument which is used to specify whether this scalar group
 definition is current or historic.  The value `current' means that
 the definition is current and valid.  The value `obsolete' means the
 definition is obsolete and should not be implemented and/or can be

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 removed if previously implemented.  While the value `deprecated' also
 indicates an obsolete definition, it permits new/continued
 implementation in order to foster interoperability with
 older/existing implementations.

4.3.4. The scalars' description Statement

 The scalars' `description' statement, which must be present, gets one
 argument which is used to specify a high-level textual description of
 this scalar group.
 It is RECOMMENDED to include all semantic definitions necessary for
 the implementation of this scalar group.

4.3.5. The scalars' reference Statement

 The scalars' `reference' statement, which need not be present, gets
 one argument which is used to specify a textual cross-reference to
 some other document, either another module which defines related
 definitions, or some other document which provides additional
 information relevant to this scalars statement.

4.3.6. Usage Example

 scalars ip {
   oid             mib-2.4;
   object ipForwarding { implements Ip.forwarding; };
   object ipDefaultTTL { implements Ip.defaultTTL; };
   // ...
   status          current;
   description
           "This scalar group implements the Ip class.";
 };

4.4. The table Statement

 The `table' statement is used to define the mapping of one or more
 classes to a single SNMP table of columnar managed objects.  The
 `table' statement gets two arguments: a lower-case table identifier
 and a statement block that holds detailed mapping information of this
 table in an obligatory order.
 See the `tableStatement' rule of the grammar (Section 5) for the
 formal syntax of the `table' statement.

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4.4.1. The table's oid Statement

 The table's `oid' statement, which must be present, gets one argument
 which specifies the object identifier value that is assigned to this
 table's node.

4.4.2. Table Indexing Statements

 SNMP table mappings offers five methods to supply table indexing
 information: ordinary tables, table augmentations, sparse table
 augmentations, table expansions, and reordered tables use different
 statements to denote their indexing information.  Each table
 definition must contain exactly one of the following indexing
 statements.

4.4.2.1. The table's index Statement for Table Indexing

 The table's `index' statement, which is used to supply table indexing
 information of base tables, gets one argument that specifies a
 comma-separated list of objects, that are used for table indexing,
 enclosed in parenthesis.
 The elements of the `unique' statement of the implemented class(es)
 and their order should be regarded as a hint for the index elements
 of the table.
 In case of modules that should be compatible on the SNMP protocol
 level to SMIv2 versions of the module, an optional `implied' keyword
 may be added in front of the list to indicate a compact encoding of
 the last object in the list.  See Section 2.2 for details.

4.4.2.2. The table's augments Statement for Table Indexing

 The table's `augments' statement, which is used to supply table
 indexing information of tables that augment a base table, gets one
 argument that specifies the identifier of the table to be augmented.
 Note that a table augmentation cannot itself be augmented.  Anyhow, a
 base table may be augmented by multiple table augmentations.
 A table augmentation makes instances of subordinate columnar objects
 identified according to the index specification of the base table
 corresponding to the table named in the `augments' statement.
 Further, instances of subordinate columnar objects of a table
 augmentation exist according to the same semantics as instances of
 subordinate columnar objects of the base table being augmented.  As
 such, note that creation of a base table row implies the

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 correspondent creation of any table row augmentations.  Table
 augmentations MUST NOT be used in table row creation and deletion
 operations.

4.4.2.3. The table's extends Statement for Table Indexing

 The table's `extends' statement, which is used to supply table
 indexing information of tables that sparsely augment a base table,
 gets one argument that specifies the identifier of the table to be
 sparsely augmented.  Note that a sparse table augmentation cannot
 itself be augmented.  Anyhow, a base table may be augmented by
 multiple table augmentations, sparsely or not.
 A sparse table augmentation makes instances of subordinate columnar
 objects identified, if present, according to the index specification
 of the base table corresponding to the table named in the `extends'
 statement.  Further, instances of subordinate columnar objects of a
 sparse table augmentation exist according to the semantics as
 instances of subordinate columnar objects of the base table and the
 (non-formal) rules that confine the sparse relationship.  As such,
 note that creation of a sparse table row augmentation may be implied
 by the creation of a base table row as well as done by an explicit
 creation.  However, if a base table row gets deleted, any dependent
 sparse table row augmentations get also deleted implicitly.

4.4.2.4. The table's reorders Statement for Table Indexing

 The table's `reorders' statement is used to supply table indexing
 information of tables, that contain exactly the same index objects of
 a base table but in a different order.  It gets at least two
 arguments.  The first one specifies the identifier of the base table.
 The second one specifies a comma-separated list of exactly those
 object identifiers of the base table's `index' statement, but in the
 order to be used in this table.  Note that a reordered table cannot
 itself be reordered.  Anyhow, a base table may be used for multiple
 reordered tables.
 Under some circumstances, an optional `implied' keyword may be added
 in front of the list to indicate a compact encoding of the last
 object in the list.  See Section 2.2 for details.
 Instances of subordinate columnar objects of a reordered table exist
 according to the same semantics as instances of subordinate columnar
 objects of the base table.  As such, note that creation of a base
 table row implies the correspondent creation of any related reordered
 table row.  Reordered tables MUST NOT be used in table row creation
 and deletion operations.

