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Versions: 00                                                            

Networking Working Group                                Gerhard Bogler
Internet Draft                                              Siemens AG
Expires January 16, 1998

             Internet Technology for Integration of Carrier Network
               Management (TMN) and Enterprise Network Management


Status of this Memo

     This document is an Internet-Draft. Internet-Drafts are
     working documents of the Internet Engineering Task Force
     (IETF), its areas, and its working groups. Note that other
     groups may also distribute working documents as Internet-Drafts.

     Internet-Drafts are draft documents valid for a maximum of
     six months and may be updated, replaced, or obsoleted by other
     documents at any time.  It is inappropriate to use Internet-
     Drafts as reference material or to cite them other than as
     ``work in progress.''

     To learn the current status of any Internet-Draft, please
     check the ``1id-abstracts.txt'' listing contained in the
     Internet-Drafts Shadow Directories on ftp.is.co.za (Africa),
     nic.nordu.net (Europe), munnari.oz.au (Pacific Rim),
     ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast).

     This memo provides information for the Internet community.
     This memo does not specify an Internet standard of any kind.
     Distribution of this memo is unlimited.


The complexity of telecommunication networks, i.e. enterprise and
carrier networks, has grown over the last two decades. Management
of carrier networks and enterprise networks has followed different
paradigms up to now:

- In carrier networks the Telecommunications Management Network (TMN)
  as created by ITU-T in the early 1980s is still being propagated.

- In enterprise networks the SNMP based approach is widely accepted.

The borders between public (carrier) and private (enterprise) networks
are becoming increasingly transparent, a distinction between both types
of networks may soon be irrelevant from a network management point of

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In the light of this development an integrating framework for network
management can be expected to gain rapid importance.

This Internet Draft shows that Internet technology and existing IETF
standards supplemented by a quite limited set of additional specifica-
tions can be used as the basis for a cooperative network management
approach, integrating management of both network management worlds while
leaving their interior essentially untouched.

Table of Contents

1.   Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.   Existing Management Frameworks . . . . . . . . . . . . . . . . . 3
3.   Basic Requirements for a Framework for Integrated
     Network Management . . . . . . . . . . . . . . . . . . . . . . . 6
4.   Framework Architecture . . . . . . . . . . . . . . . . . . . . . 8
5.   Areas for Work in the IETF . . . . . . . . . . . . . . . . . . .13
6.   Security Considerations  . . . . . . . . . . . . . . . . . . . .15
7.   Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . .15
8.   References . . . . . . . . . . . . . . . . . . . . . . . . . . .15
9.   Author's Address . . . . . . . . . . . . . . . . . . . . . . . .16

1. Introduction

1.1  Motivation: the Challenge for Integrated Network Management

Today, enterprise and carrier networks are converging. The discrimina-
tion between enterprise and carrier networks, between IT and telecommuni-
cation is fading. Some consequences for network management are:

- De-regulation in many countries allows organizations to be customers
  (users) of a network as well as providers of a service. Network
  management is shared among many parties: the "classical" network
  operator ('Telco'), the value-adding  service provider, the ISP, the
  enterprise network user operating an own network, brokers/resellers
  of network services etc.

- There is a need to integrate management for different types of nodes
  as the underlying technologies are being more and more integrated.
  Examples include but are not limited to: IP over ATM, MPOA
  (Multiprotocol over ATM, standardized by the ATM-Forum), ATM over

- Some technologies which are commonly used in enterprise and carrier
  networks, e.g. ATM, require integrated management. Note that ATM
  nodes in carrier networks are managed using MIBs according to
  ATM Forum specifications (M4) or ITU-T Recommendations (I.751) while
  ATM nodes in enterprise networks are managed using e.g. the AToM MIB
  of the IETF (RFC 1695).

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- Virtual Private Networks (VPNs) using "public"  network resources
  require cooperation between enterprise and carrier network management.
  VPN owners need to manage their dedicated resources in the carrier

In a nutshell, the challenge that the progressing convergence of
networks presents is to manage several network management worlds
(SNMP, CMIP and existing proprietary solutions) in a consistent way
while preserving the vast investments in existing networks and
network management solutions.

