rfc3198.txt

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Network Working Group                                      A. Westerinen
Request for Comments: 3198                                 J. Schnizlein
Category: Informational                                    Cisco Systems
                                                            J. Strassner
                                                  Intelliden Corporation
                                                            M. Scherling
                                                                   xCert
                                                                B. Quinn
                                                          Celox Networks
                                                               S. Herzog
                                                        PolicyConsulting
                                                                A. Huynh
                                                     Lucent Technologies
                                                              M. Carlson
                                                        Sun Microsystems
                                                                J. Perry
                                                       Network Appliance
                                                           S. Waldbusser
                                                           November 2001


                Terminology for Policy-Based Management

Status of this Memo

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

Copyright Notice

   Copyright (C) The Internet Society (2001).  All Rights Reserved.

Abstract

   This document is a glossary of policy-related terms.  It provides
   abbreviations, explanations, and recommendations for use of these
   terms.  The document takes the approach and format of RFC 2828, which
   defines an Internet Security Glossary. The intent is to improve the
   comprehensibility and consistency of writing that deals with network
   policy, particularly Internet Standards documents (ISDs).










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Table of Contents

   1. Introduction...................................................  2
   2. Explanation of Paragraph Markings..............................  3
   3. Terms..........................................................  3
   4. Intellectual Property.......................................... 16
   5. Acknowledgements............................................... 17
   6. Security Considerations........................................ 17
   7. References..................................................... 17
   8. Authors' Addresses............................................. 19
   9. Full Copyright Statement....................................... 21

1. Introduction

   This document provides abbreviations, definitions, and explanations
   of terms related to network policy.  All definitions are provided in
   Section 3, with the terms listed in alphabetical order.

   The intent is to improve the comprehensibility and consistency of
   Internet Standards documents (ISDs) -- i.e., RFCs, Internet-Drafts,
   and other material produced as part of the Internet Standards Process
   [RFC2026].  Benefits across the ISDs are well-stated in the
   Introduction to RFC 2828 [RFC2828]:

   o  "Clear, Concise, and Easily Understood Documentation" - Requires
      that the set of terms and definitions be consistent, self-
      supporting and uniform across all ISDs.

   o  Technical Excellence - Where all ISDs use terminology accurately,
      precisely, and unambiguously.

   o  Prior Implementation and Testing - Requires that terms are used in
      their plainest form, that private and "made-up" terms are avoided
      in ISDs, and that new definitions are not created that conflict
      with established ones.

   o  "Openness, Fairness, and Timeliness" - Where ISDs avoid terms that
      are proprietary or otherwise favor a particular vendor, or that
      create a bias toward a particular technology or mechanism.

   Common and/or controversial policy terms are defined.  These terms
   are directly related and specific to network policy.

   Wherever possible, this document takes definitions from existing
   ISDs.  It should be noted that:

   o  Expired Internet-Drafts are not referenced, nor are their
      terminology and definitions used in this document.



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   o  Multiple definitions may exist across the ISDs.  Each definition
      is listed, with its source.

2. Explanation of Paragraph Markings

   Section 3 marks terms and definitions as follows:

   o  Capitalization: Only terms that are proper nouns are capitalized.

   o  Paragraph Marking: Definitions and explanations are stated in
      paragraphs that are marked as follows:

      -  "P" identifies basic policy-related terms.

      -  "T" identifies various techniques to create or convey policy-
         related information in a network.  For example, COPS and an
         "Information Model" are two techniques for communicating and
         describing policy-related data.  SNMP and MIBs are another.

      -  "A" identifies specific Work Groups and general "areas of use"
         of policy.  For example, AAA and QoS are two "areas of use"
         where policy concepts are extremely important to their function
         and operation.

3. Terms

   Note:  In providing policy definitions, other "technology specific"
   terms (for example, related to Differentiated Services) may be used
   and referenced.  These non-policy terms will not be defined in this
   document, and the reader is requested to go to the referenced ISD for
   additional detail.

   $ AAA
      See "Authentication, Authorization, Accounting".

   $ abstraction levels
      See "policy abstraction".

   $ action
      See "policy action".