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4.4.2.5. The table's expands Statement for Table Indexing

 The table's `expands' statement is used to supply table indexing
 information of table expansions.  Table expansions use exactly the
 same index objects of another table together with additional indexing
 objects.  Thus, the `expands' statement gets at least two arguments.
 The first one specifies the identifier of the base table.  The second
 one specifies a comma-separated list of the additional object
 identifiers used for indexing.  Note that an expanded table may
 itself be expanded, and base tables may be used for multiple table
 expansions.
 Under some circumstances, an optional `implied' keyword may be added
 in front of the list to indicate a compact encoding of the last
 object in the list.  See Section 2.2 for details.

4.4.3. The table's create Statement

 The table's `create' statement, which need not be present, gets no
 argument.  If the `create' statement is present, table row creation
 (and deletion) is possible.

4.4.4. The table's object Statement

 The table's `object' statement, which must be present at least once,
 makes this table contain a given columnar object.  It gets two
 arguments: the name of the columnar object to be defined and a
 statement block that holds additional detailed information in an
 obligatory order.

4.4.4.1. The object's implements Statement

 The `implements' statement, which must be present, is used to specify
 a single leaf attribute of a class that is implemented by this
 columnar object.  The type of this attribute must be a simple type,
 i.e., not a class.

4.4.4.2. The object's subid Statement

 The `subid' statement, which need not be present, is used to specify
 the sub-identifier that identifies the columnar object within this
 table, i.e., the object identifier of the columnar object is the
 concatenation of the values of this table's oid statement and of this
 subid statement.

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 If this statement is omitted, the sub-identifier is the one of the
 previous object statement within this table plus 1.  If the
 containing object statement is the first one within the containing
 table and the subid statement is omitted, the sub-identifier is 1.

4.4.4.3. The object's status Statement

 The object's `status' statement, which need not be present, gets one
 argument which is used to specify whether this columnar object
 definition is current or historic.  The value `current' means that
 the definition is current and valid.  The value `obsolete' means the
 definition is obsolete and should not be implemented and/or can be
 removed if previously implemented.  While the value `deprecated' also
 indicates an obsolete definition, it permits new/continued
 implementation in order to foster interoperability with
 older/existing implementations.
 Columnar objects SHOULD NOT be defined as `current' if the
 implemented attribute definition is `deprecated' or `obsolete'.
 Similarly, they SHOULD NOT be defined as `deprecated' if the
 implemented attribute is `obsolete'.  Nevertheless, subsequent
 revisions of used class definitions cannot be avoided, but SHOULD be
 taken into account in subsequent revisions of the local module.
 Note that it is RECOMMENDED to omit the status statement which means
 that the status is inherited from the containing table statement.
 However, if the status of a columnar object varies from the
 containing table, it has to be expressed explicitly, e.g., if the
 implemented attribute has been deprecated or obsoleted.

4.4.4.4. The object's description Statement

 The object's `description' statement, which need not be present, gets
 one argument which is used to specify a high-level textual
 description of this columnar object.
 Note that in contrast to other definitions this description statement
 is not mandatory and it is RECOMMENDED to omit it, if the object is
 fully described by the description of the implemented attribute.

4.4.4.5. The object's reference Statement

 The object's `reference' statement, which need not be present, gets
 one argument which is used to specify a textual cross-reference to
 some other document, either another module which defines related
 definitions, or some other document which provides additional
 information relevant to this columnar object.

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 It is RECOMMENDED to omit this statement, if the object's references
 are fully described by the implemented attribute.

4.4.5. The table's status Statement

 The table's `status' statement, which must be present, gets one
 argument which is used to specify whether this table definition is
 current or historic.  The value `current' means that the definition
 is current and valid.  The value `obsolete' means the definition is
 obsolete and should not be implemented and/or can be removed if
 previously implemented.  While the value `deprecated' also indicates
 an obsolete definition, it permits new/continued implementation in
 order to foster interoperability with older/existing implementations.

4.4.6. The table's description Statement

 The table's `description' statement, which must be present, gets one
 argument which is used to specify a high-level textual description of
 this table.
 It is RECOMMENDED to include all semantic definitions necessary for
 the implementation of this table.

4.4.7. The table's reference Statement

 The table's `reference' statement, which need not be present, gets
 one argument which is used to specify a textual cross-reference to
 some other document, either another module which defines related
 definitions, or some other document which provides additional
 information relevant to this table statement.

4.4.8. Usage Example

 table ifTable {
   oid             interfaces.2;
   index           (ifIndex);
   object ifIndex { implements Interface.index;       };
   object ifDescr { implements Interface.description; };
   // ...
   status          current;
   description
           "This table implements the Interface class.";
 };

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4.5. The notification Statement

 The `notification' statement is used to map events defined within
 classes to SNMP notifications.  The `notification' statement gets two
 arguments: a lower-case notification identifier and a statement block
 that holds detailed notification information in an obligatory order.
 See the `notificationStatement' rule of the grammar (Section 5) for
 the formal syntax of the `notification' statement.

4.5.1. The notification's oid Statement

 The notification's `oid' statement, which must be present, gets one
 argument which specifies the object identifier value that is assigned
 to this notification.

4.5.2. The notification's signals Statement

 The notification's `signals' statement, which must be present,
 denotes the event that is signaled by this notification.  The
 statement gets two arguments: the event to be signaled (in the
 qualified form `Class.event') and a statement block that holds
 detailed information on the objects transmitted with this
 notification in an obligatory order.

4.5.2.1. The signals' object Statement

 The signals' `object' statement, which can be present zero, one or
 multiple times, makes a single instance of a class attribute be
 contained in this notification.  It gets one argument: the specific
 class attribute.  The namespace of attributes not specified by
 qualified names is the namespace of the event's class specified in
 the `signals' statement.

