Internet Info 1993/Internet Info CD-ROM (Walnut Creek) (1993).iso/inet/rfc/rfc1095

Text File | 1991-04-20 | 150.1 KB | 3,755 lines

Network Working Group                                         U. Warrier
Request for Comments: 1095                            Unisys Corporation
                                                                L. Besaw
                                                         Hewlett-Packard
                                                              April 1989


  The Common Management Information Services and Protocol over TCP/IP
                                 (CMOT)

                        Table of Contents

1. Status of this Memo ............................................    3
2. Introduction ...................................................    4
Part I: Concepts and Models .......................................    7
3. The OSI Management Framework ...................................    7
3.1. Architectural Overview .......................................    7
3.2. Management Models ............................................    8
3.2.1. The Organizational Model ...................................    8
3.2.2. The Functional Model .......................................    8
3.2.3. The Information Model ......................................    9
3.3. ISO Application Protocols ....................................    9
3.3.1. ACSE .......................................................   10
3.3.2. ROSE .......................................................   10
3.3.3. CMISE ......................................................   10
3.3.3.1. Management Association Services ..........................   11
3.3.3.2. Management Notification Services .........................   12
3.3.3.3. Management Operation Services ............................   12
4. The CMOT Architecture ..........................................   13
4.1. Management Models ............................................   13
4.1.1. The Organizational Model ...................................   13
4.1.2. The Functional Model .......................................   14
4.1.3. The Information Model ......................................   14
4.2. Protocol Architecture ........................................   14
4.2.1 The Lightweight Presentation Layer ..........................   15
4.2.2 The Quality of Transport Service ............................   16
4.3. Proxy Management .............................................   17
4.4. Directory Service ............................................   18
5. Management Information .........................................   18
5.1. The Structure of Management Information ......................   19
5.1.1. The ISO SMI ................................................   19
5.1.1.1. Managed Objects and Attributes ...........................   19
5.1.1.2. Management Information Hierarchies .......................   20
5.1.1.2.1 The Registration Hierarchy ..............................   20
5.1.1.2.2. The Containment Hierarchy ..............................   20
5.1.1.2.3. The Inheritance Hierarchy ..............................   22
5.1.2. The Internet SMI ...........................................   22
5.2. The Management Information Base ..............................   23



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5.3. An Interpretation of the Internet SMI ........................   24
5.3.1. Object Class and Attributes ................................   25
5.3.1.1. Object Class .............................................   25
5.3.1.2. Attribute Identifier .....................................   26
5.3.2. Management Information Hierarchies .........................   26
5.3.2.1. The Registration Hierarchy ...............................   26
5.3.2.2. The Containment Hierarchy ................................   26
5.3.2.3. The Inheritance Hierarchy ................................   28
5.4. Scoping, Filtering, and Synchronization ......................   28
5.4.1. Scoping ....................................................   28
5.4.2. Filtering ..................................................   29
5.4.3. Synchronization ............................................   29
5.4.4. Linked Replies .............................................   29
5.5. Accessing Tables .............................................   29
5.5.1. Accessing Whole Tables .....................................   30
5.5.2. Accessing Table Entries ....................................   30
Part II: Protocol Agreements ......................................   32
6. CMOT Protocol Overview .........................................   32
6.1. The CMOT Protocol Suite ......................................   32
6.2. Conformance Requirements .....................................   33
6.3. Abstract Syntax Notation .....................................   33
7. Common Management Information Service Element ..................   34
7.1. CMIS Services ................................................   34
7.1.1. CMIS Services Overview .....................................   34
7.1.2. Functional Units ...........................................   34
7.1.3. Functional Unit Groups .....................................   36
7.1.4. M-INITIALISE Parameters ....................................   37
7.1.4.1. Functional Units .........................................   37
7.1.4.2. User Information .........................................   39
7.1.4.3. Access Control ...........................................   39
7.2. Supporting Services ..........................................   39
7.3. CMIP Agreements ..............................................   39
7.3.1. Invoke Identifier ..........................................   39
7.3.2. Object Class ...............................................   40
7.3.3. Object Instance ............................................   40
7.3.4. Access Control .............................................   41
7.3.5. Synchronization ............................................   41
7.3.6. Scope ......................................................   41
7.3.7. Filter .....................................................   41
7.3.8. Attribute Identifier .......................................   42
7.3.9. Event Type Identifier ......................................   42
7.3.10. Action Type Identifier ....................................   42
7.3.11. Time Fields ...............................................   43
7.3.12. Response PDUs .............................................   43
7.3.13. Error PDUs ................................................   43
8. Association Control Service Element ............................   43
8.1. ACSE Services ................................................   44
8.2. Supporting Services ..........................................   44



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8.3. ACSE Protocol ................................................   45
8.3.1. Application Context Name ...................................   45
8.3.2. User Information ...........................................   45
8.3.3. Presentation Service Parameters ............................   46
9. Remote Operations Service Element ..............................   46
9.1. ROSE Services ................................................   46
9.2. Supporting Services ..........................................   47
9.3. ROSE Protocol ................................................   47
9.3.1. Operation Class ............................................   47
9.3.2. Priority ...................................................   48
10. Lightweight Presentation ......................................   48
10.1. Lightweight Presentation Services ...........................   48
10.2. Supporting Services .........................................   48
10.3. Lightweight Presentation Protocol ...........................   49
11. Acknowledgements ..............................................   49
12. References ....................................................   49
Appendix A - The CMOT Group .......................................   52
Appendix B - Management Information Summary .......................   53
Appendix C - Sample Protocol Exchanges ............................   60

1.  Status of this Memo

   This memo defines a network management architecture that uses the
   International Organization for Standardization's (ISO) Common
   Management Information Services/Common Management Information
   Protocol (CMIS/CMIP) in a TCP/IP environment.  This architecture
   provides a means by which control and monitoring information can be
   exchanged between a manager and a remote network element.  In
   particular, this memo defines the means for implementing the Draft
   International Standard (DIS) version of CMIS/CMIP on top of Internet
   transport protocols for the purpose of carrying management
   information defined in the Internet-standard management information
   base.  DIS CMIS/CMIP is suitable for deployment in TCP/IP networks
   while CMIS/CMIP moves toward becoming an International Standard.
   Together with the relevant ISO standards and the companion RFCs that
   describe the initial structure of management information and
   management information base, these documents provide the basis for a
   comprehensive architecture and system for managing TCP/IP-based
   internets, and in particular the Internet.

   The Internet Activities Board (IAB) has designated two different
   network management protocols with the same status of "Draft Standard"
   and "Recommended".

   The two protocols are the Common Management Information Services and
   Protocol over TCP/IP (CMOT) (this memo) and the Simple Network
   Management Protocol (SNMP) [4].




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   The IAB intends each of these two protocols to receive the attention
   of implementers and experimenters.  The IAB seeks reports of
   experience with these two protocols from system builders and users.

   By this action, the IAB recommends that all IP and TCP
   implementations be network manageable (e.g., implement the Internet
   MIB [3], and that implementations that are network manageable are
   expected to adopt and implement at least one of these two Internet
   Draft Standards.

   Distribution of this memo is unlimited.

2.  Introduction

   As reported in RFC 1052, "IAB Recommendations for the Development of
   Internet Network Management Standards" [1], the Internet Activities
   Board (IAB) has directed the Internet Engineering Task Force (IETF)
   to coordinate the work of three working groups in the area of network
   management. First, the MIB working group was charged with the
   specification and definition of elements to be included in the
   Management Information Base (MIB).  Second, the SNMP working group
   was charged with defining the modifications to the Simple Network
   Management Protocol (SNMP) necessary to accommodate the short-term
   needs of the network vendor and operations communities.  Third, the
   Netman working group was directed to meet the longer-term needs of
   the Internet community by developing a network management system
   based on ISO CMIS/CMIP.  Both the Netman working group and the SNMP
   working group were directed to align their work with the output of
   the MIB working group in order to ensure compatibility of management
   information between the short-term and long-term approaches to the
   management of TCP/IP-based internets.  This will enable a smooth
   transition from the short-term protocol (SNMP) to the long-term
   protocol (CMIP).

   The MIB working group has produced two memos.  RFC 1065 [2] defines
   the Structure of Management Information (SMI) that is necessary for
   naming and defining managed objects in the MIB.  RFC 1066 [3] defines
   the list of managed objects contained in the initial TCP/IP MIB.  The
   SNMP working group has produced a memo [4] giving the protocol
   specification for SNMP and providing the SNMP protocol-specific
   interpretation of the Internet-standard MIB defined in RFC 1066.

   This memo is the output of the Netman working group.  As directed by
   the IAB in RFC 1052, it addresses the need for a long-term network
   management system based on ISO CMIS/CMIP.  The network management
   approach of using ISO protocols in a TCP/IP environment to manage
   TCP/IP networks can be described as "CMIP Over TCP/IP" (CMOT).  This
   memo specifies the CMOT architecture and the protocol agreements



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   necessary to implement CMIP and accompanying ISO protocols over the
   TCP and UDP transport protocols.  In addition, this memo provides an
   interpretation of RFC 1066 that makes it possible to use CMIP to
   convey management information defined in the Internet-standard MIB.

   There is widespread vendor support for the CMOT approach to network
   management.  This is amply shown by the Netman demonstration of
   prototype CMOT implementations at the Interop '88 TCP/IP
   Interoperability Conference.  The demonstration also showed the
   feasibility and power of the CMIS/CMIP framework for multivendor
   network management.  Now that CMIS/CMIP has been voted a Draft
   International Standard (DIS), many vendors feel that the ISO standard
   has become a stable basis for product development.  The clear need to
   standardize this development has led to the present profile of CMIP.
   It is expected that this profile will not change while the ISO
   standard moves from DIS status to International Standard (IS) status.
   If, however, the standard does change unexpectedly, the Netman
   working group will review such changes for appropriate action.

   Another rationale for the CMOT approach is that it will facilitate
   the early use of ISO network management standards in large
   operational networks.  This will make it possible for the Internet
   community to make valuable recommendations to ISO in the language of
   OSI management based on actual experience with the use and
   implementation of these standards.  There is continuing network
   management standards development work in ISO where such contributions
   would be valuable.

   The CMOT architecture is based on the Open Systems Interconnection
   (OSI) management framework and models developed by ISO.  This memo
   contains a set of protocol agreements for implementing a network
   management system based on this architecture. The protocol agreement
   sections of this memo must be read in conjunction with ISO and
   Internet documents defining specific protocol standards.  Documents
   defining the following ISO standards are required for the
   implementor: Abstract Syntax Notation One (ASN.1) [5, 6], Association
   Control (ACSE) [7, 8], Remote Operations (ROSE) [9, 10], Common
   Management Information Services (CMIS) [11], and Common Management
   Information Protocol (CMIP) [12].  RFC 1085 [13] is required for the
   specification of a lightweight presentation layer protocol used in
   this profile.  In addition, RFC 1065 [2] and RFC 1066 [3] are
   required for a definition of the initial SMI and MIB to be used with
   the CMOT management system.

   This memo is divided into two main parts.  The first part presents
   concepts and models; the second part contains the protocol agreements
   necessary for implementation of the CMOT network management system.
   The first part of the memo is divided into three sections: section 3



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   contains tutorial information on the OSI management framework;
   section 4 defines the basic CMOT approach; and section 5 discusses
   the area of management information and specifies how the abstract
   management information defined in the Internet-standard SMI and MIB
   map into CMIP.  The second part of this memo is divided into sections
   for each of the protocols for which implementors' agreements are
   needed: CMISE, ACSE, ROSE, and the lightweight presentation protocol.
   The protocol profile defined in this part draws on the technical work
   of the OSI Network Management Forum [14] and the Network Management
   Special Interest Group (NMSIG) of the National Institute of Standards
   and Technology (NIST) (formerly the National Bureau of Standards).
   Wherever possible, an attempt has been made to remain consistent with
   the protocol agreements reached by these groups.






































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                        Part I: Concepts and Models

3.  The OSI Management Framework

   The OSI management framework [15] presents the basic concepts and
   models required for developing network management standards.  OSI
   management provides the ability to monitor and control network
   resources, which are represented as "managed objects." The following
   elements are essential for the description of a network management
   architecture and the standardization of a network management system:
   a model or set of models for understanding management; a common
   structure of management information for registering, identifying, and
   defining managed objects; detailed specifications of the managed
   objects; and a set of services and related protocols for performing
   remote management operations.

3.1.  Architectural Overview

   The basic concepts underlying OSI network management are quite simple
   [16].  There reside application processes called "managers" on
   managing systems (or management stations).  There reside application
   processes called "agents" on managed systems (or network elements
   being managed).  Network management occurs when managers and agents
   conspire (via protocols and a shared conceptual schema) to exchange
   monitoring and control information useful to the management of a
   network and its components.  The terms "manager" and "agent" are also
   used in a loose and popular sense to refer to the managing and
   managed system, respectively.

   The shared conceptual schema mentioned above is a priori knowledge
   about "managed objects" concerning which information is exchanged.
   Managed objects are system and networking resources (e.g., a modem, a
   protocol entity, an IP routing table, a TCP connection) that are
   subject to management. Management activities are effected through the
   manipulation of managed objects in the managed systems.  Using the
   management services and protocol, the manager can direct the agent to
   perform an operation on a managed object for which it is responsible.
   Such operations might be to return certain values associated with a
   managed object (read a variable), to change certain values associated
   with a managed object (set a variable), or perform an action (such as
   self-test) on the managed object.  In addition, the agent may also
   forward notifications generated asynchronously by managed objects to
   the manager (events or traps).

   The terms "manager" and "agent" are used to denote the asymmetric
   relationship between management application processes in which the
   manager plays the superior role and the agent plays the subordinate.




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   However, the specification of the management protocol (CMIP) defines
   a peer protocol relationship that makes no assumptions concerning
   which end opens or closes a connection, or the direction of
   management data transfer.  The protocol mechanisms provided are fully
   symmetric between the manager and the agent; CMIS operations can
   originate at either the manager or agent, as far as the protocol is
   concerned.  This allows the possibility of symmetric as well as
   asymmetric relationships between management processes.  Most devices
   will contain management applications that can only assume the agent
   role.  Applications on managing systems, however, may well be able to
   play both roles at the same time.  This makes possible "manager to
   manager" communication and the ability of one manager to manage
   another.

