rfc2580.txt

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   response to a management protocol get operation [4] for any object
   within any mandatory conformance group for every possible MIB view,
   or if the agent cannot generate each notification listed in any
   conformance group under the appropriate circumstances, then that
   agent is not a conformant implementation of the MIB module.

5.4.2.  Mapping of the GROUP clause

   The GROUP clause, which need not be present, is repeatedly used to
   name each object and notification group which is conditionally
   mandatory for compliance to the MIB module.  The GROUP clause can
   also be used to name unconditionally optional groups.  A group named
   in a GROUP clause must be absent from the correspondent MANDATORY-
   GROUPS clause.

   Conditionally mandatory groups include those which are mandatory only
   if a particular protocol is implemented, or only if another group is
   implemented.  A GROUP clause's DESCRIPTION specifies the conditions
   under which the group is conditionally mandatory.

   A group which is named in neither a MANDATORY-GROUPS clause nor a
   GROUP clause, is unconditionally optional for compliance to the MIB
   module.



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5.4.3.  Mapping of the OBJECT clause

   The OBJECT clause, which need not be present, is repeatedly used to
   specify each MIB object for which compliance has a refined
   requirement with respect to the MIB module definition.  The MIB
   object must be present in one of the conformance groups named in the
   correspondent MANDATORY-GROUPS clause or GROUP clauses.

   By definition, each object specified in an OBJECT clause follows a
   MODULE clause which names the information module in which that object
   is defined.  Therefore, the use of an IMPORTS statement, to specify
   from where such objects are imported, is redundant and is not
   required in an information module.

5.4.3.1.  Mapping of the SYNTAX clause

   The SYNTAX clause, which need not be present, is used to provide a
   refined SYNTAX for the object named in the correspondent OBJECT
   clause.  Note that if this clause and a WRITE-SYNTAX clause are both
   present, then this clause only applies when instances of the object
   named in the correspondent OBJECT clause are read.

   Consult Section 9 of [2] for more information on refined syntax.

5.4.3.2.  Mapping of the WRITE-SYNTAX clause

   The WRITE-SYNTAX clause, which need not be present, is used to
   provide a refined SYNTAX for the object named in the correspondent
   OBJECT clause when instances of that object are written.

   Consult Section 9 of [2] for more information on refined syntax.

5.4.3.3.  Mapping of the MIN-ACCESS clause

   The MIN-ACCESS clause, which need not be present, is used to define
   the minimal level of access for the object named in the correspondent
   OBJECT clause.  If this clause is absent, the minimal level of access
   is the same as the maximal level specified in the correspondent
   invocation of the OBJECT-TYPE macro.  If present, this clause must
   not specify a greater level of access than is specified in the
   correspondent invocation of the OBJECT-TYPE macro.

   The level of access for certain types of objects is fixed according
   to their syntax definition.  These types include: conceptual tables
   and rows, auxiliary objects, and objects with the syntax of
   Counter32, Counter64 (and possibly, certain types of textual
   conventions).  A MIN-ACCESS clause should not be present for such



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   objects.

   An implementation is compliant if the level of access it provides is
   greater or equal to the minimal level in the MODULE-COMPLIANCE macro
   and less or equal to the maximal level in the OBJECT-TYPE macro.

5.4.4.  Mapping of the DESCRIPTION clause

   The DESCRIPTION clause must be present for each use of the GROUP or
   OBJECT clause.  For an OBJECT clause, it contains a textual
   description of the refined compliance requirement.  For a GROUP
   clause, it contains a textual description of the conditions under
   which the group is conditionally mandatory or unconditionally
   optional.

5.5.  Mapping of the MODULE-COMPLIANCE value

   The value of an invocation of the MODULE-COMPLIANCE macro is an
   OBJECT IDENTIFIER.  As such, this value may be authoritatively used
   when referring to the compliance statement embodied by that
   invocation of the macro.