This Internet Draft shows that while much of the needed technology
and the standards are already in place, some additional standardization
efforts will be needed to create a common framework for enterprise and
carrier network management.

1.2  Scope

This Internet-Draft does NOT intend to

- contribute to the discussion about pro's and con's of SNMP and CMIP,
- propose any concept to replace existing SNMP and CMIP based solutions,
- define a new management protocol and a new management scheme.

Instead, this Internet-Draft

- is intended to initiate work on the integration of the traditionally
  separated network management for enterprise networks and carrier
- identifies basic requirements and introduces functional entities
  which enhance the current management architectures,
- proposes areas of work to be tackled by the IETF in order to support
  the requirements.

2  Existing Management Frameworks

Network management for carrier and enterprise networks has been
traditionally separated: TMN framework vs. SNMP/SMI framework.

2.1  The TMN Framework

In the 1980s, the vision was established to monitor and tune all types
of telecommunication network, usually without any manual intervention.
In 1988, the International Telecommunications Union (formerly CCITT)
was the first to define formally the concept of Telecommunications
Management Networks [7].

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The TMN concept relies on 3 pillars:

- its functional architecture (which may be mapped in various ways to
  concrete physical configurations),

- its Logical Layered Architecture (LLA) and

- its standardized interfaces.

2.1.1 The TMN Functional Architecture

TMN according to ITU-T Rec. M.3010 identifies 3 main function blocks:

- Operations Systems Function (OSF) block: The OSF processes management
  information for the purpose of monitoring/coordinating and/or
  controlling telecommunication functions.

- Network Element Function (NEF) block: The NEF is a functional block
  which communicates with the TMN for the purpose of being monitored
  and/or controlled. The NEF is the characterizing part of the Network
  Elements, such as switches.

- Q-Adapter Function (QAF) block: The QAF is used to connect non-TMN
  entities, i.e. entities with non-TMN interfaces. It should be noted
  that from a TMN's point of view SNMP-based Network Elements would have
  to interact with a TMN via a QAF.

The TMN function blocks interact accross TMN reference points.

2.1.2 The TMN Logical Layered Architecture (LLA)

Management functions in the TMN, i.e. the TMN OSFs, have been organized
in 4 layers defining the so called Logical Layered Architecture (LLA)
of the TMN. The layers are:

- Element management layer (EML):
  The EML manages each network element on an individual basis and
  supports an abstraction of the functions provided by the NE layer.

- Network management layer (NML):
  the NML has the responsibility for the management of all the NEs, as
  presented by the EML, both individually and as a set. It is not
  concerned with how a particular element provides services internally.

- Service management layer (SML):
  Service management is concerned with, and responsible for, the
  contractual aspects of services that are being provided to customers
  or are being made available to potential new customers.

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- Business management layer (BML):
  The business management layer has responsibility for the total
  enterprise and is the layer at which agreements between network
  operators are made.

2.1.3 The TMN Interfaces

In order to achieve interoperability between management systems (in TMN
terms Operations Systems = OS) and managed systems, respectively, between
two management systems, TMN defines standardized interfaces (see [9]).
The TMN interfaces are the realization of the TMN reference points.
The most prominent ones are:

- The Q3 interface
  is the interface between management systems and network elements of
  one network operator (corresponding to the q3 reference point in the
  TMN functional architecture shown in Figure 1).
  Q3 has been the main focus of TMN standarization up to now.

- The X interface
  is the interface between management systems of different network
  operators (carrier or enterprise networks).

As basis for the TMN interfaces, the OSI systems management technology
was chosen, a set of standards developed jointly by the International
Standards Organization (ISO) and ITU. According to ITU-T Rec. M.3010,
TMN interfaces consist of a communications protocol stack, defined in
ITU-T Recommendations Q.811 and Q.812 [9] with the CMIP protocol on top
[8] and an information model specified according to ITU-T Recs. X.722
(Guide to the Definition of Managed Objects [10]).

TMN interfaces have been deployed in a number of carrier networks.
In enterprise networks, TMN interfaces have had virtually no influence
up to now.