3.2.  Management Models

   Network management may be modeled in different ways.  Three models
   are typically used to describe OSI management [17, 18].  An
   organizational model describes ways in which management can be
   administratively distributed.  The functional model describes the
   management functions and their relationships.  The information model
   provides guidelines for describing managed objects and their
   associated management information.

3.2.1.  The Organizational Model

   The organizational model introduces the concept of a management
   "domain." A domain is an administrative partition of a network or
   internet for the purpose of network management.  Domains may be
   useful for reasons of scale, security, or administrative autonomy.
   Each domain may have one or more managers monitoring and controlling
   agents in that domain.  In addition, both managers and agents may
   belong to more than one management domain.  Domains allow the
   construction of both strict hierarchical and fully cooperative and
   distributed network management systems.

3.2.2.  The Functional Model

   The OSI Management Framework [15] defines five facilities or
   functional areas to meet specific management needs. This has proved
   to be a helpful way of partitioning the network management problem
   from an application point of view.  These facilities have come to be
   known as the Specific Management Functional Areas (SMFAs): fault
   management, configuration management, performance management,
   accounting management, and security management.  Fault management
   provides the ability to detect, isolate, and correct network
   problems.  Configuration management enables network managers to
   change the configuration of remote network elements.  Performance



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   management provides the facilities to monitor and evaluate the
   performance of the network.  Accounting management makes it possible
   to charge users for network resources used and to limit the use of
   those resources.  Finally, security management is concerned with
   managing access control, authentication, encryption, key management,
   and so on.

3.2.3.  The Information Model

   The OSI Management Framework considers all information relevant to
   network management to reside in a Management Information Base (MIB),
   which is a "conceptual repository of management information."
   Information within a system that can be referenced by the management
   protocol (CMIP) is considered to be part of the MIB.  Conventions for
   describing and uniquely identifying the MIB information allow
   specific MIB information to be referenced and operated on by the
   management protocol.  These conventions are called the Structure of
   Management Information (SMI).  The information model is described
   more fully in section 5.

3.3.  ISO Application Protocols

   The following ISO application services and protocols are necessary
   for doing network management using the OSI framework: ACSE, ROSE, and
   CMIS/CMIP.  All three of these protocols are defined using ASN.1 [5].
   The ASN.1 modules defining each of these protocols are found in the
   relevant standards documents.  The encoding rules for ASN.1 [6]
   provide a machine-independent network representation for data.

   A brief overview of the terminology associated with the OSI
   application layer structure is presented here.  A complete treatment
   of the subject can be found in the OSI Application Layer Structure
   document [22].

   In the OSI environment, communication between "application processes"
   is modeled by communication between application entities.  An
   "application entity" represents the communication functions of an
   application process.  There may be multiple sets of OSI communication
   functions in an application process, so a single application process
   may be represented by multiple application entities.  However, each
   application entity represents a single application process.  An
   application entity contains a set of communication capabilities
   called "application service elements." An application service element
   is a coherent set of integrated functions.  These application service
   elements may be used independently or in combination.  Examples of
   application service elements are X.400, FTAM, ACSE, ROSE, and CMISE.

   When communication is required between two application entities, one



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   or more "application associations" are established between them.
   Such an association can be viewed as a connection at the level of the
   application layer.  An "application context" defines the set of
   application service elements which may be invoked by the user of an
   application association.  The application context may prescribe one
   or more application service elements.

   Generally, an "application layer protocol" is realized by the use of
   the functionality of a number of application service elements.  This
   functionality is provided by the specification of a set of
   application protocol data units (APDUs) and the procedures governing
   their use.  In general, the operation of an application layer
   protocol may require the combination of APDUs from different
   application service elements.  The application entity makes direct
   use of presentation context identifiers for the specification and
   identification of APDUs.

3.3.1.  ACSE

   The Association Control Service Element (ACSE) is used to establish
   and release associations between application entities. Before any
   management operations can be performed using CMIP, it is necessary
   for the two application entities involved to form an association.
   Either the manager or the agent can initiate association
   establishment.  ACSE allows the manager and agent to exchange
   application entity titles for the purpose of identification and
   application context names to establish an application context. As
   stated above, an application context defines what service elements
   (for instance, ROSE and CMISE) may be used over the association.
   After the association is established, ACSE is not used again until
   the association is released by the manager or agent.

3.3.2.  ROSE

   The Remote Operation Service Element (ROSE) is the ISO equivalent of
   remote procedure call.  ROSE allows the invocation of an operation to
   be performed on a remote system.  The Remote Operation protocol
   contains an invoke identifier for correlating requests and responses,
   an operation code, and an argument field for parameters specific to
   the operation.  ROSE can only be invoked once an application
   association has been established.  CMIP uses the transaction-oriented
   services provided by ROSE for all its requests and responses.  CMIP
   also uses the error response facilities provided by ROSE.

3.3.3.  CMISE

   The Common Management Information Service Element (CMISE) is the
   service element that provides the basic management services.  The



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   CMISE is a user of both ROSE and ACSE.  The CMISE provides both
   confirmed and unconfirmed services for reporting events and
   retrieving and manipulating management data. These services are used
   by manager and agent application entities to exchange management
   information.  Table 1 provides a list of the CMISE services.  In
   addition, the CMISE also provides the ability to issue a series of
   (multiple) linked replies in response to a single request.


           +-----------------+-------------------------+
           |    Service      |     Type                |
           +-----------------+-------------------------+
           |  M-INITIALISE   | confirmed               |
           |  M-TERMINATE    | confirmed               |
           |  M-ABORT        | non-confirmed           |
           |  M-EVENT-REPORT | confirmed/non-confirmed |
           |  M-GET          | confirmed               |
           |  M-SET          | confirmed/non-confirmed |
           |  M-ACTION       | confirmed/non-confirmed |
           |  M-CREATE       | confirmed               |
           |  M-DELETE       | confirmed               |
           +-----------------+-------------------------+

                Table 1.  CMISE Service Summary


   CMIS services can be divided into two main classes: management
   association services and information transfer services.  Furthermore,
   there are two types of information transfer services: management
   notification services and management operation services.  In addition
   to the other CMIS services, the CMISE provides facilities that enable
   multiple responses to confirmed operations to be linked to the
   operation by the use of a linked identification parameter.

3.3.3.1.  Management Association Services

   CMIS provides services for the establishment and release of
   application associations.  These services control the establishment
   and normal and abnormal release of a management association. These
   services are simply pass-throughs to ACSE.

   The M-INITIALISE service is invoked by a CMISE-service-user to
   establish an association with a remote CMISE-service-user for the
   purpose of exchanging management information. A reply is expected.
   (A CMISE-service-user is that part of an application process that
   makes use of the CMISE.)

   The M-TERMINATE service is invoked by a CMISE-service-user to release



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   an association with a remote CMISE-service-user in an orderly manner.
   A reply is expected.

   The M-ABORT service is invoked by a CMISE-service-user or a CMISE-
   service-provider to release an association with a remote CMISE-
   service-user in an abrupt manner.

3.3.3.2.  Management Notification Services

   The definition of notification and the consequent behavior of the
   communicating entities is dependent upon the specification of the
   managed object which generated the notification and is outside the
   scope of CMIS.  CMIS provides the following service to convey
   management information applicable to notifications.

   The M-EVENT-REPORT service is invoked by a CMISE-service-user to
   report an event about a managed object to a remote CMISE-service-
   user.  The service may be requested in a confirmed or a non-confirmed
   mode.  In the confirmed mode, a reply is expected.

3.3.3.3.  Management Operation Services

   The definition of the operation and the consequent behavior of the
   communicating entities is dependent upon the specification of the
   managed object at which the operation is directed and is outside the
   scope of CMIS.  However, certain operations are used frequently
   within the scope of management and CMIS provides the following
   definitions of the common services that may be used to convey
   management information applicable to the operations.

   The M-GET service is invoked by a CMISE-service-user to request the
   retrieval of management information from a remote CMISE-service-user.
   The service may only be requested in a confirmed mode.  A reply is
   expected.

   The M-SET service is invoked by a CMISE-service-user to request the
   modification of management information by a remote CMISE-service-
   user.  The service may be requested in a confirmed or a non-confirmed
   mode.  In the confirmed mode, a reply is expected.

   The M-ACTION service is invoked by a CMISE-service-user to request a
   remote CMISE-service-user to perform an action.  The service may be
   requested in a confirmed or a non-confirmed mode.  In the confirmed
    mode, a reply is expected.

   The M-CREATE service is invoked by a CMISE-service-user to request a
   remote CMISE-service-user to create another instance of a managed
   object.  The service may only be requested in a confirmed mode.  A



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   reply is expected.

   The M-DELETE service is invoked by a CMISE-service-user to request a
   remote CMISE-service-user to delete an instance of a managed object.
   The service may only be requested in a confirmed mode.  A reply is
   expected.

4.  The CMOT Architecture

   The CMOT (CMIP Over TCP/IP) architecture is based on the OSI
   management framework [15] and the models, services, and protocols
   developed by ISO for network management.  The CMOT architecture
   demonstrates how the OSI management framework can be applied to a
   TCP/IP environment and used to manage objects in a TCP/IP network.
   The use of ISO protocols for the management of widely deployed TCP/IP
   networks will facilitate the ultimate migration from TCP/IP to ISO
   protocols.  The concept of proxy management is introduced as a useful
   extension to the architecture.  Proxy management provides the ability
   to manage network elements that either are not addressable by means
   of an Internet address or use a network management protocol other
   than CMIP.

   The CMOT architecture specifies all the essential components of a
   network management architecture.  The OSI management framework and
   models are used as the foundation for network management.  A
   protocol-dependent interpretation of the Internet SMI [2] is used for
   defining management information.  The Internet MIB [3] provides an
   initial list of managed objects.  Finally, a means is defined for
   using ISO management services and protocols on top of TCP/IP
   transport protocols.  Management applications themselves are not
   included within the scope of the CMOT architecture.  What is
   currently standardized in this architecture is the minimum required
   for building an interoperable multivendor network management system.
   Applications are explicitly left as a competitive issue for network
   developers and providers.

4.1.  Management Models

   The following sections indicate how the CMOT architecture applies the
   OSI managements models and point out any limitations the CMOT
   architecture has as it is currently defined in this memo.

4.1.1.  The Organizational Model

   It is beyond the scope of this memo to define the relations and
   interactions between different management domains.  The current CMOT
   architecture concerns itself only with the operations and
   characteristics of a single domain of management.  The extension of



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   the mechanisms defined here to include multiple domains is left for
   further study.

4.1.2.  The Functional Model

   The CMOT architecture provides the foundation for carrying out
   management in the five functional areas (fault, configuration,
   performance, accounting, and security), but does not address
   specifically how any of these types of management are accomplished.
   It is anticipated that most functional requirements can be satisfied
   by CMIS.  The greatest impact of the functional requirements in the
   various areas will likely be on the definition of managed objects.

4.1.3.  The Information Model

   There are two different SMI specifications that are important to the
   CMOT architecture. The first is the SMI currently being defined by
   ISO [19].  This SMI is important to the CMOT approach because the ISO
   management protocol CMIP has been designed with the ISO model of
   management information in mind.  The second SMI of importance is the
   that defined by the IETF MIB working group for use in defining the
   Internet MIB [3].  This Internet SMI, which is loosely based on a
   simplified version of the ISO SMI, is important because the managed
   objects defined for TCP/IP networks to be used by CMOT are defined in
   terms of it.  Thus, in order to make the CMOT architecture complete,
   it will be necessary to show how the Internet SMI maps into CMIP in
   such a way as to enable it to convey the management information
   defined in the Internet MIB.  This is done in the section devoted to
   management information (section 5).

4.2.  Protocol Architecture

   The objective of the CMOT protocol architecture is to map the OSI
   management protocol architecture into the TCP/IP environment.  The
   model presented here follows the OSI model at the application layer,
   while using Internet protocols at the transport layer.  The ISO
   application protocols used for network management are ACSE, ROSE, and
   CMIP.  Instead of implementing these protocols on top of the ISO
   presentation, session, and transport layer protocols, the protocol
   data units (PDUs) for ACSE, ROSE, and CMIP are carried using the
   Internet transport protocols UDP [20] and TCP [21].  This is made
   possible by means of the lightweight presentation protocol defined in
   RFC 1085 [13] that maps ROSE and ACSE onto TCP/UDP/IP.  The use of
   Internet transport protocols is transparent to network management
   applications, since they are presented with real ISO services.






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4.2.1.  The Lightweight Presentation Layer

   Given that it is desired to put ISO application protocols on top of
   TCP/IP, how is this best accomplished?  It is necessary somehow to
   fill the "gap" between the ISO protocols (ACSE and ROSE) and the
   Internet protocols (UDP and TCP).  Two basic approaches were
   considered.

   One possible approach [23] is to extend the ISO portion of the
   protocol stack down to the transport layer.  The ISO Transport
   Protocol Class 0 (TP 0) then uses TCP instead of an ISO network
   protocol.  Effectively, this treats TCP as a reliable network
   connection analogous to X.25.  This approach allows us to operate
   "standard" ISO applications over TCP regardless of their service
   requirements, since all ISO services are provided.  In this case,
   network management is just another such application.  The major
   drawback with this approach is that full ISO presentation, session,
   and transport layers are expensive to implement (both in terms of
   processing time and memory).

   Another approach is presented in RFC 1085.  Since the service
   elements required for network management (ACSE, ROSE, CMISE) do not
   require the use of full ISO presentation layer services, it is
   possible to define a "streamlined" presentation layer that provides
   only the services required.  This lightweight presentation protocol
   (LPP) allows the use of ISO presentation services over both TCP and
   UDP.  This approach eliminates the necessity of implementing ISO
   presentation, session, and transport protocols for the sake of doing
   ISO network management in a TCP/IP environment.  This minimal
   approach is justified because this non-ISO presentation protocol used
   is very small and very simple.  Thus, the LPP defined in RFC 1085
   provides a compact and easy to implement solution to the problem.
   The resulting CMOT protocol stack is shown in Figure 1.


