4.5.3. The notification's status Statement

 The notification's `status' statement, which must be present, gets
 one argument which is used to specify whether this notification
 definition is current or historic.  The value `current' means that
 the definition is current and valid.  The value `obsolete' means the
 definition is obsolete and should not be implemented and/or can be
 removed if previously implemented.  While the value `deprecated' also
 indicates an obsolete definition, it permits new/continued
 implementation in order to foster interoperability with
 older/existing implementations.

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4.5.4. The notification's description Statement

 The notification's `description' statement, which need not be
 present, gets one argument which is used to specify a high-level
 textual description of this notification.
 It is RECOMMENDED to include all semantics and purposes of this
 notification.

4.5.5. The notification's reference Statement

 The notification's `reference' statement, which need not be present,
 gets one argument which is used to specify a textual cross-reference
 to some other document, either another module which defines related
 definitions, or some other document which provides additional
 information relevant to this notification statement.

4.5.6. Usage Example

 notification linkDown {
     oid         snmpTraps.3;
     signals     Interface.linkDown {
         object      ifIndex;
         object      ifAdminStatus;
         object      ifOperStatus;
     };
     status      current;
     description
           "This notification signals the linkDown event
            of the Interface class.";
 };

4.6. The group Statement

 The `group' statement is used to define a group of arbitrary nodes in
 the object identifier tree.  It gets two arguments: a lower-case
 group identifier and a statement block that holds detailed group
 information in an obligatory order.
 Note that the primary application of groups are compliance
 statements, although they might be referred in other formal or
 informal documents.
 See the `groupStatement' rule of the grammar (Section 5) for the
 formal syntax of the `group' statement.

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4.6.1. The group's oid Statement

 The group's `oid' statement, which must be present, gets one argument
 which specifies the object identifier value that is assigned to this
 group.

4.6.2. The group's members Statement

 The group's `members' statement, which must be present, gets one
 argument which specifies the list of nodes by their identifiers to be
 contained in this group.  The list of nodes has to be comma-separated
 and enclosed in parenthesis.

4.6.3. The group's status Statement

 The group's `status' statement, which must be present, gets one
 argument which is used to specify whether this group definition is
 current or historic.  The value `current' means that the definition
 is current and valid.  The value `obsolete' means the definition is
 obsolete and the group should no longer be used.  While the value
 `deprecated' also indicates an obsolete definition, it permits
 new/continued use of this group.

4.6.4. The group's description Statement

 The group's `description' statement, which must be present, gets one
 argument which is used to specify a high-level textual description of
 this group.  It is RECOMMENDED to include any relation to other
 groups.

4.6.5. The group's reference Statement

 The group's `reference' statement, which need not be present, gets
 one argument which is used to specify a textual cross-reference to
 some other document, either another module which defines related
 groups, or some other document which provides additional information
 relevant to this group.

4.6.6. Usage Example

 The snmpGroup, originally defined in [RFC3418], may be described as
 follows:
 group snmpGroup {
   oid             snmpMIBGroups.8;
   objects         (snmpInPkts, snmpInBadVersions,
                    snmpInASNParseErrs,
                    snmpSilentDrops, snmpProxyDrops,

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                    snmpEnableAuthenTraps);
   status          current;
   description
           "A collection of objects providing basic
            instrumentation and control of an agent.";
 };

4.7. The compliance Statement

 The `compliance' statement is used to define a set of conformance
 requirements, named a `compliance statement'.  It gets two arguments:
 a lower-case compliance identifier and a statement block that holds
 detailed compliance information in an obligatory order.
 See the `complianceStatement' rule of the grammar (Section 5) for the
 formal syntax of the `compliance' statement.

4.7.1. The compliance's oid Statement

 The compliance's `oid' statement, which must be present, gets one
 argument which specifies the object identifier value that is assigned
 to this compliance statement.

4.7.2. The compliance's status Statement

 The compliance's `status' statement, which must be present, gets one
 argument which is used to specify whether this compliance statement
 is current or historic.  The value `current' means that the
 definition is current and valid.  The value `obsolete' means the
 definition is obsolete and no longer specifies a valid definition of
 conformance.  While the value `deprecated' also indicates an obsolete
 definition, it permits new/continued use of the compliance
 specification.

4.7.3. The compliance's description Statement

 The compliance's `description' statement, which must be present, gets
 one argument which is used to specify a high-level textual
 description of this compliance statement.

4.7.4. The compliance's reference Statement

 The compliance's `reference' statement, which need not be present,
 gets one argument which is used to specify a textual cross-reference
 to some other document, either another module which defines related
 compliance statements, or some other document which provides
 additional information relevant to this compliance statement.

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4.7.5. The compliance's mandatory Statement

 The compliance's `mandatory' statement, which need not be present,
 gets one argument which is used to specify a comma-separated list of
 one or more groups (Section 4.6) of objects and/or notifications
 enclosed in parenthesis.  These groups are unconditionally mandatory
 for implementation.
 If an agent claims compliance to a MIB module then it must implement
 each and every object and notification within each group listed in
 the `mandatory' statement(s) of the compliance statement(s) of that
 module.