2.2  The SNMP/SMI Framework

Management of modern enterprise networks is dominantly based on
Internet standards. SNMP version 1 (SNMPv1) is the original
Internet-standard Network Management Framework.

It consists of these three documents:

- RFC 1157 [1] defines the Simple Network Management Protocol (SNMP),
  the protocol used for network access to  managed objects.

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- RFC 1155 [2]  defines the Structure of Management Information (SMI),
  the mechanisms used for describing and naming objects for the purpose
  of management.

- RFC 1212 [3]  defines a more concise description mechanism which is
  wholly consistent with the SMI.

Currently, SNMP is being progressed by the IETF towards SNMP v3.

3. Basic Requirements for a Framework for Integrated Network Management

Two types of basic requirements can be identified: operational
requirements stating the goals, i.e. what shall be achieved by this
management framework, and technology requirements stating which
technology is best suited to achieve these goals.

3.1  Key Operational Requirements

The network management framework shall support

- end-to-end management.
  This requirement addresses the need to cooperate with more than one
  network element to perform complex management tasks at the higher
  management layers, i.e. above element management. An example is the
  creation of an ATM virtual circuit or a SONET path.

- integrated management across multiple network technologies.
  This requirement addresses the need to jointly manage network
  elements of different technologies. An example is coordinated
  management of IP routers and ATM switches.

- cooperation between several (human) operators, management applications
  and managed systems.
  This requirement acknowledges the fact that management in modern
  networks is shared among many parties. Examples include:  management
  of ATM end-to-end accross the boundaries of network operators' domains
  or coordinated provisioning of services involving various departments
  of a service provider's organization (e.g. customer care and switch
  managements, billing department etc.).

- network user access to network management in a 'public' operator's
  domain. This capability is generally known as Customer Network
  Management (CNM).
  This requirement addresses the trend that, in particular,
  operators of enterprise networks require direct control of their
  subscribed services and network resources in a carrier's network.

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  An example is management of a Virtual Private Network (VPN) by a
  corporate user of the carrier network.

- interworking with existing and new SNMP and CMIP based management
  systems. The framework shall allow also for interworking with
  proprietary management systems.
  This requirement addresses the fact that huge investments have been
  made by enterprise and carrier network operators in their infra-
  structures. Any management framework which proposed to replace
  existing solutions, e.g. by introducing a new management protocol
  between management systems and Network Elements is most probably
  bound to fail.

3.2  Technology Requirements

The network management framework shall support

- a WWW-style user interface. Off-the shelf WWW-browsers shall be used
  in the management stations.
  This requirement addresses the fact that the user interfaces provided
  by WWW browsers have received wide acceptance and can be seen as
  state-of-the-art for user interfaces to server-based information

- a common representation of management procedures, operations and
  information elements of different styles and formats.
  This requirement addresses the need to provide the operator with
  one common view of the items he is handling. That means he should be
  able to work at a service (= management task) level view which
  integrates or at least hides details of network resource.
  Another requirement is to integrate management related information
  resources, e.g. operation manuals and training/tutorial information.

- flexible linking of the entities listed above by hyperlinks as used
  in the WWW.
  This requirement is a consequence from the need to support the variety
  of end-to-end operational procedures, network management task steps
  etc. A browser-based user interface is used to present the various
  elements making up integrated network management to the operator.

- customization of this linked HTML structure via the network operators
  management stations and also across a CNM interface.
  This requirement addresses the fact that in practice network
  management is highly network operator specific. Basic management
  operations are combined in very specific ways to fit into the
  respective organization of a network operator. Obviously this is also
  true for enterprise network users. Therefore the requirement for
  customization capabilities holds also for a CNM interface.

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- interfaces to existing management systems (SNMP and CMIP based, and
  This requirement is a consequence from the need to cooperate with
  existing management systems especially at the element management

- the mapping of linked HTML structures to sets/sequences of SNMP/CMIP
  (or proprietary) operations.
  This requirement is a consequence from the fact that from the
  operator's point of view network management tasks, operations and
  information elements are represented by a WWW-like structure while
  interaction with existing management systems has to use existing
  protocols and data structures.