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                   Manager                              Agent
           +-----------------------+           +-----------------------+
           |                       |           |                       |
           | +----+ +----+ +-----+ | <-------> | +----+ +----+ +-----+ |
           | |ACSE| |ROSE| |CMISE| |    CMIP   | |ACSE| |ROSE| |CMISE| |
           | +----+ +----+ +-----+ |           | +----+ +----+ +-----+ |
           |                       |           |                       |
           +-----------------------+           +-----------------------+
           |         LPP           |           |         LPP           |
           +-----------------------+           +-----------------------+
           |   TCP    |    UDP     |           |   TCP    |   UDP      |
           +-----------------------+           +-----------------------+
           |         IP            |           |         IP            |
           +-----------------------+           +-----------------------+
           |         Link          |           |         Link          |
           +-----------------------+           +-----------------------+
                      |                                   |
                      |                                   |
                      |                                   |
           =========================================================
                                  Network
           =========================================================

                     Figure 1.  The CMOT Protocol Architecture


   It is important to note that the presentation services provided by
   the LPP are "real" (but minimal) ISO presentation services [24].
   This provides a clear migration path to "full ISO" in the future.
   Such a migration would be accomplished by substituting ISO protocols
   for the Internet protocols TCP, UDP, and IP [25], and replacing the
   LPP with ISO presentation and session protocols.  No changes will be
   required in the ISO application layer protocols.  For this reason,
   investments in application development will be well preserved.

4.2.2.  The Quality of Transport Service

   The quality of transport service needed for network management
   applications is an issue that has caused much controversy, yet it has
   never been resolved.  There are two basic approaches: datagram-
   oriented and connection-oriented.  There are advantages and
   disadvantages to both of these two approaches. While the datagram-
   oriented approach is simple, requires minimal code space, and can
   operate under conditions where connections may not be possible, the
   connection-oriented approach offers data reliability and provides
   guaranteed and consistent service to the driving application.

   This memo does not take sides on this issue.  Rather it passes such



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   resolution to the network management applications, which are
   ultimately the point where the requirements from the underlying
   service need to be determined.  As such, the CMOT protocol
   architecture provides both services.  The presentation layer service
   allows the application to select either high or low quality service
   for the underlying transport.  Depending on this choice, the LPP will
   use either UDP (low quality) or TCP (high quality) to establish the
   application association and carry the application data.  It is
   important, however, for the application to be aware of the quality of
   service that it is using: low quality means low quality!  The use of
   an unreliable transport like UDP necessarily puts more burden on the
   application.

4.3.  Proxy Management

   Proxy is a term that originated in the legal community to indicate an
   entity empowered to perform actions on behalf of another.  In our
   context, a proxy is a manager empowered to perform actions on behalf
   of another manager.  This may be necessary because the manager cannot
   communicate directly with the managed devices either for security or
   other administrative reasons or because of incompatible communication
   mechanisms or protocols.  In either case, the proxy assumes the agent
   role with respect to the requesting manager and the manager role with
   respect to the managed device.

   Some network elements, such as modems or bridges, may not be able to
   support CMIP and all the associated protocols.  In addition, such
   devices may not have Internet addresses.  Such devices are called
   "limited systems".  It may be possible to manage these devices using
   proprietary mechanisms or other standard protocols (such as the IEEE
   802.1 management protocol for managing bridges).  In cases where it
   is desirable to integrate the management of such devices with the
   overall CMOT management of an internet, it is necessary to use proxy
   management.  Some network elements that are not "limited systems" as
   described above may still benefit from the use of proxy management.
   If the management protocol supported by such a system is proprietary
   or some standard protocol other than CMIP (such as SNMP), then CMOT
   proxy management can be used to integrate the management of such
   systems.

   A proxy operates in the following manner.  When a CMOT manager wants
   to send a request to a managed device that it cannot communicate with
   directly, it routes the request to the proxy.  The proxy maps the
   CMIP request into the information schema understood by the managed
   device and sends the appropriate request to the managed device using
   the native management protocol of the device.  When the proxy
   receives the response from the managed device, it uses CMIP to return
   the information to the manager that made the original request.



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   The use of proxy management can be largely transparent to the
   requesting manager, which appears to be exchanging information
   directly with the selected device.  The only thing that is known to
   the manager is that additional "instance" information is required to
   select a particular device managed by the proxy.  Each proxy may
   support many managed devices, using the "instance" information to
   multiplex CMIP requests and responses among them.  The mapping
   between a specific instance and an actual managed device is a local
   matter.  (The use of the CMIP Object Instance field to select a
   particular system to manage by proxy is explained below in section
   5.3.2.2.)

   A proxy may also serve as an "intermediate manager" in another less
   transparent sense.  The proxy manager may be requested to calculate
   summary statistics on information gathered from many different
   managed systems (e.g., the average number of PDUs transmitted or the
   distribution of PDUs transmitted over time).  The proxy may be
   requested to log events transmitted by the managed systems under its
   control and to send to the requesting manager only those events of
   specific types.  When this use of proxy management is made, the
   conceptual schema for managed objects known to both the requesting
   manager and proxy must include definitions of these aggregate managed
   objects (i.e., objects that do not belong to any one managed system).
   How the aggregate statistics would be calculated and logging
   performed based on information from the different devices managed by
   the proxy would be part of the definition of these aggregate managed
   objects.

4.4.  Directory Service

   RFC 1085 specifies the use of a minimal (or "stub") directory
   service.  It specifies how the service name for an OSI application
   entity is converted into an "application entity title." The
   application entity title is then mapped into a presentation address.
   The form of a service name, an application entity title, and a
   presentation address can be found in RFC 1085.

5.  Management Information

   The description of management information has two aspects.  First, a
   structure of management information (SMI) defines the logical
   structure of management information and how it is identified and
   described.  Second, the management information base (MIB), which is
   specified using the SMI, defines the actual objects to be managed.
   The purpose of this section is to show how CMIP is used in the CMOT
   architecture to convey information defined in the Internet MIB.





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5.1.  The Structure of Management Information

   The SMI supplies the model for understanding management information,
   as well as templates and ASN.1 macros that can be used for defining
   actual management information.  The following sections discuss the
   ISO SMI, the Internet SMI, and a way of interpreting the Internet SMI
   in terms of the ISO SMI so that CMIP can be used to carry management
   information defined in terms of the Internet SMI.

5.1.1.  The ISO SMI

   The ISO SMI [19] is based on the abstraction of a "managed object"
   and the various kinds of relationships objects can be involved in.
   The following discussion does not purport to be a complete and
   accurate description of the latest ISO SMI work.  It is intended to
   be a clear presentation of the basic ISO SMI concepts essential for
   understanding the CMIP-specific interpretation of the Internet SMI
   presented in section 5.3.

5.1.1.1.  Managed Objects and Attributes

   Management Information is modeled using object-oriented techniques.
   All "things" in the network that are to be managed are represented in
   terms of managed objects.  A "managed object" is an abstraction (or
   logical view) for the purposes of network management of a
   "manageable" physical or logical resource of the network.  In this
   context, "manageable" means that a particular resource can be managed
   by using CMIP.  Examples of managed objects are protocol entities,
   modems, and connections.

   Each managed object belongs to a particular object class.  An "object
   class" represents a collection of managed objects with the same, or
   similar, properties.  A particular managed object existing in a
   particular network is defined as an "object instance" of the object
   class to which it belongs.  Thus, an object instance represents an
   actual realization of an object class (i.e., a managed object of a
   particular class bound to specific values).  An example of an object
   class is "transport connection." In an actual network, there are a
   number of managed objects (specific transport connections) that are
   instances of this class.  In summary, a managed object type, which is
   called an "object class," is the collection of all actual and
   potential instances of that type.

   Managed objects are fully defined by specifying the "attributes" or
   properties the object has, the CMIS operations that can be performed
   on the object (e.g., M-SET, M-CREATE) and any constraints on those
   operations, specific actions (e.g., self-test) that can be performed
   on the object, events that the object can generate, and information



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   about various relationships the object may be involved in.  All of
   this information relevant to a managed object is typically provided
   by filling in an object template.

   Managed objects contain properties that are referred to as
   attributes.  Attributes are atomic items of information that can only
   be manipulated as a whole.  An example of an attribute is a counter
   providing a specific piece of information, such as the number of
   packets retransmitted.

   Each object class and attribute is assigned a unique identifier (an
   ASN.1 OBJECT IDENTIFIER) for purposes of naming by a registration
   authority.

5.1.1.2.  Management Information Hierarchies

   Managed objects participate in relationships with each other.  There
   are two relationships that are of particular importance for
   management information: the containment relationship and the
   inheritance relationship.  These relationships can be used to
   construct hierarchies of managed objects.  In addition, there is
   another hierarchy defined by the registration process for registering
   identifiers for object classes and attributes.

5.1.1.2.1.  The Registration Hierarchy

   The registration hierarchy is determined by the ASN.1 registration
   tree [5] for assigning OBJECT IDENTIFIERs.  An OBJECT IDENTIFIER is
   an administratively assigned name composed of a series of integers
   traversing a path from the root of the ASN.1 registration tree to the
   node or leaf to be identified.  For example, the sequence of integers
   { iso(1) standard(0) ips-osi-mips(9596) cmip(2) } (1.0.9596.2) can be
   used to uniquely identify the CMIP standard.  Each node of this tree
   has an associated registration authority that determines how numbers
   in the subtree defined by that node are allocated.  In the context of
   management, these OBJECT IDENTIFIERs are used for identifying object
   classes and attributes.  The registration hierarchy is not based on
   any particular relationship between managed objects or between
   managed objects and their attributes.  It is independent of both the
   inheritance and containment relationships described below.  Its
   purpose is simply to generate universally unique identifiers.

5.1.1.2.2.  The Containment Hierarchy

   The containment hierarchy is constructed by applying the relationship
   "is contained in" to objects and attributes.  Objects of one class
   may contain objects of the same or different class.  Objects may also
   contain attributes.  Attributes cannot contain objects or other



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   attributes.  For example, objects of the class "transport entity" may
   contain objects of the class "transport connection"; an object of the
   class "management domain" may contain objects of the class "node." An
   object class that contains another object class is called the
   "superior" object class; an object class that is contained in another
   object class is called the "subordinate" object class.  The
   containment relationships that an object may participate in are part
   of the definition of the object class to which that managed object
   belongs.  All object classes (except the topmost) must have at least
   one possible superior in the containment tree.  The definition of a
   class may permit it to have more than one such superior.  However,
   individual instances of such a class are nevertheless contained in
   only one instance of a possible containing class.

   The containment hierarchy is important because it can be used for
   identifying instances of a managed object.  For example, assume there
   is an object class "domain" that contains an object class "node" that
   contains an object class "transport entity" that contains an object
   class "transport connection." A particular instance of a transport
   connection can be identified by the concatenation of "instance
   information" for each object class in the containment path: {
   domain="organization," node="herakles," transport entity=tp4,
   transport connection=<TSAP-AddressA, TSAP-AddressB> }.

   What constitutes appropriate "instance information" for each object
   class is part of the definition of that object class and is known as
   the "distinguished attribute(s)." A distinguished attribute is
   composed of an OBJECT IDENTIFIER naming the attribute and the value
   of the attribute.  For each object class, the distinguished
   attributes that differentiate instances of that class are
   collectively called the "relative distinguished name." A sequence of
   relative distinguished names (one for each class in the containment
   path) is the "distinguished name" of a managed object.  The example
   given above represents the distinguished name of a transport
   connection.  The containment hierarchy is sometimes referred to as
   the "naming tree", because it is used to "name" a particular instance
   of a managed object.

   The containment relationship also defines an existence dependency
   among its components; an object or attribute can "exist" only if the
   containing object also "exists." Deletion of an object may result in
   deletion of all objects and attributes contained within it.
   Alternately, depending on the definition of the managed object,
   deletion may be refused until all contained managed objects have been
   deleted.






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5.1.1.2.3.  The Inheritance Hierarchy

   The inheritance hierarchy is constructed by applying the relationship
   "inherits properties of" to object classes.  An object class may
   inherit properties of another object class; refinement is obtained by
   adding additional properties.  In this relationship, the parent class
   is called the "superclass" and the inheriting class the "subclass."
   For example, the class "layer entity" may be a superclass of "network
   entity," which in turn is a superclass of "X.25 network entity."
   Attributes defined for "network entity" (e.g., the number of packets
   sent) are automatically defined for "X.25 network entity" without
   having to explicitly include them in the definition for the class
   "X.25 network entity." Thus, inheritance serves as a shorthand for
   defining object classes using object-oriented methodology.  Each
   class (except the topmost) has at least one superclass, but may have
   zero, one, or many subclasses.  Subclasses may in turn have further
   subclasses, to any degree.  A special object called "top" is the
   ultimate superclass.  It has no properties of its own.

   The inheritance hierarchy has no relevance to the naming of object
   instances.  It is useful only insofar as it leads to a manageable and
   extensible technique for the definition of object classes.

5.1.2.  The Internet SMI

   The Internet SMI [2] is designed to be a protocol-independent SMI
   that can be used with both SNMP and CMIP.  For this reason, it is
   necessary for any management protocol that uses this SMI to show how
   it is to be interpreted in a protocol-specific manner.  This is done
   for CMIP in this memo.

   The Internet SMI indicates both how to identify managed objects and
   how to define them.  The Internet SMI defines a registration subtree
   rooted at { iso(1) org(3) dod(6) internet(1) } for the sake of
   registering OBJECT IDENTIFIERs to be used for uniquely identifying
   managed objects.  The current Internet SMI specifies the format for
   defining objects in terms of an "object type" template and an
   associated OBJECT-TYPE ASN.1 macro.  An object type definition
   contains five fields: a textual name, along with its corresponding
   OBJECT IDENTIFIER; an ASN.1 syntax; a definition of the semantics of
   the object type; an access (read-only, read-write, write-only, or
   not-accessible); and a status (mandatory, optional, or obsolete).
   The current Internet SMI does not provide any mechanism for defining
   actions or events associated with a managed object.