4.7.6. The compliance's optional Statement

 The compliance's `optional' statement, which need not be present, is
 repeatedly used to name each group which is conditionally mandatory
 for compliance to the compliance statement.  It can also be used to
 name unconditionally optional groups.  A group named in an `optional'
 statement MUST be absent from the correspondent `mandatory'
 statement.  The `optional' statement gets two arguments: a lower-case
 group identifier and a statement block that holds detailed compliance
 information on that group.
 Conditionally mandatory groups include those groups which are
 mandatory only if a particular protocol is implemented, or only if
 another group is implemented.  The `description' statement specifies
 the conditions under which the group is conditionally mandatory.
 A group which is named in neither a `mandatory' statement nor an
 `optional' statement, is unconditionally optional for compliance to
 the module.
 See the `optionalStatement' rule of the grammar (Section 5) for the
 formal syntax of the `optional' statement.

4.7.6.1. The optional's description Statement

 The optional's `description' statement, which must be present, gets
 one argument which is used to specify a high-level textual
 description of the conditions under which this group is conditionally
 mandatory or unconditionally optional.

4.7.7. The compliance's refine Statement

 The compliance's `refine' statement, which need not be present, is
 repeatedly used to specify each object for which compliance has a
 refined requirement with respect to the module definition.  The

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 object must be present in one of the conformance groups named in the
 correspondent `mandatory' or `optional' statements.  The `refine'
 statement gets two arguments: a lower-case identifier of a scalar or
 columnar object and a statement block that holds detailed refinement
 information on that object.
 See the `refineStatement' rule of the grammar (Section 5) for the
 formal syntax of the `refine' statement.

4.7.7.1. The refine's type Statement

 The refine's `type' statement, which need not be present, gets one
 argument that is used to provide a refined type for the correspondent
 object.  Type restrictions may be applied by appending subtyping
 information according to the rules of the base type.  See [RFC3780]
 for SMIng base types and their type restrictions.  In case of
 enumeration or bitset types the order of named numbers is not
 significant.
 Note that if a `type' and a `writetype' statement are both present
 then this type only applies when instances of the correspondent
 object are read.

4.7.7.2. The refine's writetype Statement

 The refine's `writetype' statement, which need not be present, gets
 one argument that is used to provide a refined type for the
 correspondent object, only when instances of that object are written.
 Type restrictions may be applied by appending subtyping information
 according to the rules of the base type.  See [RFC3780] for SMIng
 base types and their type restrictions.  In case of enumeration or
 bitset types the order of named numbers is not significant.

4.7.7.3. The refine's access Statement

 The refine's `access' statement, which need not be present, gets one
 argument that is used to specify the minimal level of access that the
 correspondent object must implement in the sense of its original
 `access' statement.  Hence, the refine's `access' statement MUST NOT
 specify a greater level of access than is specified in the
 correspondent object definition.
 An implementation is compliant if the level of access it provides is
 greater or equal to the minimal level in the refine's `access'
 statement and less or equal to the maximal level in the object's
 `access' statement.

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4.7.7.4. The refine's description Statement

 The refine's `description' statement, which must be present, gets one
 argument which is used to specify a high-level textual description of
 the refined compliance requirement.

4.7.8. Usage Example

 The compliance statement contained in the SNMPv2-MIB [RFC3418],
 converted to SMIng:
    compliance snmpBasicComplianceRev2 {
      oid             snmpMIBCompliances.3;
      status          current;
      description
              "The compliance statement for SNMP entities which
               implement this MIB module.";
      mandatory       (snmpGroup, snmpSetGroup, systemGroup,
                       snmpBasicNotificationsGroup);
      optional snmpCommunityGroup {
        description
              "This group is mandatory for SNMP entities which
               support community-based authentication.";
      };
      optional snmpWarmStartNotificationGroup {
        description
              "This group is mandatory for an SNMP entity which
               supports command responder applications, and is
               able to reinitialize itself such that its
               configuration is unaltered.";
      };
    };

5. NMRG-SMING-SNMP-EXT

 The grammar of the snmp statement (including all its contained
 statements) conforms to the Augmented Backus-Naur Form (ABNF)
 [RFC2234].  It is included in the abnf statement of the snmp SMIng
 extension definition in the NMRG-SMING-SNMP-EXT module below.
 module NMRG-SMING-SNMP-EXT {
    organization    "IRTF Network Management Research Group (NMRG)";
    contact         "IRTF Network Management Research Group (NMRG)
                     http://www.ibr.cs.tu-bs.de/projects/nmrg/

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                     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     "This module defines a SMIng extension to define
                     the mapping of SMIng definitions of class and
                     their attributes and events to SNMP compatible
                     definitions of modules, node, scalars, tables,
                     and notifications, and additional information on
                     module compliances.
                     Copyright (C) The Internet Society (2004).
                     All Rights Reserved.
                     This version of this module is part of
                     RFC 3781, see the RFC itself for full
                     legal notices.";
    revision {
        date        "2003-12-16";
        description "Initial revision, published as RFC 3781.";
    };
    //
    //
    //
    extension snmp {
        status          current;
        description
           "The snmp statement maps SMIng definitions to SNMP
            conformant definitions.";
        abnf "

;; ;; sming-snmp.abnf – Grammar of SNMP mappings in ABNF ;; notation (RFC 2234).