- linking of network originating events (traps in SNMP, event
  notifications in CMIP) to the relevant pages in the SIB.
  This requirement addresses the need for the network operator to get
  knowledge of, and react to, events in the managed network. Examples
  include major outages of network resources, overload of nodes and
  transport systems.

4. Framework Architecture

4.1 Building Blocks

This section proposes three architectural enhancements to the existing
management frameworks which address the requirements in the previous

- the use of WWW technology for representing management tasks
- the introduction of cooperative sessions for network management
- the interworking with SNMP based, CMIP based and proprietary
  management systems.

The principal architectural entities which are introduced are:

- CSC   Cooperative Session Control
- SIB   Server Information Base
- GAP   Gateway Application

Figure 1 gives an overview.  For the sake of simplicity standard
components are not shown such as the WWW-server function and the SNMP
respectively CMIP protocol machines for communication with existing
management systems.

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               --                                      --
              |  |        management stations         |  |
               --        (using WWW browsers)          --
              /  \                                    /  \
              ----         +-----------------+        ----
                |          |                 |          |
                +----------+  Inter/Intranet +----------+
                           |                 |
         --                +---+---------+---+
        |  |                   |         |
         --    SIB       +-----+---------+------+     \
        /  \ customiz.   |  -----       -----   |     |
        ---- interface   | | CSC |-----| SIB |  |     |
          +--------------+  -----       -----   |     |
                         +-+---------+--------+-+      > Management
                           |         |        |       |    Server
                         +-+--+    +-+--+   +-+--+    |
                         |GAP |    |GAP |   |GAP |    |
                         +-+--+    +-+--+   +-+--+    /
                           |         |        |
                +----------+    +----+-----+  +----------+
                |Mgmt.syst.|    |Mgmt.syst.|  |Mgmt.syst.|
                |e.g. SNM  |    |e.g. CM   |  |e.g. propr|
                +----+-----+    +----+-----+  +-----+----+
                     |               |              |
                  +--+-+          +--+-+          +-+--+   Network
                  | NE |          | NE |          | NE |   Elements
                  +----+          +----+          +----+
     e.g. router, bridge    e.g. carrier switch   e.g. transm. equipm.

     Figure 1:  Architectural Entities for WWW-based network management

 The principal functional entities are characterized as follows:

- Cooperative Session Control Function (CSC)

  The CSC controls the multi-party sessions. It handles adding and
  removing of session participants which can be humans (e.g. operator
  staff) and applications (e.g. in existing management systems).
  The CSC uses information represented by so-called cooperation task
  descriptions which are represented by linked HTML pages.

- Server Information Base (SIB)

  The server information base is the repository of entities required for
  WWW-based, cooperative, multi-technology, end-to-end management. It
  contains the following types of entities:

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  - Managed entities representing the resources to be managed;
    this includes also resources in the management server

  - management task descriptions

  - elementary management operations

  - information entities (help texts, multimedia guidance etc.)

  - processing entities, i.e. pieces of code representing management
    logic relating to one or more of the entities above,
    e.g. the mapping of a management task to a set of management
    operations, or the mapping of an elementary operation to an SNMP
    operation etc.

  - event-related entities, i.e. stored event notifications
    (spontaneously emitted in the case of CMIP, retrieved by polling
    in the case of SNMP)

All these entities are represented to the operator by WWW-type pages
connected by hyperlinks.

- Gateway Applications (GAP)

  The management server makes use of Gateway Application (GAP) to
  cooperate with existing (and new) management systems, i.e. for
  sending commands and receiving event information.

  The GAPs include the conversion of management commands and event
  messages to/from WWW representation (HTTP/HTML) and handle access
  authorization to existing management systems.

  GAPs can be used to adapt to management systems based on standard
  MIBs (SNMP or CMIP) or to proprietary management systems. It should
  be noted that this adaptation does not necessarily need to cover the
  complete functionality of the respective element management systems.

4.2  External Interfaces

Internal interfaces, i.e. interfaces within the management server such
as the interface between CSC and SIB (see Fig. 1), are outside the scope
of this Internet Draft.

(1) Interface: Management Station (operator or user domain) -
               Management Server

    This shall be a WWW-type interface (HTTP).