   In describing management information, the current Internet SMI does
   not use the notions of "object class" and "attribute" found in the
   ISO SMI.  Only the concepts of "object type" and "object instance"



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   are used.  The Internet SMI shows how to define object types; it
   leaves the specification of object instances as a protocol-specific
   matter.  The current Internet structure of management information is
   simpler and less rich than the corresponding ISO structure. The ISO
   SMI makes a distinction between simple "attributes," which can be
   viewed as "leaf objects" that are the lowest elements of the
   containment hierarchy, and composite "managed objects" that belong to
   an "object class" and have a structure associated with them (that is,
   can contain attributes).  The Internet SMI does not draw this
   distinction; both simple and composite "objects" are defined as
   "object types." What structure is associated with objects in the
   Internet SMI is defined through the deliberate attempt to structure
   the lower part of the Internet registration tree according to
   containment principles.  (Objects that are considered "attributes" of
   other containing objects are defined directly below them in the
   object registration tree.) This results in a certain lack of
   flexibility, since the registration hierarchy is implicitly used to
   define the containment hierarchy.  This means that the Internet SMI
   does not contain a mechanism for defining containment relationships
   that do not happen to coincide with the registration hierarchy.  In
   interpreting the Internet SMI for use with CMIP, it is necessary to
   overcome this limitation.

5.2.  The Management Information Base

   The Management Information Base (MIB) is a "conceptual repository of
   management information." It is an abstract view of all the objects in
   the network that can be managed.  Note that the MIB is conceptual in
   that it does not carry any implications whatsoever about the physical
   storage (main memory, files, databases, etc.) of management
   information.  The SMI provides the guidelines for defining objects
   contained in the MIB.

   The CMOT approach will use the Internet MIB based on the Internet SMI
   described above.  The first version of the Internet MIB, which is the
   product of the IETF MIB working group, is defined in RFC 1066 [3].
   It contains objects divided into eight groups: system, interfaces,
   address translation, IP, ICMP, TCP, UDP, and EGP.  In addition, the
   Internet SMI provides for future versions of the Internet MIB and a
   means for otherwise extending the MIB through the registration of
   managed objects under "private" and "experimental" branches of the
   object registration tree.  Appendix B provides a protocol-specific
   interpretation of the first version of the TCP/IP MIB defined in [3]
   so that it can be used with CMOT.  This interpretation is based on a
   straightforward mapping of the current Internet SMI to the ISO SMI
   (section 5.3).

   The initial version of the Internet MIB concentrates on defining



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   objects associated with various Internet protocols.  It is expected
   that future versions of the Internet MIB and various extensions will
   provide a much richer set of objects to manage, including management
   information about a variety of network devices and systems.  Thus, an
   expanded MIB will allow wide-ranging and powerful management using
   the CMOT approach.

5.3.  An Interpretation of the Internet SMI

   In order to use CMIP to convey information defined in terms of the
   Internet SMI, it is necessary to show how object instances are
   specified and to provide the necessary structure for differentiating
   object class and attributes.  These objectives are both met by
   separating the containment hierarchy used for naming objects from the
   registration hierarchy and by imposing an "object class" structure on
   the Internet SMI.  Using the technique of imposing an object class
   structure does not replace or redefine the object definitions in the
   Internet MIB; it merely provides a necessary gloss or commentary on a
   MIB defined in terms of the Internet SMI.  For example, Appendix B
   references the "object type" definitions found in [3], but imposes
   additional structure on them.

   This object class definition derives from a simplified version of the
   OBJECT-CLASS macro defined in the ISO SMI [19].  The more complex
   definition is not needed for present purposes.  (The object class
   definition presented here could be extended in the future to show
   what actions and events are associated with a managed object.) The
   object class definition has the following fields:

   OBJECT CLASS:
   ------------
      A textual name, termed the OBJECT CLASS DESCRIPTOR, for the object
      class, along with its corresponding OBJECT IDENTIFIER.

   Definition:
      A textual description of the object class.

   Subclass Of:
      The OBJECT CLASS DESCRIPTOR of the object class that is the
      superclass of this object class. This field is used for indicating
      the inheritance relationship.

   Superiors:
      A list of OBJECT CLASS DESCRIPTORs of the possible superior object
      classes of this object class. This field is used for indicating
      the containment relationship.





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   Names:
      A list of OBJECT DESCRIPTORs identifying the OBJECT TYPES that are
      the distinguished attributes of this object class. (The OBJECT-
      TYPE macro is defined in RFC 1065). Attributes listed here will
      normally be present in the Attribute field of the object class
      definition.  This field is used for indicating what attributes
      must be present in the relative distinguished name that indicates
      an instance of this object class.

   Attributes:
      A list of OBJECT DESCRIPTORs identifying the OBJECT TYPES that are
      attributes of this object class. (The OBJECT-TYPE macro is defined
      in RFC 1065). This field is used for indicating the attributes
      that are contained in this object class.

      This object class definition satisfies our objectives for
      interpreting the Internet SMI for use by CMIP.  The Attributes
      field shows what attributes are contained in this object class;
      this makes the necessary distinction between object classes and
      attributes required by CMIP.  Instead of referencing an
      "attribute" def inition (as is done in the ISO SMI), the
      Attributes field references the "object type" definition found in
      RFC 1065 and used to define the Internet-standard MIB in RFC 1066.
      The name, syntax, and access information required for attributes
      is contained in the "object type" definition.  Two things are
      required for specifying an instance of a managed object: a
      containment relationship determining a sequence of object classes
      and a means for specifying the distinguished attributes for an
      object class.  The Superiors field makes the containment
      relationship explicit; it is no longer merely a function of the
      registration tree.  The Names field makes it possible to indicate
      the distinguished attributes for an object class required for
      giving instance information.  Thus, the object class definition
      makes it possible to specify an object instance using CMIP.

5.3.1.  Object Class and Attributes

   The mapping of management information to the CMIS parameters Managed
   Object Class and Attribute Identifier List now becomes apparent.

5.3.1.1.  Object Class

   The CMIS Managed Object Class parameter is the OBJECT IDENTIFIER
   assigned to the particular object class.  For example, the Managed
   Object Class for the object class "ip" (as defined in Appendix B) is

        { mib 4 } = 1.3.6.1.2.1.4.




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5.3.1.2.  Attribute Identifier

   The CMIS Attribute Identifier List parameter is a list of Attribute
   Identifiers.  An Attribute Identifier can be either global or local.
   If it is global, then it is the OBJECT IDENTIFIER assigned to the
   attribute (i.e., "object type") that is being indicated.  For
   example, the global Attribute Identifier for the attribute
   "ipForwarding" (as defined in [3]) is

        { ip 1 } = 1.3.6.1.2.1.4.1.

   If the Attribute Identifier is local, it is an integer that is the
   last component in the OBJECT IDENTIFIER identifying the object.  For
   ipForwarding, the local Attribute Identifier is 1.  In the case where
   the local identifier is used, the leading components of the OBJECT
   IDENTIFIER for the attribute must be the OBJECT IDENTIFIER of the
   containing object class.  This is true for the interpreted Internet
   MIB defined in Appendix B, but may not be true generally.  The local
   identifier is intended to be interpreted relative to the Managed
   Object Class field of the CMIP PDU.  When a local Attribute
   Identifier is encountered in a CMIP PDU, the global form of the
   identifier is formed by prepending the OBJECT IDENTIFIER in the
   Managed Object Class field to the local identifier.  This is valid
   only when scoping is not used (i.e., scoping is "baseObject").  If
   scoping is used, then the global form of the Attribute Identifier
   must be used instead of the local form.

5.3.2.  Management Information Hierarchies

   The following sections show how the three management information
   hierarchies are to be understood for the interpreted Internet SMI.

5.3.2.1.  The Registration Hierarchy

   The registration hierarchy is the global object registration tree
   described in [2].  It is used merely for assigning identifiers for
   object classes and attributes (i.e., "object types" in RFC 1065).

5.3.2.2.  The Containment Hierarchy

   As described above, the containment hierarchy is used to specify an
   object instance.  The Names field of the object class definition
   contains the distinguished attributes for the object class.  The
   OBJECT IDENTIFIER naming the "attribute" together with its value is
   called an attribute value assertion.  A set of attribute value
   assertions (one for each distinguished attribute) is the relative
   distinguished name associated with that object class.  The sequence
   of relative distinguished names for each of the object classes in the



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   containment hierarchy to which a managed object belongs is the
   distinguished name of the object.  An object instance is fully
   specified by a distinguished name.

   Let us take a concrete example from Appendix B.  How would we
   represent an instance of an entry in the IP routing table?  We begin
   by examining the object class in question (ipRouteEntry) and use the
   Superiors field to find the superior class in the containment
   hierarchy (ipRoutingTable).  This process continues until we
   construct the following containment path of object classes: system,
   ip, ipRoutingTable, ipRouteEntry.  Now for each of these object
   classes, we inspect the Names field to find the distinguished
   attribute for that object class.  If no Names field is present (as is
   the case for "ip" and "ipRoutingTable"), then no instance information
   is required at that level.  Both "system" and "ipRouteEntry" have
   Name fields to show what information is expected at that level.  With
   this information, we can construct the following distinguished name
   specifying an instance of an IP routing table entry:


                  baseManagedObjectInstance {
                     distinguishedName {
                        relativeDistinguishedName {    -- system
                           attributeValueAssertion {
                              attributeType { cmotSystemID }
                              attributeValue "gateway1.acme.com"
                           }
                        },
                        relativeDistinguishedName {    -- ipRouteEntry
                           attributeValueAssertion {
                              attributeType { ipRouteDest }
                              attributeValue 10.0.0.51
                           }
                        }
                     }
                  }


   If the system instance information is not present, then it is assumed
   to be the system with which the management association is established
   (i.e., the system receiving the request).

   Note that the object instance tree can contain components of the
   distinguished name that are outside the managed system (node).  This
   enables referencing of objects across management domains (there could
   be an object class "domain") and across a collection of nodes.  In a
   network where several intermediate managers may be involved in a
   request, each intermediate manager can use the "system" portion of



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   the name to determine where to send a request or result.  This
   technique of naming treats each intermediate managing system as a
   proxy manager.  The proxy manager resolves the address of the next
   node in the chain and may use a different protocol to transfer the
   request or result.  Thus, the "system" instance information can be
   used to name devices being managed by proxy.

5.3.2.3.  The Inheritance Hierarchy

   The Internet SMI does not use the inheritance relationship. The
   "Subclass Of" field is present in the object class definition to show
   how the inheritance relationship would be represented and to allow
   for future extensibility.  It is not used for any of the object
   classes defined in Appendix B.

5.4.  Scoping, Filtering, and Synchronization

   Within some services, CMIS provides additional capabilities that are
   related to the SMI.  These are the scoping, filtering,
   synchronization, and linked-reply facilities.  The presence of these
   facilities are indicated by the Multiple Object Selection Functional
   Unit defined in CMIS [11].

   These facilities provide the manager with the ability to operate on a
   collection of managed objects, rather than a single object.  The
   selection of multiple objects occurs in two phases: scoping and
   filtering.  Scoping is used to identify the managed objects to which
   a filter is to be applied.  Then filtering is used to select a subset
   of managed objects that satisfy certain conditions.  If scoping is
   not used, only the "base" managed object indicated by the CMIS
   Managed Object Class parameter is implied.  An example of the use of
   scoping and filtering for selecting a particular managed object (a
   table entry) is given in one of the sample protocol exchanges found
   in Appendix C.

5.4.1.  Scoping

   Scoping is meant to be understood in terms of the containment
   hierarchy.  A position at a certain level of the containment tree is
   defined by the CMIS Managed Object Class parameter.  The CMIS Scope
   parameter is then interpreted relative to this "base" managed object
   (defined by both object class and object instance).  The Scope
   parameter can be used to select the base object alone, all managed
   objects in the entire subtree (of the containment tree) below the
   base object, or all managed objects in the "n"th level (n = 1, 2,
   3,...) below the base object.





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5.4.2.  Filtering

   Within the objects selected as a result of the scope parameter, it is
   possible to further refine the selection of managed objects through
   the use of filtering.  Filtering provides the ability to select a
   subset of these objects based on conditions applied to attributes
   (e.g., IP routing table entries with the "ipRouteAge > 100") and
   logical operations (and, or, not).

5.4.3.  Synchronization

   When multiple managed objects have been selected using scoping and
   filtering, the question of synchronization across object instances
   (such as multiple IP routing table entries) arises.  The two possible
   choices are "best effort" and "atomic." If "best effort"
   synchronization is selected, the failure to apply an operation (e.g.,
   M-SET) to one instance of an object does not affect the effort to
   apply this operation to other instances of the object.  If "atomic"
   synchronization is selected, then the operation is either performed
   on all object instances selected or none.  The default
   synchronization is best effort.

5.4.4.  Linked Replies

   If the reply to a single request for a set of managed objects results
   in more than one managed object being returned, all of these managed
   objects cannot be returned together in a single CMIP response PDU.
   The reason for this is that the structure of the CMIP response PDU
   only has a single field for containing object instance information.
   Since each managed object has its own instance information, each
   managed object must be returned in a separate CMIP PDU.  In such a
   case, the CMIP Linked Reply PDU is used.  The Linked Reply PDU
   provides a means of associating each of the multiple replies with the
   original request that generated them.  Thus, a single CMIP Get
   Request PDU that uses scoping and filtering would result in zero or
   more CMIP Linked Reply PDUs being returned before a final CMIP Get
   Result PDU.

   A linked reply can also be used to segment a CMIP response pertaining
   to a single managed object.  This would only be necessary if UDP is
   being used as the underlying transport and it is not possible to
   return all the information requested about the managed object in a
   single response PDU subject to the size limitations described in
   section 10.2.

5.5.  Accessing Tables

   This section explains how to use the interpreted Internet SMI and MIB



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   to access tables.

5.5.1.  Accessing Whole Tables

   A whole table is accessed by specifying the object class of the
   table, indicating a scoping level of one, and not providing an
   attribute identifier list. The CMIS standard [11] specifies that if
   the attribute identifier parameter is not present, then all attribute
   identifiers are assumed.  The following CMIS parameters would be used
   to return the entire TCP connection table:

        Object Class: { tcpConnTable }
        Object Instance: "empty" (unless proxy management is used)
        Scope: oneLevel(1)
        Filter: not present
        Attribute Identifier List: not present

   By scoping one level below "tcpConnTable," all managed objects of the
   class "tcpConnEntry" are selected.  (The object class "tcpConnEntry"
   is the only object class one level below the object class
   "tcpConnTable" in the containment hierarchy.) The absence of an
   attribute identifier list signals that all attributes of the managed
   object are to be returned (i.e., all fields of the TCP connection
   table entry).