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;; ;; @(#) $Id: sming-snmp.abnf,v 1.14 2003/10/23 19:31:55 strauss Exp $ ;; ;; Copyright (C) The Internet Society (2004). All Rights Reserved. ;;

;; ;; Statement rules. ;;

snmpStatement = snmpKeyword *1(sep lcIdentifier) optsep

                             \"{\" stmtsep
                             *1(oidStatement stmtsep)
                             *(nodeStatement stmtsep)
                             *(scalarsStatement stmtsep)
                             *(tableStatement stmtsep)
                             *(notificationStatement stmtsep)
                             *(groupStatement stmtsep)
                             *(complianceStatement stmtsep)
                             statusStatement stmtsep
                             descriptionStatement stmtsep
                             *1(referenceStatement stmtsep)
                         \"}\" optsep \";\"

nodeStatement = nodeKeyword sep lcIdentifier optsep

                             \"{\" stmtsep
                             oidStatement stmtsep
                             *1(representsStatement stmtsep)
                             statusStatement stmtsep
                             *1(descriptionStatement stmtsep)
                             *1(referenceStatement stmtsep)
                         \"}\" optsep \";\"

representsStatement = representsKeyword sep

                             qucIdentifier optsep \";\"

scalarsStatement = scalarsKeyword sep lcIdentifier optsep

                             \"{\" stmtsep
                             oidStatement stmtsep
                             1*(objectStatement stmtsep)
                             statusStatement stmtsep
                             descriptionStatement stmtsep
                             *1(referenceStatement stmtsep)
                         \"}\" optsep \";\"

tableStatement = tableKeyword sep lcIdentifier optsep

                             \"{\" stmtsep
                             oidStatement stmtsep

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                             anyIndexStatement stmtsep
                             *1(createStatement stmtsep)
                             1*(objectStatement stmtsep)
                             statusStatement stmtsep
                             descriptionStatement stmtsep
                             *1(referenceStatement stmtsep)
                         \"}\" optsep \";\"

objectStatement = objectKeyword sep lcIdentifier optsep

                             \"{\" stmtsep
                             implementsStatement stmtsep
                             *1(subidStatement stmtsep)
                             *1(statusStatement stmtsep)
                             *1(descriptionStatement stmtsep)
                             *1(referenceStatement stmtsep)
                         \"}\" optsep \";\"

implementsStatement = implementsKeyword sep qcattrIdentifier

                             optsep \";\"

notificationStatement = notificationKeyword sep lcIdentifier

                             optsep \"{\" stmtsep
                             oidStatement stmtsep
                             signalsStatement stmtsep
                             statusStatement stmtsep
                             descriptionStatement stmtsep
                             *1(referenceStatement stmtsep)
                         \"}\" optsep \";\"

signalsStatement = signalsKeyword sep qattrIdentifier

                             optsep \"{\" stmtsep
                             *(signalsObjectStatement)
                         \"}\" optsep \";\"

signalsObjectStatement = objectKeyword sep

                             qattrIdentifier optsep \";\"

groupStatement = groupKeyword sep lcIdentifier optsep

                             \"{\" stmtsep
                             oidStatement stmtsep
                             membersStatement stmtsep
                             statusStatement stmtsep
                             descriptionStatement stmtsep
                             *1(referenceStatement stmtsep)
                         \"}\" optsep \";\"

complianceStatement = complianceKeyword sep lcIdentifier optsep

                             \"{\" stmtsep

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                             oidStatement stmtsep
                             statusStatement stmtsep
                             descriptionStatement stmtsep
                             *1(referenceStatement stmtsep)
                             *1(mandatoryStatement stmtsep)
                             *(optionalStatement stmtsep)
                             *(refineStatement stmtsep)
                         \"}\" optsep \";\"

anyIndexStatement = indexStatement /

                         augmentsStatement /
                         reordersStatement /
                         extendsStatement /
                         expandsStatement

indexStatement = indexKeyword *1(sep impliedKeyword) optsep

                             \"(\" optsep qlcIdentifierList
                             optsep \")\" optsep \";\"

augmentsStatement = augmentsKeyword sep qlcIdentifier

                             optsep \";\"

reordersStatement = reordersKeyword sep qlcIdentifier

  • 1(sep impliedKeyword)

optsep \"(\" optsep

                             qlcIdentifierList optsep \")\"
                             optsep \";\"

extendsStatement = extendsKeyword sep qlcIdentifier optsep \";\"

expandsStatement = expandsKeyword sep qlcIdentifier

  • 1(sep impliedKeyword)

optsep \"(\" optsep

                             qlcIdentifierList optsep \")\"
                             optsep \";\"

createStatement = createKeyword optsep \";\"

membersStatement = membersKeyword optsep \"(\" optsep

                             qlcIdentifierList optsep
                             \")\" optsep \";\"

mandatoryStatement = mandatoryKeyword optsep \"(\" optsep

                             qlcIdentifierList optsep
                             \")\" optsep \";\"

optionalStatement = optionalKeyword sep qlcIdentifier optsep

                             \"{\" descriptionStatement stmtsep

Strauss & Schoenwaelder Experimental [Page 30] RFC 3781 SMIng Mappings to SNMP May 2004

                         \"}\" optsep \";\"

refineStatement = refineKeyword sep qlcIdentifier optsep \"{\"

  • 1(typeStatement stmtsep)
  • 1(writetypeStatement stmtsep)
  • 1(accessStatement stmtsep)

descriptionStatement stmtsep

                         \"}\" optsep \";\"

typeStatement = typeKeyword sep

                             (refinedBaseType / refinedType)
                             optsep \";\"

writetypeStatement = writetypeKeyword sep

                             (refinedBaseType / refinedType)
                             optsep \";\"

oidStatement = oidKeyword sep objectIdentifier optsep \";\"

subidStatement = subidKeyword sep subid optsep \";\"

