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



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  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




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  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: [email protected]

                      Juergen Schoenwaelder
                      International University Bremen
                      P.O. Box 750 561
                      28725 Bremen
                      Germany
                      Phone: +49 421 200 3587
                      EMail: [email protected]";

     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



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                          \"}\" 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



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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.";



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    };

};

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: [email protected]

                    Juergen Schoenwaelder
                    International University Bremen
                    P.O. Box 750 561
                    28725 Bremen
                    Germany
                    Phone: +49 421 200 3587
                    EMail: [email protected]";

   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.";
   };




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   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;



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       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:

            - `active', which indicates that the conceptual row is
            available for use by the managed device;

            - `notInService', which indicates that the conceptual
            row exists in the agent, but is unavailable for use by
            the managed device (see NOTE below);

            - `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;

            - `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;

            - `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,

            - `destroy', which is supplied by a management station
            wishing to delete all of the instances associated with
            an existing conceptual row.




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        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:










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                                        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.






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        (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.





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                         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



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        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:

            - a value is returned, indicating that some other
            management station has already created this conceptual
            row.  We return to interaction 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.

            - 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.




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        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







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            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:

            - 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.

            - 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,



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            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.

            - 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



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            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.";
   };




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   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



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            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.









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  [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: [email protected]
  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: [email protected]
  URI:   http://www.eecs.iu-bremen.de/



















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Full Copyright Statement

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