   In reply to this request, each entry of the table will be returned in
   a separate CMIP PDU (either a Linked Reply PDU or a Get Result PDU).
   Each reply CMIP PDU will specify the Object Class "tcpConnEntry" and
   the appropriate Object Instance information for that entry, as well
   as an Attribute List giving the values of each of the fields of the
   table entry.

5.5.2.  Accessing Table Entries

   An entire table entry is accessed by specifying the object class of
   the table entry, providing a distinguished name specifying the
   instance of the table entry, and not providing an attribute
   identifier list. As seen above, the absence of the attribute
   identifier list parameter indicates that all attributes are assumed.
   The absence of a scope parameter indicates that the base managed
   object class is intended.  The following CMIS parameters would be
   used to return the entire IP routing table entry for which the field
   "ipRouteDest" has the value 10.0.0.51:

        Object Class: { ipRouteEntry }
        Object Instance: { ipRouteDest, 10.0.0.51 }
        Scope: not present
        Filter: not present



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        Attribute Identifier List: not present

   The result is returned in a single CMIP Get Result PDU with an
   attribute list consisting of all of the attributes (i.e., fields) of
   the table entry and their corresponding values.

   If the object class field refers to a table entry and no instance
   information is provided to select a particular entry, then a
   "noSuchObjectInstance" CMIP error should be returned.










































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                       Part II: Protocol Agreements

6.  CMOT Protocol Overview

   This part of the document is a specification of the protocols of the
   CMOT architecture. Contained herein are the agreements required to
   implement interoperable network management systems using these
   protocols.  The protocol suite defined by these implementors'
   agreements will facilitate communication between equipment of
   different vendors, suppliers, and networks.  This will allow the
   emergence of powerful multivendor network management based on ISO
   models and protocols.

   The choice of a set of protocol standards together with further
   agreements needed to implement those standards is commonly referred
   to as a "profile." The selection policy for the CMOT profile is to
   use existing standards from the international standards community
   (ISO and CCITT) and the Internet community.  Existing ISO standards
   and draft standards in the area of OSI network management form the
   basis of this CMOT profile.  Other ISO application layer standards
   (ROSE and ACSE) are used to support the ISO management protocol
   (CMIP).  To ensure interoperability, certain choices and restrictions
   are made here concerning various options and parameters provided by
   these standards.   Internet standards are used to provide the
   underlying network transport.  These agreements provide a precise
   statement of the implementation choices made for implementing ISO
   network management standards in TCP/IP-based internets.

   In addition to the Netman working group, there are at least two other
   bodies actively engaged in defining profiles for interoperable OSI
   network management: the National Institute of Science and Technology
   (NIST) Network Management Special Interest Group (NMSIG) and the OSI
   Network Management Forum.  Both of these groups are similar to the
   Netman working group in that they are each defining profiles for
   using ISO standards for network management.  Both differ in that they
   are specifying the use of underlying ISO protocols, while the Netman
   working group is concerned with using OSI management in TCP/IP
   networks.  In the interest of greater future compatibility, the
   Netman working group has attempted to make the CMOT profile conform
   as closely as possible to the ongoing work of these two bodies.

6.1.  The CMOT Protocol Suite

   The following seven protocols compose the CMOT protocol suite: ISO
   ACSE, ISO DIS ROSE, ISO DIS CMIP, the lightweight presentation
   protocol (LPP), UDP, TCP, and IP.  The relation of these protocols to
   each other is briefly summarized in Figure 2.




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                 +----------------------------------------------+
                 |       Management Application Processes       |
                 +----------------------------------------------+

                             +-------------------+
                             |       CMISE       |
                             | ISO DIS 9595/9596 |
                             +-------------------+

                 +------------------+       +--------------------+
                 |        ACSE      |       |        ROSE        |
                 | ISO IS 8649/8650 |       | ISO DIS 9072-1/2   |
                 +------------------+       +--------------------+

                 +-----------------------------------------------+
                 |     Lightweight Presentation Protocol (LPP)   |
                 |                   RFC 1085                    |
                 +-----------------------------------------------+

                 +------------------+       +--------------------+
                 |       TCP        |       |        UDP         |
                 |     RFC 793      |       |      RFC 768       |
                 +------------------+       +--------------------+

                 +-----------------------------------------------+
                 |                     IP                        |
                 |                   RFC 791                     |
                 +-----------------------------------------------+

                      Figure 2.  The CMOT Protocol Suite

6.2.  Conformance Requirements

   A CMOT-conformant system must implement the following protocols:
   ACSE, ROSE, CMIP, LPP, and IP.  A conformant system must support the
   use of the LPP over either UDP or TCP.  The use of the LPP over both
   UDP and TCP on the same system may be supported.  A conformant system
   need not support all CMIS operations.  A conformant system must,
   however, support at least one of the functional unit groups
   (indicating a set of supported services) defined in section 7.1.3.
   The service and protocol selections are described in greater detail
   in the following sections.

6.3.  Abstract Syntax Notation

   The abstract syntax notation for all of the application service
   elements of the CMOT protocol suite is Abstract Syntax Notation One
   (ASN.1) [5].  The LPP is also defined using ASN.1.  The basic



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   encoding rules used for ASN.1 are specified in [6].  Both definite-
   length and indefinite-length encodings are expressly permitted.

7.  Common Management Information Service Element

   The Common Management Information Service Element (CMISE) is
   specified in two ISO documents.  The service definition for the
   Common Management Information Service (CMIS) is given in ISO DIS
   9595-2 [11].  The protocol specification for the Common Management
   Information Protocol (CMIP) is found in ISO DIS 9596-2 [12].

7.1.  CMIS Services

7.1.1.  CMIS Services Overview

   All of the CMIS services listed in Table 1 are allowed with the CMOT
   approach: M-INITIALISE, M-TERMINATE, M-ABORT, M-EVENT-REPORT, M-GET,
   M-SET, M-ACTION, M-CREATE, and M-DELETE.  The specific services
   supported by a system will be determined by the functional unit group
   or groups to which a system belongs.

7.1.2.  Functional Units

   The CMIS services supported are designated in terms of functional
   units [11].  Each functional unit corresponds to the invoker or
   performer aspect of a particular service.  (The terms "invoker" and
   "performer" are taken from ROSE and refer to the caller of and
   responder to a remote operation, respectively.) The "stand alone"
   functional units associated with each of the management services are
   given in Table 2 as functional units 0-17.  The number following the
   name of each functional unit in the table is defined by CMIP [12] to
   identify that particular functional unit.  The functional units are
   used by the CMISE-service-user at the time of association
   establishment to indicate which services it is willing to support.

















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   +---------------------------------+------------------------+------+
   | Functional Unit                 | Service Primitives     | Mode |
   +---------------------------------+------------------------+------+
   | conf. event report invoker(0)   | M-EVENT-REPORT Req/Conf| C    |
   | conf. event report performer(1) | M-EVENT-REPORT Ind/Rsp | C    |
   | event report invoker(2)         | M-EVENT-REPORT Req     | U    |
   | event report performer(3)       | M-EVENT-REPORT Ind     | U    |
   | confirmed get invoker(4)        | M-GET Req/Conf         | N/A  |
   | confirmed get performer(5)      | M-GET Ind/Rsp          | N/A  |
   | confirmed set invoker(6)        | M-SET Req/Conf         | C    |
   | confirmed set performer(7)      | M-SET Ind/Rsp          | C    |
   | set invoker(8)                  | M-SET Req              | U    |
   | set performer(9)                | M-SET Ind              | U    |
   | confirmed action invoker(10)    | M-ACTION Req/Conf      | C    |
   | confirmed action performer(11)  | M-ACTION Ind/Rsp       | C    |
   | action invoker(12)              | M-ACTION Req           | U    |
   | action performer(13)            | M-ACTION Ind           | U    |
   | confirmed create invoker(14)    | M-CREATE Req/Conf      | N/A  |
   | confirmed create performer(15)  | M-CREATE Ind/Rsp       | N/A  |
   | confirmed delete invoker(16)    | M-DELETE Req/Conf      | N/A  |
   | confirmed delete performer(17)  | M-DELETE Ind/Rsp       | N/A  |
   | multiple reply(18)              | Linked Identification  | N/A  |
   | multiple object selection(19)   | Scope, Filter, Sync.   | N/A  |
   | extended service(20)            | Extended Presentation  | N/A  |
   +---------------------------------+------------------------+------+
    C = confirmed, U = non-confirmed, N/A = not applicable

                          Table 2.  Functional Units

   In addition to the stand alone functional units, there are three
   additional functional units.  If any of these additional functional
   units are selected, then at least one of the stand alone functional
   units must be selected.  The multiple reply functional unit makes
   available the use of the linked identification parameter in the
   selected stand alone functional units.  This makes possible the use
   of linked reply (multiple CMIP PDU responses to a single request).
   The multiple object selection functional unit makes available the use
   of the scope, filter, and synchronization parameters in the selected
   stand alone functional units.  If the multiple object selection
   functional unit is selected, then the multiple reply functional unit
   must also be selected.  The extended services functional unit makes
   available presentation layer services in addition to the P-DATA
   service.  Selecting this functional unit has no effect in the context
   of CMOT, since the lightweight presentation layer provides only
   minimal ISO presentation services.






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7.1.3.  Functional Unit Groups

   In order to assist in the reduction of code size and complexity for
   different types of devices, a number of "functional unit groups" have
   been defined.  Each of these groups indicates a set of services
   defined for either a manager or an agent.  The "negotiation"
   concerning which functional unit groups are supported is done by
   means of the Functional Units parameter of the M-INITIALISE service
   (see section 7.1.4.1).  There are five functional unit groups for
   managers: Event Monitor, Monitoring Manager, Simple Manager,
   Controlling Manager, and Full Manager.  Each functional unit group is
   a superset of the preceding group.  There are five functional unit
   groups for agents: Event Sender, Monitored Agent, Simple Agent,
   Controlled Agent, and Full Agent.  Again, each functional unit group
   is a superset of the preceding group.  The operations supported for
   each functional unit group are summarized in Table 3.


   +--------------------+------+-----+-----+-------+------+-----+------+
   |                    |Event | Get | Set |Create/|Action|Mult.|Mult. |
   |Functional Unit     |Report|     |     |Delete |      |Reply|Object|
   |Groups              |      |     |     |       |      |     |Select|
   +--------------------+------+-----+-----+-------+------+-----+------+
   | 1. Event Monitor   | U    | no  | no  | no    | no   | no  | no   |
   | 2. Event Sender    | U    | no  | no  | no    | no   | no  | no   |
   | 3. Monitoring Mgr. | U    | yes | no  | no    | no   | no  | no   |
   | 4. Monitored Agent | U    | yes | no  | no    | no   | no  | no   |
   | 5. Simple Manager  | U    | yes | C   | no    | no   | yes | no*  |
   | 6. Simple Agent    | U    | yes | C   | no    | no   | yes | no*  |
   | 7. Controlling Mgr.| U    | yes | U/C | yes   | no   | yes | yes  |
   | 8. Controlled Agent| U    | yes | U/C | yes   | no   | yes | yes  |
   | 9. Full Manager    | U/C  | yes | U/C | yes   | U/C  | yes | yes  |
   |10. Full Agent      | U/C  | yes | U/C | yes   | U/C  | yes | yes  |
   +--------------------+------+-----+-----+-------+------+-----+------+
    C = confirmed, U = non-confirmed
    * Simple Managers and Agents must support "oneLevel" scoping for all
      and only those cases where it is required to access a whole table
      and may support synchronization other than "best effort"; no support
      for filtering is required.

                       Table 3.  Functional Unit Groups


   A conformant system must support at least one of these functional
   unit groups.  A system may support both a manager group and an agent
   group.  A system only needs to implement the services and service
   primitives required for the groups that it supports.  In addition, a
   system may support services that are not required by any group that



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   it supports.

7.1.4.  M-INITIALISE Parameters

   The M-INITIALISE service is provided by the ACSE A-ASSOCIATE service.
   The parameters for the M-INITIALISE service are defined in [11] and
   summarized in Table 4.


                 +-------------------+-----------+-----------+
                 | Parameter Name    | Req/Ind   | Rsp/Conf  |
                 +-------------------+-----------+-----------+
                 | Functional Units  | Mandatory | Mandatory |
                 | User Information  | Optional  | Optional  |
                 | Access Control    | Optional  | Optional  |
                 +-------------------+-----------+-----------+

                       Table 4. M-INITIALISE Parameters


   Notice that the further agreement has been made that the Functional
   Units parameter is mandatory at all times.  The M-INITIALISE
   parameters are conveyed as ACSE user information in the ACSE request
   PDU.

7.1.4.1.  Functional Units

   The exchange of functional units between the initiating CMISE-
   service-user and the responding CMISE-service-user is required.  This
   allows the CMIS-service-users to inform each other which functional
   units are supported.  CMIP [12] defines a 21-bit BIT STRING to
   communicate which functional units are supported.  A functional unit
   is supported if the corresponding bit in this bit string is one.  The
   correspondence between functional units and functional unit groups is
   given in Table 5.  The left column gives the functional unit
   corresponding to a particular bit position. The numbers along the top
   of the table indicate the functional unit group (the numbers of the
   functional unit groups are given in Table 3).  The various columns
   indicate the value of each bit for a particular functional unit
   group.