;; ;; Statement keywords. ;;

snmpKeyword = %x73 %x6E %x6D %x70 nodeKeyword = %x6E %x6F %x64 %x65 representsKeyword = %x72 %x65 %x70 %x72 %x65 %x73 %x65 %x6E %x74

                      %x73

scalarsKeyword = %x73 %x63 %x61 %x6C %x61 %x72 %x73 tableKeyword = %x74 %x61 %x62 %x6C %x65 implementsKeyword = %x69 %x6D %x70 %x6C %x65 %x6D %x65 %x6E %x74

                      %x73

subidKeyword = %x73 %x75 %x62 %x69 %x64 objectKeyword = %x6F %x62 %x6A %x65 %x63 %x74 notificationKeyword = %x6E %x6F %x74 %x69 %x66 %x69 %x63 %x61 %x74

                      %x69 %x6F %x6E

signalsKeyword = %x73 %x69 %x67 %x6E %x61 %x6C %x73 oidKeyword = %x6F %x69 %x64 groupKeyword = %x67 %x72 %x6F %x75 %x70 complianceKeyword = %x63 %x6F %x6D %x70 %x6C %x69 %x61 %x6E %x63

                      %x65

impliedKeyword = %x69 %x6D %x70 %x6C %x69 %x65 %x64 indexKeyword = %x69 %x6E %x64 %x65 %x78 augmentsKeyword = %x61 %x75 %x67 %x6D %x65 %x6E %x74 %x73 reordersKeyword = %x72 %x65 %x6F %x72 %x64 %x65 %x72 %x73 extendsKeyword = %x65 %x78 %x74 %x65 %x6E %x64 %x73 expandsKeyword = %x65 %x78 %x70 %x61 %x6E %x64 %x73

Strauss & Schoenwaelder Experimental [Page 31] RFC 3781 SMIng Mappings to SNMP May 2004

createKeyword = %x63 %x72 %x65 %x61 %x74 %x65 membersKeyword = %x6D %x65 %x6D %x62 %x65 %x72 %x73 mandatoryKeyword = %x6D %x61 %x6E %x64 %x61 %x74 %x6F %x72 %x79 optionalKeyword = %x6F %x70 %x74 %x69 %x6F %x6E %x61 %x6C refineKeyword = %x72 %x65 %x66 %x69 %x6E %x65 writetypeKeyword = %x77 %x72 %x69 %x74 %x65 %x74 %x79 %x70 %x65

;; End of ABNF

             ";
   };
   //
   //
   //
   snmp {
       node ccitt                       { oid 0;          };
       node   zeroDotZero {
           oid         0.0;
           description "A null value used for pointers.";
       };
       node iso                         { oid 1;          };
       node   org                       { oid iso.3;      };
       node     dod                     { oid org.6;      };
       node       internet              { oid dod.1;      };
       node         directory           { oid internet.1; };
       node         mgmt                { oid internet.2; };
       node           mib-2             { oid mgmt.1;     };
       node             transmission    { oid mib-2.10;   };
       node         experimental        { oid internet.3; };
       node         private             { oid internet.4; };
       node           enterprises       { oid private.1;  };
       node         security            { oid internet.5; };
       node         snmpV2              { oid internet.6; };
       node           snmpDomains       { oid snmpV2.1;   };
       node           snmpProxys        { oid snmpV2.2;   };
       node           snmpModules       { oid snmpV2.3;   };
       node joint-iso-ccitt             { oid 2;          };
       status          current;
       description
          "This set of nodes defines the core object
           identifier hierarchy";
       reference
          "RFC 2578, Section 2.";

Strauss & Schoenwaelder Experimental [Page 32] RFC 3781 SMIng Mappings to SNMP May 2004

   };

};

6. NMRG-SMING-SNMP

 The module NMRG-SMING-SNMP specified below defines derived types that
 are specific to the SNMP mapping.

module NMRG-SMING-SNMP {

  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 the SMIng SNMP mapping.
                   These definitions are based on RFC 2579 definitions
                   that are specific to the SNMP protocol and its
                   naming system.
                   Copyright (C) The Internet Society (2004).
                   All Rights Reserved.
                   This version of this module is part of
                   RFC 3781, see the RFC itself for full
                   legal notices.";
  revision {
      date        "2003-12-16";
      description "Initial version, published as RFC 3781.";
  };

Strauss & Schoenwaelder Experimental [Page 33] RFC 3781 SMIng Mappings to SNMP May 2004

  typedef TestAndIncr {
      type        Integer32 (0..2147483647);
      description
          "Represents integer-valued information used for atomic
           operations.  When the management protocol is used to
           specify that an object instance having this type 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 SNMP access clause for objects having
           this type has to be `readwrite'.  When an instance of a
           columnar object having this type is created, any value
           may be supplied via the management protocol.
           When the network management portion of the system is re-
           initialized, the value of every object instance having
           this type must either be incremented from its value prior
           to the re-initialization, or (if the value prior to the
           re-initialization is unknown) be set to a
           pseudo-randomly generated value."; };
  typedef AutonomousType {
      type        Pointer;
      description
          "Represents an independently extensible type
           identification value.  It may, for example, indicate a
           particular OID sub-tree with further MIB definitions, or
           define a particular type of protocol or hardware.";
  };
  typedef VariablePointer {
      type        Pointer;
      description
          "A pointer to a specific object instance.  For example,
           sysContact.0 or ifInOctets.3.";
  };
  typedef RowPointer {
      type        Pointer;

Strauss & Schoenwaelder Experimental [Page 34] RFC 3781 SMIng Mappings to SNMP May 2004

      description
          "Represents a pointer to a conceptual row.  The value is
           the name of the instance of the first accessible columnar
           object in the conceptual row.
           For example, ifIndex.3 would point to the 3rd row in the
           ifTable (note that if ifIndex were not-accessible, then
           ifDescr.3 would be used instead).";
  };
  typedef RowStatus {
      type        Enumeration (active(1), notInService(2),
                      notReady(3), createAndGo(4),
                      createAndWait(5), destroy(6));
      description
      "The RowStatus type is used to manage the creation and
       deletion of conceptual rows, and is used as the type for the
       row status column of a conceptual row.
       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 its status automatically set
           to active, making 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 make 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.