5.6.  Usage Example

   The compliance statement contained in the (hypothetical) XYZv2-MIB
   might be:

   xyzMIBCompliance MODULE-COMPLIANCE
       STATUS  current
       DESCRIPTION
               "The compliance statement for XYZv2 entities which
               implement the XYZv2 MIB."
      MODULE  -- compliance to the containing MIB module
          MANDATORY-GROUPS { xyzSystemGroup,
                             xyzStatsGroup, xyzTrapGroup,
                             xyzSetGroup,
                             xyzBasicNotificationsGroup }

          GROUP   xyzV1Group
          DESCRIPTION
              "The xyzV1 group is mandatory only for those
               XYZv2 entities which also implement XYZv1."
  ::= { xyzMIBCompliances 1 }

   According to this invocation, to claim alignment with the compliance
   statement named

        { xyzMIBCompliances 1 }


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   a system must implement the XYZv2-MIB's xyzSystemGroup,
   xyzStatsGroup, xyzTrapGroup, and xyzSetGroup object conformance
   groups, as well as the xyzBasicNotificationsGroup notifications
   group.  Furthermore, if the XYZv2 entity also implements XYZv1, then
   it must also support the XYZv1Group group, if compliance is to be
   claimed.












































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6.  Mapping of the AGENT-CAPABILITIES macro

   The AGENT-CAPABILITIES macro is used to convey a set of capabilities
   present in an agent.  It should be noted that the expansion of the
   AGENT-CAPABILITIES macro is something which conceptually happens
   during implementation and not during run-time.

   When a MIB module is written, it is divided into units of conformance
   termed groups.  If an agent claims to implement a group, then it must
   implement each and every object, or each and every notification,
   within that group.  Of course, for whatever reason, an agent might
   implement only a subset of the groups within a MIB module.  In
   addition, the definition of some MIB objects/notifications leave some
   aspects of the definition to the discretion of an implementor.

   Practical experience has demonstrated a need for concisely describing
   the capabilities of an agent with respect to one or more MIB modules.
   The AGENT-CAPABILITIES macro allows an agent implementor to describe
   the precise level of support which an agent claims in regards to a
   MIB group, and to bind that description to the value of an instance
   of sysORID [3].  In particular, some objects may have restricted or
   augmented syntax or access-levels.

   If the AGENT-CAPABILITIES invocation is given to a management-station
   implementor, then that implementor can build management applications
   which optimize themselves when communicating with a particular agent.
   For example, the management-station can maintain a database of these
   invocations.  When a management-station interacts with an agent, it
   retrieves from the agent the values of all instances of sysORID [3].
   Based on this, it consults the database to locate each entry matching
   one of the retrieved values of sysORID.  Using the located entries,
   the management application can now optimize its behavior accordingly.

   Note that the AGENT-CAPABILITIES macro specifies refinements or
   variations with respect to OBJECT-TYPE and NOTIFICATION-TYPE macros
   in MIB modules, NOT with respect to MODULE-COMPLIANCE macros in
   compliance statements.

6.1.  Mapping of the PRODUCT-RELEASE clause

   The PRODUCT-RELEASE clause, which must be present, contains a textual
   description of the product release which includes this set of
   capabilities.

6.2.  Mapping of the STATUS clause

   The STATUS clause, which must be present, indicates whether this



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   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 this
   capabilities statement is no longer in use.

6.3.  Mapping of the DESCRIPTION clause

   The DESCRIPTION clause, which must be present, contains a textual
   description of this set of capabilities.

6.4.  Mapping of the REFERENCE clause

   The REFERENCE clause, which need not be present, contains a textual
   cross-reference to some other document, either another information
   module which defines a related assignment, or some other document
   which provides additional information relevant to this definition.

6.5.  Mapping of the SUPPORTS clause

   The SUPPORTS clause, which need not be present, is repeatedly used to
   name each MIB module for which the agent claims a complete or partial
   implementation.  Each MIB module is named by its module name, and
   optionally, by its associated OBJECT IDENTIFIER (as registered by the
   MODULE-IDENTITY macro, see [2]) as well.

6.5.1.  Mapping of the INCLUDES clause

   The INCLUDES clause, which must follow each and every use of the
   SUPPORTS clause, is used to name each MIB group associated with the
   SUPPORTS clause, which the agent claims to implement.