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+------------------------------+---+---+---+---+---+---+---+---+---+---+
|Functional Unit               | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10|
+------------------------------+---+---+---+---+---+---+---+---+---+---+
|conf. event report invoker(0) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
|conf. event report perf.(1)   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
|event report invoker(2)       | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 |
|event report performer(3)     | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 |
|confirmed get invoker(4)      | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 |
|confirmed get performer(5)    | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 |
|confirmed set invoker(6)      | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 |
|confirmed set performer(7)    | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 |
|set invoker(8)                | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 |
|set performer(9)              | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 |
|confirmed action invoker(10)  | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
|confirmed action performer(11)| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
|action invoker(12)            | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
|action performer(13)          | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
|confirmed create invoker(14)  | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 |
|confirmed create performer(15)| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 |
|confirmed delete invoker(16)  | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 |
|confirmed delete performer(17)| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 |
|multiple reply(18)            | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 |
|multiple object selection(19) | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
|extended service(20)          | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
+------------------------------+---+---+---+---+---+---+---+---+---+---+
|                              | M | A | M | A | M | A | M | A | M | A |
+------------------------------+---+---+---+---+---+---+---+---+---+---+
        1 = supported, 0 = not supported, M = manager, A = agent

                     Table 5.  Functional Unit Group Values


   The "negotiation" using functional units proceeds as follows.  The
   initiating CMISE-service-user (manager or agent) sends the functional
   units representing the functional unit group to which it belongs.
   The responding CMISE-service-user sends the functional units
   representing the functional unit group to which it belongs.  (If an
   application process belongs to both a manager and an agent functional
   unit group, then both functional unit groups are indicated using the
   same functional unit bit string.) If the functional unit groups
   supported by the two application entities do not allow meaningful
   communication, then either entity may refuse the association.
   Meaningful communication is defined as the ability of the entity to
   invoke or perform at least one CMIS operation supported by the other
   entity (i.e., some "complementary" set of functional units exists).
   After an association has been established, a system must provide the
   proper response for functional units that it has indicated it can
   support and should gracefully refuse other requests in accordance



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   with the protocol.

7.1.4.2.  User Information

   The User Information parameter is optional.  No entity is required to
   send this parameter, but all entities are expected to tolerate
   receipt of it.

   One possible use of the User Information parameter is to convey
   information describing MIB extensions supported by the manager or
   agent.  This can be viewed as a further way of refining the
   application context.  The mechanism for doing this is not defined at
   this time.

7.1.4.3.  Access Control

   The CMIS M-INITIALISE Access Control parameter is optional.  Access
   control is supported on a per association basis using ACSE.  It is
   recommended (but not required) that the access control parameter be
   used for each A-ASSOCIATE request (via M-INITIALISE).

   Access control is also possible on a per request basis with the CMIS
   Access Control parameter. This parameter might be used to implement
   security similar to the community access rights mechanism provided by
   SNMP [4].  It is expected that the Access Control parameter will be
   used to implement the standard TCP/IP authentication mechanism once
   this has been defined.

7.2.  Supporting Services

   The M-INITIALISE, M-TERMINATE, and M-ABORT services assume the use of
   ACSE.  The following ACSE services are required: A-ASSOCIATE, A-
   RELEASE, A-ABORT, and A-P-ABORT.  The rest of the CMIP protocol uses
   the RO-INVOKE, RO-RESULT, RO-ERROR, and RO-REJECT services of ROSE.

7.3.  CMIP Agreements

   The following sections contain specific CMIP agreements in addition
   to those specified in the CMIP standard [12].

7.3.1.  Invoke Identifier

   It is required that there be a unique invoke identifier (present in
   the ROSE PDU) for successive invocations on the same association.
   The invoke identifier is provided by the invoking CMISE-service-user.
   Invoke identifiers should increase monotonically during the lifetime
   of an association.  Semantically, the invoke identifier is a Counter
   as defined in [2].  Unique identifiers will allow the detection of



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   lost and duplicate requests.

7.3.2.  Object Class

   The object class field of all CMIP PDUs shall be limited to the
   "globalForm" choice:


           ObjectClass ::=
                CHOICE {
                     globalForm    [0] IMPLICIT OBJECT IDENTIFIER
                }


7.3.3.  Object Instance

   The object instance field of all CMIP PDUs is limited to the
   "distinguishedName" choice:


           ObjectInstance ::=
                CHOICE {
                     distinguishedName  [2] IMPLICIT DistinguishedName
                }


   The definition for DistinguishedName is imported from CCITT X.500 and
   ISO DIS 9594-2 [26]:

   DistinguishedName ::= RDNSequence
   RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
   RelativeDistinguishedName ::= SET OF AttributeValueAssertion

   The definition for AttributeValueAssertion is contained in CMIP [12]:

   AttributeValueAssertion ::= SEQUENCE { AttributeId, AttributeValue }
   AttributeId ::=
        CHOICE {
              globalId   [0] IMPLICIT OBJECT IDENTIFIER
              localId    [1] IMPLICIT INTEGER
        }
   AttributeValue ::= ANY DEFINED BY attributeId

   Those attributes to be used as the distinguished attributes of a
   managed object are defined at the time of registration of the object
   class and are identified in the NAMES clause of the OBJECT-CLASS
   macro.




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   When there is no instance information to convey about a managed
   object, then the following "empty" object instance shall be used: The
   "distinguishedName" choice of ObjectInstance shall be an RDNSequence
   consisting of a SEQUENCE of one RelativeDistinguishedName. That
   RelativeDistinguishedName shall be an empty SET of
   AttributeValueAssertions.

7.3.4.  Access Control

   The access control parameter is optional.  The receipt of this
   parameter must be tolerated (i.e., gracefully accepted), but a
   receiving entity is free to ignore this information.  The Access
   Control field is defined in [12] as EXTERNAL.  Until a more
   sophisticated access control mechanism is defined, simple
   authentication can be accomplished by using an unencrypted password
   in the access control field.  The definition of this EXTERNAL is the
   same as that for the ACSE Access Control field (section 8.3.2).

7.3.5.  Synchronization

   Support for "best effort" synchronization is required.  Atomic
   synchronization may also be supported, but is not required.

7.3.6.  Scope

   Scoping is supported if the multiple object selection functional unit
   is selected.  If scoping is supported, all values of the scope field
   shall be supported.

7.3.7.  Filter

   Filtering is supported if the multiple object selection functional
   unit is selected.  If filtering is supported, it is not required that
   all features of filtering be supported.  The following are the
   minimal filtering requirements for any system that supports
   filtering.  In the CMIP field CMISFilter, at least two instances of
   the binary operators ("and," "or") must be supported.  Support for
   additional instances of these operators is not required.  Double
   "not" need not be supported.  In FilterItem, the arithmetic
   operations ("equality", "greaterOrEqual," "lessOrEqual") must be
   supported.  The "present" choice of FilterItem must also be
   supported.  It is not required to support string operations (namely,
   the "substrings" choice of the FilterItem type).  Thus, the minimal
   requirements for filtering yield this restricted definition of
   FilterItem:






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              FilterItem ::=
                   CHOICE {
                        equality       [0] AttributeValueAssertion,
                        greaterOrEqual [2] AttributeValueAssertion,
                        lessOrEqual    [3] AttributeValueAssertion,
                        present        [4] AttributeID
                   }


7.3.8.  Attribute Identifier

   Both choices for the CMIP AttributeId field are allowed:


              AttributeId ::=
                   CHOICE {
                        globalId  [0] IMPLICIT OBJECT IDENTIFIER,
                        localId   [1] IMPLICIT INTEGER
                   }


   The "globalId" form of AttributeId is required if scoping is used
   (i.e., the value of the scope field is other than "baseObject").

7.3.9.  Event Type Identifier

   Both choices for the CMIP EventTypeId field are allowed:


              EventTypeId ::=
                   CHOICE {
                        globalId  [6] IMPLICIT OBJECT IDENTIFIER,
                        localId   [7] IMPLICIT INTEGER
                   }


7.3.10.  Action Type Identifier

   Both choices for the CMIP ActionTypeId field are allowed:


              ActionTypeId ::=
                   CHOICE {
                        globalId  [2] IMPLICIT OBJECT IDENTIFIER,
                        localId   [3] IMPLICIT INTEGER
                   }





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   The "globalId" form of ActionTypeId is required if scoping is used
   (i.e., the value of the scope field is other than "baseObject").

7.3.11.  Time Fields

   The "eventTime" field of the m-EventReport Invoke PDU and the m-
   EventConfirmedReport Invoke PDU must be present.

   The "currentTime" field of the following PDUs must be present: the
   m-EventReport Confirmed Result PDU, the m-Get Result PDU, the m-Set
   Result PDU, the m-Action Confirmed Result PDU, the m-Create Result
   PDU, the m-Delete Result PDU, the GetListError Error PDU, and the
   SetListError Error PDU.

   All CMIP time fields shall use the ASN.1 GeneralizedTime type defined
   in [5] with 1 millisecond granularity.

   If the system generating the PDU does not have the current time, yet
   does have the time since last boot, then GeneralizedTime can be used
   to encode this information.  The time since last boot will be added
   to the base time "0001 Jan 1 00:00:00.00" using the Gregorian
   calendar algorithm.  (In the Gregorian calendar, all years have 365
   days except those divisible by 4 and not by 400, which have 366.) The
   use of the year 1 as the base year will prevent any confusion with
   current time.

   If no meaningful time is available, then the year 0 shall be used in
   GeneralizedTime to indicate this fact.

7.3.12.  Response PDUs

   Both the "managedObjectClass" and "managedObjectInstance" fields must
   be present in the following CMIP response PDUs: the m-EventReport
   Confirmed Result PDU, the m-Get Result PDU, the m-Set Result PDU, the
   m-Action Confirmed Result PDU, the m-Create Result PDU, the m-Delete
   Result PDU, the GetListError Error PDU, and the SetListError Error
   PDU.  The "managedObjectInstance" field must be present in the
   ProcessingFailure Error PDU.  The "managedObjectClass" field must be
   present in the NoSuchArgument Error PDU.

7.3.13.  Error PDUs

   The "globalId" form of AttributeId is required for the
   NoSuchAttributeId Error PDU and the InvalidAttributeValue Error PDU.

8.  Association Control Service Element

   The Association Control Service Element (ACSE), which is necessary



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   for establishing and releasing application associations, is defined
   in [7] and [8].

8.1.  ACSE Services

   The ACSE service description is detailed in ISO 8649 [7].  All of the
   defined ACSE services are mandatory:

       o  A-ASSOCIATE: This confirmed service is used to initiate an
          application association between application entities.

       o  A-RELEASE: This confirmed service is used to release an
          application association between application entities without
          loss of information.

       o  A-ABORT: This unconfirmed service causes the abnormal release
          of an association with a possible loss of information.

       o  A-P-ABORT: This provider-initiated service indicates the
          abnormal release of an application association by the
          underlying presentation service with a possible loss of
          information.

   Mappings of the ACSE services to presentation services and ACSE APDUs
   are shown in Table 6, along with a section reference to ISO 8649 [7].


      +-------------+------------+----------------------+-------------+
      |    ACSE     |  ISO 8649  |        Related       |  Associated |
      |   Service   |  Reference | Presentation Service |    APDUs    |
      +-------------+------------+----------------------+-------------+
      | A-ASSOCIATE |     9.1    |       P-CONNECT      | AARQ, AARE  |
      | A-RELEASE   |     9.2    |       P-RELEASE      | RLRQ, RLRE  |
      | A-ABORT     |     9.3    |       P-U-ABORT      | ABRT        |
      | A-P-ABORT   |     9.4    |       P-P-ABORT      | (none)      |
      +-------------+------------+----------------------+-------------+

                     Table 6.  Mapping of ACSE Services


8.2.  Supporting Services

   ACSE will make use of the following ISO presentation layer services:
   P-CONNECT, P-RELEASE, P-U-ABORT, and P-P-ABORT.  These presentation
   services will be provided by the LPP [13].






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8.3.  ACSE Protocol

   The ACSE protocol specification is found in ISO 8650 [8]. All five
   ACSE APDUs specified in the standard are mandatory.

8.3.1.  Application Context Name

   The Application Context Name takes the form of an OBJECT IDENTIFIER.
   The value of this OBJECT IDENTIFIER includes both the version of CMOT
   being used for this association and the version number of the highest
   version of the Internet-standard MIB supported by the manager or
    agent.  The application context name has the following generic form:


                 { iso(1) org(3) dod(6) internet(1) mgmt(2) mib(n)
                   cmot(9) cmotVersion(1) version-number(v) }

                 where n = highest MIB version supported and
                       v = version of CMOT supported


   For the version of CMOT defined in these agreements, "version-number"
   has the value of one (1). This version of CMOT implies the versions
   of the ISO protocols specified in this memo (see Figure 2).

8.3.2.  User Information

   The following CMIS M-INITIALISE parameters are all mapped onto the
   ACSE User Information parameter: Functional Units, User Information,
   and Access Control.  (See section 7.1.4 for more information on the
   CMIS M-INITIALISE parameters.) ACSE User Information is defined in
   ISO 8650 as follows:

              Association-information ::= SEQUENCE OF EXTERNAL

   The ASN.1 defined type EXTERNAL, which is defined in section 35 of
   ISO 8824 [5], requires both an OBJECT IDENTIFIER for identification
   and an associated ASN.1 encoding.

   The OBJECT IDENTIFIER and syntax associated with the ACSE Functional
   Units EXTERNAL definition are found in [12]. The OBJECT IDENTIFIER is
   defined as { iso(1) standard(0) ips-osi-mips(9596) cmip(2) version(1)
   acse(0) functional-units(0) } and the syntax is a BIT STRING.

   The EXTERNAL definition for User Information is left unspecified at
   this time; it will be defined in a future memo.

   If some form of access control is required, a simple unencrypted



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   password can be used.  The EXTERNAL for this simple access control
   will use the OBJECT IDENTIFIER { cmotAcseAccessControl } (Appendix A)
   and the syntax OCTET STRING. A more sophisticated authentication
   mechanism will be defined with another EXTERNAL definition in a
   future memo.

8.3.3.  Presentation Service Parameters

   The values and defaults of parameters to the ACSE primitives that are
   given to the presentation service are specified in RFC 1085 [13].

   For the Presentation Context Definition List parameter to the P-
   CONNECT service [13, p. 10], the value of the Abstract Syntax Name
   associated with the Presentation Context Identifier of value one (1)
   shall be identical to the OBJECT IDENTIFIER used for the Application
   Context Name (section 8.3.1).

   The Quality of Service parameter shall have the value of either
   "tcp-based" or "udp-based."

9.  Remote Operations Service Element

   The Remote Operations Service Element (ROSE), which provides the
   ability to invoke remote operations, is specified in ISO 9072-1 [9]
   and 9072-2 [10].  ROSE can only be used once an association has been
   established between two application entities.  ROSE is used to
   support CMISE; it is not intended to be used directly by management
   application processes.