Strauss & Schoenwaelder Experimental [Page 35] RFC 3781 SMIng Mappings to SNMP May 2004

       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 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, and an attempt to make it so
       would fail because the agent has insufficient information
       (the state 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
           not be `active' in order for the value of some other
           column of the same conceptual row to be modified.  If
           such a specification is made, affected columns may be
           changed by an SNMP set PDU if the RowStatus would not
           be equal to `active' either immediately before or after
           processing the PDU.  In other words, if the PDU also
           contained a varbind that would change the RowStatus
           value, the column in question may be changed if the
           RowStatus was not equal to `active' as the PDU was
           received, or if the varbind sets the status to a value
           other than 'active'.
       Also note that whenever any elements of a row exist, the
       RowStatus column must also exist.
       To summarize the effect of having a conceptual row with a
       column having a type of RowStatus, consider the following
       state diagram:

Strauss & Schoenwaelder Experimental [Page 36] RFC 3781 SMIng Mappings to SNMP May 2004

                                       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|see 8     ->D|          ->D

————–+————–+———–+————-+————- set status |inconsistent- |inconsist- |noError |noError →C column to | Value| entValue| | notInService | | | |

            |              |     or    |             |      or
            |              |           |             |
            |              |see 3   ->C|          ->C|see 6

————–+————–+———–+————-+————- set status |noError |noError |noError |noError →A column to | | | | or destroy | →A| →A| →A|see 7 ————–+————–+———–+————-+————- set any other |see 4 |noError |noError |see 5 column to some| | | | value | | see 1| →C| →D ————–+————–+———–+————-+————-

       (1) go to 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.

Strauss & Schoenwaelder Experimental [Page 37] RFC 3781 SMIng Mappings to SNMP May 2004

       (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, the return value may be
       either:
           inconsistentName: because the agent does not choose to
           create such an instance when the corresponding
           RowStatus instance does not exist, or
           inconsistentValue: if the supplied value is
           inconsistent with the state of some other MIB object's
           value, or
           noError: because the agent chooses to create the
           instance.
       If noError is returned, then the instance of the status
       column must also be created, and the new state is B or C,
       depending on the information available to the agent.  If
       inconsistentName or inconsistentValue is returned, the row
       remains in state A.
       (5) depending on the MIB definition for the column/table,
       either noError or inconsistentValue may be returned.
       (6) the return value can indicate one of the following
       errors:
           wrongValue: because the agent does not support
           createAndWait, or
           inconsistentValue: because the agent is unable to take
           the row out of service at this time, perhaps because it
           is in use and cannot be de-activated.
       (7) the return value can indicate the following error:
           inconsistentValue: because the agent is unable to
           remove the row at this time, perhaps because it is in
           use and cannot be de-activated.
       NOTE: Other processing of the set request may result in a
       response other than noError being returned, e.g.,
       wrongValue, noCreation, etc.

Strauss & Schoenwaelder Experimental [Page 38] RFC 3781 SMIng Mappings to SNMP May 2004

                        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 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

Strauss & Schoenwaelder Experimental [Page 39] RFC 3781 SMIng Mappings to SNMP May 2004

       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.
       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.

Strauss & Schoenwaelder Experimental [Page 40] RFC 3781 SMIng Mappings to SNMP May 2004

       Once the column requirements have been determined, a
       management protocol set operation is accordingly 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.
                               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

Strauss & Schoenwaelder Experimental [Page 41] RFC 3781 SMIng Mappings to SNMP May 2004

           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.
       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 (and for which the agent allows their values to
           be changed after their creation), 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,

Strauss & Schoenwaelder Experimental [Page 42] RFC 3781 SMIng Mappings to SNMP May 2004

           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 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

Strauss & Schoenwaelder Experimental [Page 43] RFC 3781 SMIng Mappings to SNMP May 2004

           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
       indefinitely.  The agent must detect conceptual rows that
       have been in either state for an abnormally long period of
       time and remove them.  It is the responsibility of the
       DESCRIPTION clause of the status column to indicate what an
       abnormally long period of time would be.  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'.  In
       the absence of such information in the DESCRIPTION clause, it
       is suggested that this period be approximately 5 minutes in
       length.  This removal action applies not only to newly-
       created rows, but also to previously active rows which are
       set to, and left in, the notInService state for a prolonged
       period exceeding that which is considered normal for such a
       conceptual row.
                       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' or `inconsistentValue'.
       Otherwise, the conceptual row is taken out of service, and a
       `noError' response is returned.  It is the responsibility of
       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.";
  };