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(2) Interface: Management Server - existing/new element management

    The communication mechanisms for this interface are determined by
    the corresponding management system, i.e. SNMP or CMIP
    (or proprietary).

(3) Interface: SIB Customization

    This shall be a WWW-type interface.
    This interface allows the operator staff to customize the Server
    Information Base. The corresponding MIB (SIB MIB) is described
    using the SNMP framework. This SIB MIB is proposed as a subject for
    further study.

4.3  Principles of the Server Information Base (SIB)

The SIB consists of a linked structure of WWW-type pages.

The operator performs management tasks by surfing this linked WWW
structure. He follows hyperlinks which lead to management task
descriptions and operation forms (corresponding to elementary
management operations) to be filled in.

Concrete management interaction with an existing EM/NM (element
management/network management) system is implicitly invoked by
clicking at the corresponding hyperlink.

Data and operation results received from an element management system
at one step of a management task can be passed to subsequent steps of
the management task by following predefined hyperlinks.

The operator can view alarm messages originating from the network by
selecting corresponding WWW pages. The operator can access multimedia
guidance information ("help", represented as WWW pages) in any phase of
a management task.

Gateway applications are responsible for interworking with the existing
element managers. This includes coordination of these interactions.

An example may illustrate these principles:

  A member of an operator's staff accesses network management
  functionality  by entering the URL designated for end-to-end
  management. This causes a start page to pop up.

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  Let's assume that the staff member intends to create an ATM PVC
  (Permanent Virtual Circuit). By following the appropriate hyperlinks
  he will finally arrive at a task description page titled 'Create an

  At this point the staff member has several options:

  - to enter immediately the requested information for creating the
    ATM PVC, e.g. Quality of Service (QoS) parameters, identification
    of the respective end points in the network elements etc.

  - to ask for further information about the task, i.e. request a
    description of the procedure 'how to create an ATM PVC' or request
    information about syntax and/or semantics of a specific parameter,
    e.g. QoS.

  - to request information about availability, current status etc. of
    the network resources required for that task.

  - to request another human operator or management to join the
    management session; an example may be to query the account status
    of the future owner of the ATM PVC being provisioned.

  The staff member can choose between these options by selecting the
  appropriate hyperlink.

  He is guided through the whole management task step by step, being
  offered only those hyperlinks which are relevant depending on the
  status of the task.

  After providing all the information needed to create the ATM PVC,
  execution of the single elementary operations which make up the
  task is triggered in the respective element management systems.
  These element management systems perform the necessary actions on the
  network elements in their respective domains.

  The responses of the element managers are collected, corresponding
  HTML pages are created and stored in the SIB. A summary response
  page is generated and stored in the SIB.

  Finally the staff member who has initiated the management task is
  informed about completion of this task.

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5. Areas for Work in the IETF

5.1  What is Already in Place, or Currently under Work?

The majority of the needed technology and standards is already in place:

Transport Protocols:

  IETF:       IP, TCP, UDP, HTTP
  ISO/ITU-T:  OSI layers 1-6, layer 7 association control (ACSE)

No additional standardization effort is necessary in this area.

Management Protocols/MIBs:

  IETF:       SNMP, SMI, many equipment specific MIBs
  ISO/ITU-T:  CMIP, GDMO, several application specific MIBs

  SNMP version 3 is currently under work.

No additional standardization efforts in the management protocol area
are proposed in this Internet draft.
MIB efforts are proposed in section 5.2.

User Interfaces:

  IETF:       HTML and add-ons

No additional standardization efforts in the user interface area are
proposed in this Internet draft.

5.2  What Needs Still to Be Done?

In order to fulfill the requirements for integrated network management
some additions to the existing technology/standards are proposed:


  Work is proposed to determine and detail the functional entities and
  their principal interaction needed for cooperative, WWW based network
  management. This framework should also cover security aspects.

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Multi-party Sessions:

  Work is proposed to investigate usability of protocols defined by the
  mmusic-group (Session Initiation Protocol; Session Description
  Protocol) for network management.


  Work is proposed for creating a SIB MIB for managing the Server
  Information Base (SIB). This 'SIB MIB' shall be used by the network
  operator and (parts of it) also by selected users via a CNM interface.