9.1.   ROSE Services

   The ROSE service definition is detailed in ISO 9072-1 [9].  All of
   the defined ROSE services are mandatory:

       o  RO-INVOKE: This unconfirmed service is used by an invoking
          ROSE-user to cause the invocation of an operation to be
          performed by an invoked ROSE-user.

       o  RO-RESULT: This unconfirmed service is used by an invoked
          ROSE-user to reply to a previous RO-INVOKE indication in the
          case of a successfully performed operation.

       o  RO-ERROR: This unconfirmed service is used by an invoked
          ROSE-user to reply to a previous RO-INVOKE indication in the
          case of an unsuccessfully performed operation.

       o  RO-REJECT-U: This unconfirmed service is used by a ROSE-user
          to reject a request (RO-INVOKE indication) of the other



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          ROSE-user if it has detected a problem.  It may also be used
          by a ROSE-user to (optionally) reject a reply (RO-RESULT
          indication, RO-ERROR indication) from the other ROSE-user.

       o  RO-REJECT-P: This provider-initiated service is used to advise
          a ROSE-user of a problem detected by the ROSE-provider.

   Mappings of ROSE services to ISO presentation services and ROSE APDUs
   are shown in Table 7, along with a section reference to ISO 9072-1
   [9].


      +-------------+------------+----------------------+-------------+
      |    ROSE     | ISO 9072-1 |        Related       |  Associated |
      |   Service   | Reference  | Presentation Service |    APDUs    |
      +-------------+------------+----------------------+-------------+
      | RO-INVOKE   |    10.1    |        P-DATA        |    ROIV     |
      | RO-RESULT   |    10.2    |        P-DATA        |    RORS     |
      | RO-ERROR    |    10.3    |        P-DATA        |    ROER     |
      | RO-REJECT-U |    10.4    |        P-DATA        |    RORJ     |
      | RO-REJECT-P |    10.5    |        P-DATA        |    RORJ     |
      +-------------+------------+----------------------+-------------+


   Table 7.  Mapping of ROSE Services


9.2.  Supporting Services

   ROSE will only make use of the presentation layer service P-DATA.
   This service is provided by the LPP.  The following restrictions are
   a consequence of the use of the LPP: First, mappings to the Reliable
   Transfer Service Element (RTSE) are not possible, since no RTSE is
   present.  Second, no data token is used with the presentation
   services.

9.3.  ROSE Protocol

   The protocol specification for ROSE shall follow ISO 9072-2 [10].
   All four APDUs specified in the standard are mandatory.  In addition,
   the ability to support the correct origination and reception of the
   linked-id protocol element is required if the multiple reply
   functional unit has been selected (section 7.1.2).

9.3.1.  Operation Class

   Since no turn management is required by ROSE, the Operation Class
   parameter may be ignored.



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9.3.2.  Priority

   ROSE will deliver each APDU in a "first in, first out" manner.  Since
   no turn management is required by ROSE, the Priority parameter may be
   ignored.

10.  Lightweight Presentation

   The specification for the lightweight presentation protocol (LPP) is
   contained in RFC 1085, "ISO Presentation Services on top of TCP/IP-
   based internets" [13].  The services defined in that memo are the
   minimal set of ISO presentation services required to support ACSE and
   ROSE.  The protocol specified to provide these services is a
   replacement for the ISO presentation protocol.

10.1.  Lightweight Presentation Services

   All of the ISO presentation services provided by the LPP are
   mandatory: P-CONNECT, P-RELEASE, P-U-ABORT, P-P-ABORT, and P-DATA.

10.2.  Supporting Services

   Depending on the quality of service indicated in the P-CONNECT
   request, the LPP will use either UDP (low quality) or TCP (high
   quality) as the underlying transport protocol.  UDP provides an
   unreliable datagram service, while TCP provides a reliable
   connection-oriented transport service.

   Practically speaking, there are two ways to discover whether a remote
   system supports the LPP over UDP or TCP.  The first is to use some
   undefined form of directory service. This might be nothing more than
   a local table.  The second way is simply to attempt to establish an
   association with the remote application entity using the desired
   quality of service.  If the transport for that service is unavailable
   on the remote system, then the local presentation-service-provided
   will issue a negative P-CONNECT.CONFIRMATION primitive.  This will be
   interpreted by ACSE as a failure to establish an association with the
   desired quality of service.

   The following well-known UDP and TCP port numbers are defined:

             cmot manager     163/tcp
             cmot manager     163/udp
             cmot agent       164/tcp
             cmot agent       164/udp

   When UDP is used, an implementation need not accept a lightweight
   presentation PDU whose length exceeds 484.  The purpose of this



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   restriction is to ensure that CMIP requests and responses can be
   transmitted in a single unfragmented IP datagram.

10.3.  Lightweight Presentation Protocol

   No further agreements are needed for the lightweight presentation
   protocol defined in RFC 1085.

11.  Acknowledgements

   This RFC is the work of many people.  The following members of the
   IETF Netman working group and other interested individuals made
   important contributions:

             Amatzia Ben-Artzi, 3Com
             Asheem Chandna, AT&T Bell Laboratories
             Ken Chapman, Digital Equipment Corporation
             Anthony Chung, Sytek
             George Cohn, Ungermann-Bass
             Gabriele Cressman, Sun Microsystems
             Pranati Kapadia, Hewlett-Packard
             Lee LaBarre, The MITRE Corporation (chair)
             Dave Mackie, 3Com
             Keith McCloghrie, The Wollongong Group
             Jim Robertson, 3Com
             Milt Roselinsky, CMC
             Marshall Rose, The Wollongong Group
             John Scott, Data General
             Lou Steinberg, IBM

12.  References

     [1]  Cerf, V., "IAB Recommendations for the Development of Internet
          Network Management Standards", RFC 1052, April 1988.

     [2]  Rose, M., and K. McCloghrie, "Structure and Identification of
          Management Information for TCP/IP-based internets", RFC 1065,
          August 1988.

     [3]  McCloghrie, K., and M. Rose, "Management Information Base for
          Network Management of TCP/IP-based internets", RFC 1066,
          August 1988.

     [4]  Case, J., M. Fedor, M. Schoffstall, and J. Davin, "A Simple
          Network Management Protocol (SNMP)", RFC 1098, (Obsoletes
          RFC 1067), April 1989.

     [5]  ISO 8824: "Information processing systems - Open Systems



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          Interconnection, Specification of Abstract Syntax Notation One
          (ASN.1)", Geneva, March 1988.

     [6]  ISO 8825: "Information processing systems - Open Systems
          Interconnection, Specification of Basic Encoding Rules for
          Abstract Notation One (ASN.1)", Geneva, March 1988.

     [7]  ISO 8649: "Information processing systems - Open Systems
          Interconnection, Service Definition for Association Control
          Service Element".

     [8]  ISO 8650: "Information processing systems - Open Systems
          Interconnection, Protocol Specification for Association
          Control Service Element".

     [9]  CCITT Recommendation X.219, Working Document for ISO 9072-1:
          "Information processing systems - Text Communication, Remote
          Operations: Model, Notation and Service Definition",
          Gloucester, November 1987.

     [10]  CCITT Recommendation X.229, Working Document for ISO 9072-2:
           "Information processing systems - Text Communication, Remote
           Operations: Protocol Specification", Gloucester,
           November 1987.

     [11]  ISO DIS 9595-2: "Information processing systems - Open
           Systems Interconnection, Management Information Service
           Definition - Part 2: Common Management Information
           Service", 22 December 1988.

     [12]  ISO DIS 9596-2: "Information Processing Systems - Open
           Systems Interconnection, Management Information Protocol
           Specification - Part 2: Common Management Information
           Protocol", 22 December 1988.

     [13]  Rose, M., "ISO Presentation Services on top of TCP/IP-based
           internets", RFC 1085, December 1988.

     [14]  OSI Network Management Forum, "Forum Interoperable Interface
           Protocols", September 1988.

     [15]  ISO DIS 7498-4: "Information processing systems - Open
           Systems Interconnection, Basic Reference Model - Part 4:
           OSI Management Framework".

     [16]  ISO/IEC JTC1/SC21/WG4 N571: "Information processing systems -
           Open Systems Interconnection, Systems Management: Overview",
           London, July 1988.



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     [17]  Klerer, S. Mark, "The OSI Management Architecture: An
           Overview", IEEE Network Magazine, March 1988.

     [18]  Ben-Artzi, A., "Network Management for TCP/IP Networks: An
           Overview", Internet Engineering Task Force working note,
           April 1988.

     [19]  ISO/IEC JTC1/SC21/WG4 N3324: "Information processing
           systems - Open Systems Interconnection, Management
           Information Services - Structure of Management
           Information - Part I: Management Information Model",
           Sydney, December 1988.

     [20]  Postel, J., "User Datagram Protocol", RFC 768, August 1980.

     [21]  Postel, J., "Transmission Control Protocol", RFC 793,
           September 1981.

     [22]  ISO DP 9534: "Information processing systems - Open Systems
           Interconnection, Application Layer Structure", 10 March 1987.

     [23]  Rose, M., "ISO Transport Services on top of the TCP",
           RFC 1006, May 1987.

     [24]  ISO 8822: "Information processing systems - Open Systems
           Interconnection, Connection Oriented Presentation Service
           Definition", June 1987.

     [25]  Postel, J., "Internet Protocol", RFC 791, September 1981.

     [26]  CCITT Draft Recommendation X.500, ISO DIS 9594/1-8: "The
           Directory", Geneva, March 1988.



















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Appendix A - The CMOT Group

   CMOT DEFINITIONS ::= BEGIN

   IMPORTS OBJECT-TYPE FROM RFC1065-SMI;

   IMPORTS mib FROM RFC1066-MIB;

     cmot  OBJECT IDENTIFIER ::= { mib 9 }

     -- The following assignments are made for the purpose of
     -- identification within CMOT and do not refer to MIB objects.

     cmotVersion              OBJECT IDENTIFIER ::= { cmot 1 }

     cmotAcseInfo             OBJECT IDENTIFIER ::= { cmot 2 }
     cmotAcseAccessControl    OBJECT IDENTIFIER ::= { cmotAcseInfo 1 }

     -- The following definition is made for use in referencing a
     -- managed system (for the purpose of proxy management) in the
     -- CMIP Object Instance field. It does not represent a MIB
     -- object.

     cmotSystemID OBJECT-TYPE
             SYNTAX  CmotSystemID
             ACCESS  not-accessible
             STATUS  optional
             ::= { cmot 3 }

     CmotSystemID ::= CHOICE {
             arbitrary     [0] IMPLICIT OCTET STRING,
             proxyIndex    [1] IMPLICIT INTEGER,
             inetAddr      [2] IMPLICIT IpAddress,
             domainName    [3] IMPLICIT OCTET STRING,
             mac802Addr    [4] IMPLICIT OCTET STRING,
             x121Addr      [5] IMPLICIT OCTET STRING,
             nsap          [6] IMPLICIT OCTET STRING,
             netbiosName   [7] IMPLICIT OCTET STRING,
             snaName       [8] IMPLICIT OCTET STRING,
             adminId       [9] IMPLICIT OBJECT IDENTIFIER
     }

      -- All addresses should be conveyed in network-byte order.

   END






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Appendix B - Management Information Summary

   RFC1066-MIB-INTERPRETATION

          { iso org(3) dod(6) internet(1) mgmt(2) 1 }

              DEFINITIONS ::= BEGIN

              IMPORTS mgmt, OBJECT-TYPE FROM RFC1065-SMI;

                mib        OBJECT IDENTIFIER ::= { mgmt 1 }

                system     OBJECT IDENTIFIER ::= { mib 1 }
                interfaces OBJECT IDENTIFIER ::= { mib 2 }
                at         OBJECT IDENTIFIER ::= { mib 3 }
                ip         OBJECT IDENTIFIER ::= { mib 4 }
                icmp       OBJECT IDENTIFIER ::= { mib 5 }
                tcp        OBJECT IDENTIFIER ::= { mib 6 }
                udp        OBJECT IDENTIFIER ::= { mib 7 }
                egp        OBJECT IDENTIFIER ::= { mib 8 }


         -- definition of object class

         OBJECT-CLASS MACRO  ::=
         BEGIN
           TYPE NOTATION  ::= SubClassOf Superiors Names Attributes
           VALUE NOTATION ::= value(VALUE OBJECT IDENTIFIER)

           SubClassOf     ::= "SUBCLASS OF" value(OBJECT-CLASS)
                                            | empty
           Superiors      ::= "SUPERIORS" "{" SuperiorList "}"
                                            | empty
           Names          ::= "NAMES" "{" AttributeList "}"
                                            | empty
           Attributes     ::= "CONTAINS" "{" AttributeList "}"
                                            | empty

           SuperiorList   ::= Superior | Superior "," SuperiorList
           Superior       ::= value(OBJECT-CLASS)

           AttributeList  ::= Attribute | Attribute "," AttributeList
           Attribute      ::= value(OBJECT-TYPE)

         END

         -- the System group




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         system OBJECT-CLASS
                 NAMES  { cmotSystemID }   -- Appendix A
                 CONTAINS  {
                         sysDescr,
                         sysObjectID,
                         sysUpTime
                 }
                 ::= { mib 1 }

         -- the Interfaces group

         interfaces OBJECT-CLASS
                 SUPERIORS  { system }
                 CONTAINS  { ifNumber }
                 ::= { mib 2 }

         ifTable OBJECT-CLASS
                 SUPERIORS  { interfaces }
                 ::= { interfaces 2 }

         ifEntry OBJECT-CLASS
                 SUPERIORS  { ifTable }
                 NAMES { ifIndex }
                 CONTAINS  {
                         ifIndex,
                         ifDescr,
                         ifType,
                         ifMtu,
                         ifSpeed,
                         ifPhysAddress,
                         ifAdminStatus,
                         ifOperStatus,
                         ifLastChange,
                         ifInOctets,
                         ifInUcastPkts,
                         ifInNUcastPkts,
                         ifInDiscards,
                         ifInErrors,
                         ifInUnknownProtos,
                         ifOutOctets,
                         ifOutUcastPkts,
                         ifOutNUcastPkts,
                         ifOutDiscards,
                         ifOutErrors,
                         ifOutQLen
                 }
                 ::= { ifTable 1 }




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RFC 1095                          CMOT                        April 1989