Strauss & Schoenwaelder Experimental [Page 44] RFC 3781 SMIng Mappings to SNMP May 2004

  typedef StorageType {
      type        Enumeration (other(1), volatile(2),
                      nonVolatile(3), permanent(4),
                      readOnly(5));
      description
          "Describes the memory realization of a conceptual row.  A
           row which is volatile(2) is lost upon reboot.  A row
           which is either nonVolatile(3), permanent(4) or
           readOnly(5), is backed up by stable storage.  A row which
           is permanent(4) can be changed but not deleted.  A row
           which is readOnly(5) cannot be changed nor deleted.
           If the value of an object with this syntax is either
           permanent(4) or readOnly(5), it cannot be modified.
           Conversely, if the value is either other(1), volatile(2)
           or nonVolatile(3), it cannot be modified to be
           permanent(4) or readOnly(5).  (All illegal modifications
           result in a 'wrongValue' error.)
           Every usage of this textual convention is required to
           specify the columnar objects which a permanent(4) row
           must at a minimum allow to be writable.";
  };
  typedef TDomain {
      type        Pointer;
      description
          "Denotes a kind of transport service.
           Some possible values, such as snmpUDPDomain, are defined
           in the SNMPv2-TM MIB module.  Other possible values are
           defined in other MIB modules."
      reference
          "The SNMPv2-TM MIB module is defined in RFC 3417."
  };
  typedef TAddressOrZero {
      type        OctetString (0..255);
      description
          "Denotes a transport service address.
           A TAddress value is always interpreted within the context
           of a TDomain value.  Thus, each definition of a TDomain
           value must be accompanied by a definition of a textual
           convention for use with that TDomain.  Some possible
           textual conventions, such as SnmpUDPAddress for
           snmpUDPDomain, are defined in the SNMPv2-TM MIB module.
           Other possible textual conventions are defined in other

Strauss & Schoenwaelder Experimental [Page 45] RFC 3781 SMIng Mappings to SNMP May 2004

           MIB modules.
           A zero-length TAddress value denotes an unknown transport
           service address."
      reference
          "The SNMPv2-TM MIB module is defined in RFC 3417."
  };
  typedef TAddress {
      type        TAddressOrZero (1..255);
      description
          "Denotes a transport service address.
           This type does not allow a zero-length TAddress value."
  };

};

7. Security Considerations

 This document presents an extension of the SMIng data definition
 language which supports the mapping of SMIng data definitions so that
 they can be used with the SNMP management framework.  The language
 extension and the mapping itself has no security impact on the
 Internet.

8. Acknowledgements

 Since SMIng started as a close successor of SMIv2, some paragraphs
 and phrases are directly taken from the SMIv2 specifications
 [RFC2578], [RFC2579], [RFC2580] written by Jeff Case, Keith
 McCloghrie, David Perkins, Marshall T.  Rose, Juergen Schoenwaelder,
 and Steven L. Waldbusser.
 The authors would like to thank all participants of the 7th NMRG
 meeting held in Schloss Kleinheubach from 6-8 September 2000, which
 was a major step towards the current status of this memo, namely
 Heiko Dassow, David Durham, Keith McCloghrie, and Bert Wijnen.
 Furthermore, several discussions within the SMING Working Group
 reflected experience with SMIv2 and influenced this specification at
 some points.

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9. References

9.1. Normative References

 [RFC3780]  Strauss, F. and J. Schoenwaelder, "SMIng - Next Generation
            Structure of Management Information", RFC 3780, May 2004.
 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC2234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
            Specifications: ABNF", RFC 2234, November 1997.

9.2. Informative References

 [RFC3410]  Case, J., Mundy, R., Partain, D. and B. Stewart,
            "Introduction and Applicability Statements for Internet
            Standard Management Framework", RFC 3410, December 2002.
 [RFC2578]  McCloghrie, K., Perkins, D. and J. Schoenwaelder,
            "Structure of Management Information Version 2 (SMIv2)",
            STD 58, RFC 2578, April 1999.
 [RFC2579]  McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual
            Conventions for SMIv2", STD 59, RFC 2579, April 1999.
 [RFC2580]  McCloghrie, K., Perkins, D. and J. Schoenwaelder,
            "Conformance Statements for SMIv2", STD 60, RFC 2580,
            April 1999.
 [ASN1]     International Organization for Standardization,
            "Specification of Abstract Syntax Notation One (ASN.1)",
            International Standard 8824, December 1987.
 [RFC3159]  McCloghrie, K., Fine, M., Seligson, J., Chan, K., Hahn,
            S., Sahita, R., Smith, A. and F. Reichmeyer, "Structure of
            Policy Provisioning Information (SPPI)", RFC 3159, August
            2001.
 [IEEE754]  Institute of Electrical and Electronics Engineers, "IEEE
            Standard for Binary Floating-Point Arithmetic", ANSI/IEEE
            Standard 754-1985, August 1985.

Strauss & Schoenwaelder Experimental [Page 47] RFC 3781 SMIng Mappings to SNMP May 2004

 [RFC3418]  Presuhn, R., Case, J., McCloghrie, K., Rose, M. and S.
            Waldbusser, "Management Information Base (MIB) for the
            Simple Network Management Protocol (SNMP)", STD 62, RFC
            3418, December 2002.
 [RFC3416]  Presuhn, R., Case, J., McCloghrie, K., Rose, M. and S.
            Waldbusser, "Version 2 of the Protocol Operations for the
            Simple  Network Management Protocol (SNMP)", STD 62, RFC
            3416, December 2002.

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/
 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/

Strauss & Schoenwaelder Experimental [Page 48] RFC 3781 SMIng Mappings to SNMP May 2004

Full Copyright Statement

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Acknowledgement

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Strauss & Schoenwaelder Experimental [Page 49]

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