6.5.2.  Mapping of the VARIATION clause

   The VARIATION clause, which need not be present, is repeatedly used
   to name each object or notification which the agent implements in
   some variant or refined fashion with respect to the correspondent
   invocation of the OBJECT-TYPE or NOTIFICATION-TYPE macro.

   Note that the variation concept is meant for generic implementation
   restrictions, e.g., if the variation for an object depends on the
   values of other objects, then this should be noted in the appropriate
   DESCRIPTION clause.

   By definition, each object specified in a VARIATION clause follows a
   SUPPORTS clause which names the information module in which that
   object is defined.  Therefore, the use of an IMPORTS statement, to
   specify from where such objects are imported, is redundant and is not


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   required in an information module.

6.5.2.1.  Mapping of the SYNTAX clause

   The SYNTAX clause, which need not be present, is used to provide a
   refined SYNTAX for the object named in the correspondent VARIATION
   clause.  Note that if this clause and a WRITE-SYNTAX clause are both
   present, then this clause only applies when instances of the object
   named in the correspondent VARIATION clause are read.

   Consult Section 9 of [2] for more information on refined syntax.

   Note that for enumerated INTEGERs and for the BITS construct, the
   changes allowed when updating a MIB module include the addition of
   enumerations and/or changing the labels of existing enumerations (see
   Section 10.2 of [2]).  This type of change can cause problems for an
   AGENT-CAPABILITIES macro written against the old revision of a MIB
   module.  One way to avoid such problems is to explicitly list all
   objects having an enumerated syntax in a VARIATION clause, even when
   all enumerations are currently supported.

6.5.2.2.  Mapping of the WRITE-SYNTAX clause

   The WRITE-SYNTAX clause, which need not be present, is used to
   provide a refined SYNTAX for the object named in the correspondent
   VARIATION clause when instances of that object are written.

   Consult Section 9 of [2] for more information on refined syntax.

6.5.2.3.  Mapping of the ACCESS clause

   The ACCESS clause, which need not be present, is used to indicate the
   agent provides less than the maximal level of access to the object or
   notification named in the correspondent VARIATION clause.

   The only value applicable to notifications is "not-implemented".

   The value "not-implemented" indicates the agent does not implement
   the object or notification, and in the ordering of possible values is
   equivalent to "not-accessible".

   The value "write-only" is provided solely for backward compatibility,
   and shall not be used for newly-defined object types.  In the
   ordering of possible values, "write-only" is less than "not-
   accessible".





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6.5.2.4.  Mapping of the CREATION-REQUIRES clause

   The CREATION-REQUIRES clause, which need not be present, is used to
   name the columnar objects of a conceptual row to which values must be
   explicitly assigned, by a management protocol set operation, before
   the agent will allow the instance of the status column of that row to
   be set to `active'.  (Consult the definition of RowStatus [5].)

   If the conceptual row does not have a status column (i.e., the
   objects corresponding to the conceptual table were defined using the
   mechanisms in [6,7]), then the CREATION-REQUIRES clause, which need
   not be present, is used to name the columnar objects of a conceptual
   row to which values must be explicitly assigned, by a management
   protocol set operation, before the agent will create new instances of
   objects in that row.

   This clause must not be present unless the object named in the
   correspondent VARIATION clause is a conceptual row, i.e., has a
   syntax which resolves to a SEQUENCE containing columnar objects.  The
   objects named in the value of this clause usually will refer to
   columnar objects in that row.  However, objects unrelated to the
   conceptual row may also be specified.

   All objects which are named in the CREATION-REQUIRES clause for a
   conceptual row, and which are columnar objects of that row, must have
   an access level of "read-create".

6.5.2.5.  Mapping of the DEFVAL clause

   The DEFVAL clause, which need not be present, is used to provide a
   alternate DEFVAL value for the object named in the correspondent
   VARIATION clause.  The semantics of this value are identical to those
   of the OBJECT-TYPE macro's DEFVAL clause.

6.5.2.6.  Mapping of the DESCRIPTION clause

   The DESCRIPTION clause, which must be present for each use of the
   VARIATION clause, contains a textual description of the variant or
   refined implementation of the object or notification.