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Interface to Network Security Functions (I2NSF) Terminology

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This is an older version of an Internet-Draft whose latest revision state is "Expired".
Authors Susan Hares , John Strassner , Diego Lopez , Liang Xia
Last updated 2016-05-17 (Latest revision 2016-05-02)
Replaces draft-hares-i2nsf-terminology
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I2NSF                                                           S. Hares
Internet-Draft                                              J. Strassner
Intended status: Informational                                    Huawei
Expires: October 29, 2016                                       D. Lopez
                                                          Telefonica I+D
                                                                  L. Xia
                                                          April 29, 2016

      Interface to Network Security Functions (I2NSF) Terminology


   This document defines a set of terms that are used for the Interface
   to Network Security Functions (I2NSF) effort.

Status of this Memo 

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on October 29, 2016.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     5.1.  Informative References  . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   This document defines the terminology for the Interface to Network
   Security Functions(I2NSF) effort.  This section provides some
   background on I2NSF; a detailed problem statement can be found in
   [I-D.ietf-i2nsf-problem-and-use-cases]. Motivation and comparison to
   previous work can be found in [I-D.ietf-i2nsf-gap-analysis].

   Enterprises are now considering using network security functions
   (NSFs) hosted by service providers due to the growing challenges and
   complexity in maintaining an up to date secure infrastructure that
   complies with regulatory requirements, while controlling costs.  The
   hosted security service is especially attractive to small and medium
   size enterprises who suffer from a lack of security experts to
   continuously monitor, acquire new skills and propose immediate
   mitigations to ever increasing sets of security attacks.  Small and
   medium-sized businesses (SMBs) are increasingly adopting cloud-based
   security services to replace on-premises security tools, while larger
   enterprises are deploying a mix of traditional (hosted) and cloud-
   based security services.

   To meet the demand, more and more service providers are providing
   hosted security solutions to deliver cost-effective managed security
   services to enterprise customers.  The hosted security services are
   primarily targeted at enterprises, but could also be provided to any
   kind of mass-market customers as well.  NSFs are provided and
   consumed in increasingly diverse environments.  Users of NSFs may
   consume network security services hosted by one or more providers,
   which may be their own enterprise, service providers, or a
   combination of both.

   It is out of scope in this document to define an exhaustive list of
   terms that are used in the security field; the reader is referred to
   other applicable documents, such as [RFC4949].

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2.  Terminology

   AAA:  Authentication, Authorization, and Accounting.  See individual

   Abstraction:  The definition of the salient characteristics and
      behavior of an object that distinguish it from all other types of
      objects.  It manages complexity by exposing common properties
      between objects and processes while hiding detail that is not

   Access Control:  Protection of system resources against unauthorized
      access; a process by which use of system resources is regulated
      according to a security policy, and is permitted by only
      authorized entities (users, programs, processes, or other systems)
      according to that policy [RFC4949].

   Accounting:  The act of collecting information on resource usage for
      the purpose of trend analysis, auditing, billing, or cost
      allocation ([RFC2975] [RFC3539]

   ACL (Acess Control List):  This is a mechanism that implements
      access control for a system resource by enumerating the system
      entities that are permitted to access the resource and stating,
      either implicitly or explicitly, the access modes granted to each
      entity [RFC4949]. A YANG description is defined in

   Action:  Defines what is to be done when a set of conditions are
      met (See I2NSF Action).  (from

   Authentication:  The act of verifying a claimed identity, in the
      form of a pre-existing label from a mutually known name space, as
      the originator of a message (message authentication) or as the
      end-point of a channel (entity authentication) [RFC3539].

   Authorization:  The act of determining if a particular right, such
      as access to some resource, can be granted to the presenter of a
      particular credential [RFC3539].

   B2B:   Business-to-Business.

   Bespoke:  Something made to fit a particular person, customer, or

   Bespoke security management:  Security management systems that are
      make to fit a particular customer.

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   Boolean Clause:  A logical statement that evaluates to either TRUE
      or FALSE.  Also called Boolean Expression.

   Capability:  Defines a set of features that are available from a
      managed entity (see also I2NSF Capability).

   Capability Layer:  Defines an abstraction layer that exposes a set
      of capabilities of the I2NSF system.

   Condition:  A set of attributes, features, and/or values that are to
      be compared with a set of known attributes, features, and/or
      values in order to make a decision.  A Condition, when used in the
      context of a Policy Rule, is used to determine whether or not the
      set of Actions in that Policy Rule can be executed or not.
      Examples of an I2NSF Condition include matching attributes of a
      packet or flow, and comparing the internal state of a NSF to a
      desired state.  [I-D.strassner-supa-generic-policy-info-model]

   Constraint:  A constraint is a limitation or restriction.
      Constraints may be associated with any type of object (e.g.,
      events, conditions, and actions in Policy Rules).