  The SIB MIB shall cover managed objects representing:

  - management tasks

  - elementary management operations (which are mapped by GAPs to SNMP
    or CMIP operations)

  - information entities (e.g. help texts, multimedia guidance
    information etc.)

  - processing entities, i.e. software components performing a specific
    task, such as plausibility checks etc.

  - grouping entities of the SIB to new complex  SIB entities

  - linking entities of the SIB

  - network originating events

  - managed objects representing supporting entities (e.g. event logs)

Mapping (GAPs):

  Work is proposed to investigate the rules for mapping between the
  linked HTML structure of the SIB and the elementary management
  operations determined by the cooperating management systems (SNMP,
  CMIP). An initial proposal addressing this topic was submitted in
  11/96 as an Internet Draft (in the meantime deleted).

What kind of RFCs should be created?

The output of this activity could be structured as follows:

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RFC 'Requirements and Framework':
  requirements and framework architecture of WWW-based integrated
  network management  (scope: roughly characterized by the contents of
  sections 2 and 3 of this Internet draft). This should include also
  security aspects of integrated network management.

RFC 'Mapping':
  mapping management tasks (procedures), management  elementary
  operations, text and multimedia information  to  URLs  (design a
  scheme which allows to represent and address the various entities
  which make up network management using WWW techniques).

  A 'Customizing MIB' for the support of management of the server
  information base. This MIB shall support creating, deleting and
  modifying management tasks and other entities of the SIB.

A further RFC which may be created (depending on the usability of
IP session protocol for cooperative network management):

RFC 'CSC':  This RFC could cover the application and management of a
multi-party session control for network management. This includes a
'session control MIB'.

6. Security Considerations

Security considerations are not discussed in this initial draft.

7. Acknowledgments

The author is indebted for valuable comments from Reinhard Scholl
and Max Sevcik.

8. References

[1]  J. Case, M.Fedor, M. Schoffstall and C. Davin, "The Simple
            Network Management Protocol (SNMP)", RFC 1157, May 1990

[2]  M. Rose, K. McCloghrie,"Structure and Identification of Management
            Information for TCP/IP-based Internets", RFC 1155, May 1990

[3]  M. Rose, K. McCloghrie, "Concise MIB Definitions",
            RFC 1212, March 1991

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[4]  T. Berners-Lee, R. Fielding and H. Frystyck, "Hypertext Transfer
            Protocol, HTTP/1.0", RFC 1945, May 1996,

[5]  T. Berners-Lee, D. Connolly: "Hypertext Markup Language 2.0",
            RFC 1866, November 1995.

[6]  T. Berners-Lee, L. Masinter, M. McCahill, "Uniform Resource
            Locators (URL)", RFC 1738, December 1994.

[7]  ITU-T: Recommendation M.3010 "Principles for a Telecommunications
            Management Network",

[8]  ISO/IEC, ITU-T, Information Technology - OSI, Common Management
            Information Protocol (CMIP) -
            Part 1: Specification ISO/IEC 9596-1, ITU-T
            Recommendation X.711

[9]  ITU-T, Lower Layer Protocol Profiles  for the Q3 Interface,
            Recommendation Q.811
            Higher Layer Protocol Profiles for the Q3 Interface,
            Recommendation Q.812

[10] ISO/IEC, ITU-T, Information Technology - OSI, Guidelines for the
            Definition of Managed Objects, Recommendation X.722

[11] ITU-T, Asynchronous Transfer Mode (ATM) Management of the
            Network Element View, Recommendation I.751

[12] ATM Forum, M4 Interface Requirements and Logical MIB:
            ATM Network Element View, af-nm-0020.000, October 1994
     ATR Forum, CMIP Specification for the M4 Interface,
            af-nm-0027.001, September 1995

[13] M. Ahmed, K. Tesink, IETF, "Definition of Managed Objects for ATM
            Management version 8.0 using SMIv2,  RFC 1695

9. Author's Address

Gerhard Bogler

Siemens AG,
Hofmannstrasse 51,
D-81359 Munich, Germany
tel.: +49-89-722 27685,
fax:  +49-89-722 23528,

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