   $ Authentication, Authorization, Accounting (AAA)
      (A) AAA deals with control, authentication, authorization and
          accounting of systems and environments based on policies set
          by the administrators and users of the systems.  The use of
          policy may be implicit - as defined by RADIUS [RFC2138]. In
          RADIUS, a network access server sends dial-user credentials to
          an AAA server, and receives authentication that the user is



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          who he/she claims, along with a set of attribute-value pairs
          authorizing various service features. Policy is implied in
          both the authentication, which can be restricted by time of
          day, number of sessions, calling number, etc., and the
          attribute-values authorized.

   $ CIM
      See "Common Information Model".

   $ Common Information Model (CIM)
      (T) An object-oriented information model published by the DMTF
          (Distributed Management Task Force) [DMTF].  It consists of a
          Specification detailing the abstract modeling constructs and
          principles of the Information Model, and a textual language
          definition to represent the Model.  CIM's schemas are defined
          as a set of files, written in the language of the
          Specification, with graphical renderings using UML [UML].
          Sets of classes and associations represent CIM's Core and
          Common Models, defining an information model for the
          "enterprise" - addressing general concepts (in Core), and
          systems, devices, users, software distribution, the physical
          environment, networks and policy (in the Common Models).  (See
          also "information model".)

   $ Common Open Policy Service (COPS)
      (T) A simple query and response TCP-based protocol that can be
          used to exchange policy information between a Policy Decision
          Point (PDP) and its clients (Policy Enforcement Points, PEPs)
          [RFC2748].  The COPS protocol is used to provide for the
          outsourcing of policy decisions for RSVP [RFC2749]. Another
          usage is for the provisioning of policy [RFC3084]. (See also
          "Policy Decision Point" and "Policy Enforcement Point".)

   $ condition
      See "policy condition".

   $ configuration
      (P) "Configuration" can be defined from two perspectives:
          -  The set of parameters in network elements and other systems
             that determine their function and operation. Some
             parameters are static, such as packet queue assignment and
             can be predefined and downloaded to a network element.
             Others are more dynamic, such as the actions taken by a
             network device upon the occurrence of some event.  The
             distinction between static (predefined) "configuration" and
             the dynamic state of network elements blurs as setting
             parameters becomes more responsive, and signaling controls
             greater degrees of a network device's behavior.



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          -  A static setup of a network element, done before shipment
             to a customer and which cannot be modified by the customer.
          The first is the accepted usage in the Internet community.

   $ COPS
      See "Common Open Policy Service".

   $ data model
      (T) A mapping of the contents of an information model into a form
          that is specific to a particular type of data store or
          repository.  A "data model" is basically the rendering of an
          information model according to a specific set of mechanisms
          for representing, organizing, storing and handling data.  It
          has three parts [DecSupp]:
          -  A collection of data structures such as lists, tables,
             relations, etc.
          -  A collection of operations that can be applied to the
             structures such as retrieval, update, summation, etc.
          -  A collection of integrity rules that define the legal
             states (set of values) or changes of state (operations on
             values).
          (See also "information model".)

   $ DEN
      See "Directory Enabled Networks".

   $ Differentiated Services (DS)
      (T) The IP header field, called the DS-field.  In IPv4, it defines
          the layout of the ToS (Type of Service) octet; in IPv6, it is
          the Traffic Class octet [RFC2474].
      (A) "Differentiated Services" is also an "area of use" for QoS
          policies.  It requires policy to define the correspondence
          between codepoints in the packet's DS-field and individual
          per-hop behaviors (to achieve a specified per-domain
          behavior).  In addition, policy can be used to specify the
          routing of packets based on various classification criteria.
          (See also "Quality of Service" and "filter".)

   $ diffserv
      See "Differentiated Services".

   $ Directory Enabled Networks (DEN)
      (T) A data model that is the LDAP mapping of CIM (the Common
          Information Model).  Its goals are to enable the deployment
          and use of policy by starting with common service and user
          concepts (defined in the information model), specifying their





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          mapping/storage in an LDAP-based repository, and using these
          concepts in vendor/device-independent policy rules [DMTF].
          (See also "Common Information Model" and "data model".)

   $ domain
      (P) A collection of elements and services, administered in a
          coordinated fashion.  (See also "policy domain".)

   $ DS