         -- the Address Translation group

         at OBJECT-CLASS
                 SUPERIORS  { system }
                 ::= { mib 3 }

         atTable OBJECT-CLASS
                 SUPERIORS  { at }
                 ::= { at 1 }

         atEntry OBJECT-CLASS
                 SUPERIORS  { atTable }
                 NAMES  {
                         atIfIndex,
                         atNetAddress
                 }
                 CONTAINS  {
                         atIfIndex,
                         atPhysAddress,
                         atNetAddress
                 }
                 ::= { atTable 1 }

         -- the IP group

         ip OBJECT-CLASS
                 SUPERIORS  { system }
                 CONTAINS  {
                         ipForwarding,
                         ipDefaultTTL,
                         ipInReceives,
                         ipInHdrErrors,
                         ipInAddrErrors,
                         ipForwDatagrams,
                         ipInUnknownProtos,
                         ipInDiscards,
                         ipInDelivers,
                         ipOutRequests,
                         ipOutDiscards,
                         ipOutNoRoutes,
                         ipReasmTimeout,
                         ipReasmReqds,
                         ipReasmOKs,
                         ipReasmFails,
                         ipFragOKs,
                         ipFragFails,
                         ipFragCreates
                 }



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RFC 1095                          CMOT                        April 1989


                 ::= { mib 4 }

         -- the IP Interface table

         ipAddrTable OBJECT-CLASS
                 SUPERIORS  { ip }
                 ::= { ip 20 }

         ipAddrEntry OBJECT-CLASS
                 SUPERIORS  { ipAddrTable }
                 NAMES  { ipAdEntAddr }
                 CONTAINS  {
                         ipAdEntAddr,
                         ipAdEntIfIndex,
                         ipAdEntNetMask,
                         ipAdEntBcastAddr
                 }
                 ::= { ipAddrTable 1 }

         -- the IP Routing table

         ipRoutingTable OBJECT-CLASS
                 SUPERIORS  { ip }
                 ::= { ip 21 }

         ipRouteEntry OBJECT-CLASS
                 SUPERIORS  { ipRoutingTable }
                 NAMES  { ipRouteDest }
                 CONTAINS  {
                         ipRouteDest,
                         ipRouteIfIndex,
                         ipRouteMetric1,
                         ipRouteMetric2,
                         ipRouteMetric3,
                         ipRouteMetric4,
                         ipRouteNextHop,
                         ipRouteType,
                         ipRouteProto,
                         ipRouteAge
                 }
                 ::= { ipRoutingTable 1 }

         -- the ICMP group

         icmp OBJECT-CLASS
                 SUPERIORS  { system }
                 CONTAINS  {
                         icmpInMsgs,



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                         icmpInErrors,
                         icmpInDestUnreachs,
                         icmpInTimeExcds,
                         icmpInParmProbs,
                         icmpInSrcQuenchs,
                         icmpInRedirects,
                         icmpInEchos,
                         icmpInEchoReps,
                         icmpInTimestamps,
                         icmpInTimestampReps,
                         icmpInAddrMasks,
                         icmpInAddrMaskReps,
                         icmpOutMsgs,
                         icmpOutErrors,
                         icmpOutDestUnreachs,
                         icmpOutTimeExcds,
                         icmpOutParmProbs,
                         icmpOutSrcQuenchs,
                         icmpOutRedirects,
                         icmpOutEchos,
                         icmpOutEchoReps,
                         icmpOutTimestamps,
                         icmpOutTimestampReps,
                         icmpOutAddrMasks,
                         icmpOutAddrMaskReps
                 }
                 ::= { mib 5 }

         -- the TCP group

         tcp OBJECT-CLASS
                 SUPERIORS  { system }
                 CONTAINS  {
                         tcpRtoAlgorithm,
                         tcpRtoMin,
                         tcpRtoMax,
                         tcpMaxConn,
                         tcpActiveOpens,
                         tcpPassiveOpens,
                         tcpAttemptFails,
                         tcpEstabResets,
                         tcpCurrEstab,
                         tcpInSegs,
                         tcpOutSegs,
                         tcpRetransSegs
                 }
                 ::= { mib 6 }




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RFC 1095                          CMOT                        April 1989


         -- the TCP connections table

         tcpConnTable OBJECT-CLASS
                 SUPERIORS  { tcp }
                 ::= { tcp 13 }

         tcpConnEntry OBJECT-CLASS
                 SUPERIORS  { tcpConnTable }
                 NAMES  {
                         tcpConnLocalAddress,
                         tcpConnLocalPort,
                         tcpConnRemAddress,
                         tcpConnRemPort
                 }
                 CONTAINS  {
                         tcpConnState,
                         tcpConnLocalAddress,
                         tcpConnLocalPort,
                         tcpConnRemAddress,
                         tcpConnRemPort
                 }
                 ::= { tcpConnTable 1 }

         -- the UDP group

        udp OBJECT-CLASS
                 SUPERIORS  { system }
                 CONTAINS  {
                         udpInDatagrams,
                         udpNoPorts,
                         udpInErrors,
                         udpOutDatagrams
                 }
                 ::= { mib 7 }


         -- the EGP group

          egp OBJECT-CLASS
                 SUPERIORS  { system }
                 CONTAINS  {
                         egpInMsgs,
                         egpInErrors,
                         egpOutMsgs,
                         egpOutErrors
                 }
                 ::= { mib 8 }




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RFC 1095                          CMOT                        April 1989


          -- the EGP Neighbor table

          egpNeighTable OBJECT-CLASS
                 SUPERIORS  { egp }
                 ::= { egp 5 }

         egpNeighEntry OBJECT-CLASS
                 SUPERIORS  { egpNeighTable }
                 NAMES  { egpNeighAddr }
                 CONTAINS  {
                         egpNeighState,
                         egpNeighAddr
                 }
                 ::= { egpNeighTable 1 }


         END


































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RFC 1095                          CMOT                        April 1989


Appendix C - Sample Protocol Exchanges

   The following are sample protocol exchanges between a manager and an
   agent.  The manager establishes an association with the agent,
   requests the number of IP address and header errors, requests the
   type of route corresponding to the destination address 10.0.0.51,
   requests the TCP connection with the well-known port for FTP, and
   then releases the association.  All of these samples show the
   lightweight presentation protocol being used over TCP.

   --
   -- the manager sends an ACSE association request carried in a
   -- presentation connect request PDU
   --

   {
      connectRequest {                             -- LPP
         version version-1,
         reference {
            callingSSUserReference "sri-nic.arpa",
            commonReference "880821222531Z"
         },
         asn 1.3.6.1.2.1.9.1.1,
         user-data {                               -- ACSE
            protocol-version version1,
            application-context-name 1.3.6.1.2.1.9.1.1,
            user-information {
               functionalUnits {
                  direct-reference 1.0.9596.2.1.0.0,
                  encoding {
                     single-ASN1-type '010110101010101010110B'
                                                         -- Full Manager
                  }
               }
            }
         }
      }
   }


   --
   -- the agent sends an ACSE association response carried in a
   -- presentation connect response PDU
   --

   {
      connectResponse {                           -- LPP
         user-data {



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            user-information {                    -- ACSE
               functionalUnits {
                  direct-reference 1.0.9596.2.1.0.0,
                  encoding {
                     single-ASN1-type '101001010101010101110B'
                                                           -- Full Agent
                  }
               }
            }
         }
      }
   }


   --
   -- the manager sends a get request to read the values of
   -- ipInHdrErrors and ipInAddrErrors
   --

   {
      userData {                                   -- LPP
         ro-Invoke {                               -- ROSE
            invokeID 10,
            operation-value m-Get(3),
            argument {                             -- CMIP
               baseManagedObjectClass {
                  globalForm ip { 1.3.6.1.2.1.4 }
               },
               baseManagedObjectInstance {
                  distinguishedName {
                     relativeDistinguishedName {}
                  }
               },
               attributeIdList {
                  attributeId {
                     localID 4                     -- ipInHdrErrors
                  },
                  attributeId {
                     localID 5                     -- ipInAddrErrors
                  }
               }
            }
         }
      }
   }






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   --
   -- the agent replies with a get response indicating that
   -- ipInHdrErrors = 0 and ipInAddrErrors = 2
   --

   {
      userData {                                   -- LPP
         ro-Result {                               -- ROSE
            invokeID 10,
            {
               operation-value m-Get(3),
               argument {                          -- CMIP
                  baseManagedObjectClass {
                     globalForm ip { 1.3.6.1.2.1.4 }
                  },
                  baseManagedObjectInstance {
                     distinguishedName {
                        relativeDistinguishedName {}
                     }
                  },
                  currentTime "19880821222541.300000Z",
                  attributeList {
                     attribute {
                        attributeId {
                           localID 4               -- ipInHdrErrors
                        },
                        attributeValue 0
                     },
                     attribute {
                        attributeId {
                           localID 5               -- ipInAddrErrors
                        },
                        attributeValue 2
                     }
                  }
               }
            }
         }
      }
   }


   --
   -- the manager sends a get request to discover the ipRouteType for
   -- the IP routing entry with ipRouteDest = 10.0.0.51
   --





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RFC 1095                          CMOT                        April 1989


   {
      userData {                                   -- LPP
         ro-Invoke {                               -- ROSE
            invokeID 11,
            operation-value m-Get (3),
            argument {                             -- CMIP
               baseManagedObjectClass {
                  globalForm ipRouteEntry { 1.3.6.1.2.1.4.21.1 }
               },
               baseManagedObjectInstance {
                  distinguishedName {
                     relativeDistinguishedName {
                        attributeValueAssertion {
                           attributeType ipRouteDest
                                        { 1.3.6.1.2.1.4.21.1.1 },
                           attributeValue 10.0.0.51
                        }
                     }
                  }
               },
               attributeIdList {
                  attributeId {
                     localID 8                     -- ipRouteType
                  }
               }
            }
         }
      }
   }


   --
   -- the agent replies with a get response indicating the appropriate
   -- route type
   --

   {
      userData {                                   -- LPP
         ro-Result {                               -- ROSE
            invokeID 11,
            {
               operation-value m-Get(3),
               argument {                          -- CMIP
                  baseManagedObjectClass {
                     globalForm ipRouteEntry { 1.3.6.1.2.1.4.21.1 }
                  },
                  baseManagedObjectInstance {
                     distinguishedName {



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                        relativeDistinguishedName {
                           attributeValueAssertion {
                              attributeType ipRouteDest
                                           { 1.3.6.1.2.1.4.21.1.1 },
                              attributeValue 10.0.0.51
                           }
                        }
                     }
                  },
                  currentTime "19880821222613.780000Z",
                  attributeList {
                     attribute {
                        attributeId {
                           localID 8               -- ipRouteType
                        },
                        attributeValue "direct"
                     }
                  }
               }
            }
         }
      }
   }


   --
   -- the manager sends a get request to read the TCP connection with
   -- the well-known port for FTP.
   --

   {
      userData {                                   -- LPP
         ro-Invoke {                               -- ROSE
            invokeID 12,
            operation-value m-Get(3),
            argument {                             -- CMIP
               baseManagedObjectClass {
                  globalForm tcpConnTable { 1.3.6.1.2.1.6.13 }
               },

               baseManagedObjectInstance {
                  distinguishedName {
                     relativeDistinguishedName { }
                  }
               },
               scope oneLevel(1),
               filter {
                  item {



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RFC 1095                          CMOT                        April 1989


                     equality {
                        attributeType tcpConnLocalPort
                              { 1.3.6.1.2.1.6.13.1.3 }
                        attributeValue 21           -- ftp
                     }
                  }
               }
               attributeIdList { } -- an empty list means all attributes
            }
         }
      }
   }


   --
   -- the agent replies with a get response providing the desired TCP
   -- connection information. If more than one TCP connection had
   -- satisfied the filter condition, a series of one or more linked
   -- reply PDUs would have been returned before the final get response.
   --

   {
      userData {                                   -- LPP
         ro-Result {                               -- ROSE
            invokeID 12,
            {
               operation-value m-Get(3),
               argument {                          -- CMIP
                  baseManagedObjectClass {
                     globalForm tcpConnEntry { 1.3.6.1.2.1.6.13.1 }
                  },
                  baseManagedObjectInstance {
                     distinguishedName {
                        relativeDistinguishedName {
                           attributeValueAssertion {
                              attributeType  { tcpConnLocalAddress },
                              attributeValue 128.10.0.34
                           },
                           attributeValueAssertion {
                              attributeType  { tcpConnLocalPort },
                              attributeValue 21
                           },
                           attributeValueAssertion {
                              attributeType  { tcpConnRemAddress },
                              attributeValue 0.0.0.0
                           },
                           attributeValueAssertion {
                              attributeType  { tcpConnRemPort },



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                              attributeValue 0
                           },
                        }
                     }
                  },
                  currentTime "19880821222541.300000Z",
                  attributeList {
                     attribute {
                        attributeId {
                           localId 1              -- tcpConnState
                        },
                        attributeValue LISTEN
                     },
                     attribute {
                        attributeId {
                           localId 2              -- tcpConnLocalAddress
                        },
                        attributeValue 128.10.0.34
                     },
                     attribute {
                        attributeId {
                           localId 3              -- tcpConnLocalPort
                        },
                        attributeValue 21
                     },
                     attribute {
                        attributeId {
                           localId 4              -- tcpConnRemAddress
                        },
                        attributeValue 0.0.0.0
                     },
                     attribute {
                        attributeId {
                           localId 5              -- tcpConnRemPort
                        },
                        attributeValue 0
                     }
                  }
               }
            }
         }
      }
   }








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RFC 1095                          CMOT                        April 1989


   --
   -- the manager sends a presentation release request
   --

   {
      releaseRequest {                             -- LPP
         user-data {                               -- ACSE
            reason normal
         }
      }
   }


   --
   -- the agent sends a presentation release response
   --

   {
      releaseResponse {                            -- LPP
         user-data {                               -- ACSE
            reason normal
         }
      }
   }


Authors' Addresses

   Unnikrishnan S. Warrier
   Unisys Corporation
   2400 Colorado  MS #42-13
   Santa Monica, CA 90406

   Phone: [phone]

   Email: [e-mail]


   Larry Besaw
   Hewlett-Packard
   3404 East Harmony Road
   Fort Collins, CO 80525

   Phone: [phone]

   Email: [e-mail]





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