   Constraint Programming:  A type of programming that uses constraints
      to define relations between variables in order to find a
      feasible (and not necessarily optimal) solution.

   Context:  The Context of an Entity is a collection of measured and/
      or inferred knowledge that describe the state and the environment
      in which an Entity exists or has existed.  (from

   Controller:  TBD [Editorial: The definition is lacking content
      ("used interchangeably with Service Provider Security Controller
      or management system throughout this document") and overloaded -
      the two terms should be split into two separate definitions in

   Customer:  A business role of an entity that is involved in the
      definition and/or consumption of services, and the possible
      negotiation of a contract to use services from a Provider.

   DC:  Data Center

   Data Model:  A representation of concepts of interest to an
      environment in a form that is dependent on data repository, data
      definition language, query language, implementation language, and
      protocol (typically one or more of these )

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   Event:  An important occurrence in time of a change in the system
      being managed, and/or in the environment of the system being
      managed.  Examples of an I2NSF Event include time and user actions
      (e.g. logon, logoff, and actions that violate an ACL).  An Event,
      when used in the context of a Policy Rule, is used to determine
      whether the condition clause of an imperative Policy Rule can be
      evaluated or not [I-D.strassner-supa-generic-policy-info-model].

   ECA:  Event - Condition - Action policy (a type of Policy Rule).

   Firewall (FW):  A function that restricts data communication traffic
      to and from one of the connected networks (the one said to be
      'inside' the firewall), and thus protects that network's system
      resources against threats from the other network (the one that
      is said to be 'outside' the firewall) [RFC4949].

   Flow-based NSF:  A NSF that inspects network flows according to a
      set of policies intended for enforcing security properties.  Flow-
      based security also means that packets are inspected in the order
      they are received, and without modification to the packet due to
      the inspection process.

   I2NSF Action:  An I2NSF Action is a special type of Action that is
      used to control and monitor aspects of flow-based Network Security
      Functions.  Examples of I2NSF Actions include providing intrusion
      detection and/or protection, web and flow filtering, and deep
      packet inspection for packets and flows.  An I2NSF Action, when
      used in the context of a I2NSF Policy Rule, may be executed when
      both the event and the condition clauses of its owning I2NSF
      Policy Rule evaluate to true.  The execution of this action may be
      influenced by applicable metadata

   I2NSF Agent:  A software component in a device that implements an
      NSF.  It receives provisioning information and requests for
      operational data (e.g., monitoring data) from an I2NSF client.  It
      is also responsible for enforcing the policies that it receives
      from an I2NSF client.

   I2NSF Capability:  A set of features that are available from an NSF

   I2NSF client:  A software component that uses the I2NSF framework
      to read, write, and/or change provisioning and operational aspects
      of the NSFs that it attaches to.

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   I2NSF Management System:  I2NSF clients operate within a network
      management system, which serves as a collection and distribution
      point for I2NSF security provisioning and filters data.

   I2NSF Policy:  A set of rules that are used to manage and control
      the changing or maintaining of the state of an NSF instance.

   I2NSF Policy Rule:  A policy rule that is adapted for I2NSF usage.
      The I2NSF Policy Rule is assumed to be in ECA form (i.e., an
      imperative structure).  Other types of programming paradigms
      (e.g., declarative and functional) are currently out of scope.
      An example of an I2NSF Policy Rule is, in pseudo-code:

         IF <event-clause> is TRUE

            IF <condition-clause> is TRUE

               THEN execute <action-clause>



      In the above example, the Event, Condition, and Action portions of
      a Policy Rule are all **Boolean Clauses**.

   I2NSF Registry:  A registry that contains I2NSF capability
      information, which can be controlled by the I2NSF Management

   IDS:  Intrusion Detection System (see below).

   IPS:  Intrusion Protection System (see below).

   Information Model:  A representation of concepts of interest to an
      environment in a form that is independent of data repository,
      data definition language, query language, implementation language,
      and protocol [I-D.strassner-supa-generic-policy-info-model].

   Interface:  A set of operations one object knows it can invoke on,
      and expose to, another object.  It is a subset of all operations
      that a given object implements.  The same object may have multiple
      types of interfaces to serve different purposes.  An example of
      multiple interfaces can be seen by considering the interfaces
      include a firewall uses; these include:

      *  multiple interfaces for data packets to traverse through,
      *  an interface for a controller to impose policy,or retrieve the
         results of execution of a policy rule.

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   Intrusion Detection System (IDS):  A system that detects network
      intrusions via a variety of filters, monitors, and/or probes.  An
      IDS may be stateful or stateless.

   Intrusion Protection System (IPS):  A system that protects against
      network intrusions.  An IPS may be stateful or stateless.

   Metadata:  Data that provides information about other data.
      Examples include IETF network management protocols (e.g.  NETCONF,
      RESTCONF, IPFix) or IETF routing interfaces (I2RS).  The I2NSF
      security interface may utilize Metadata to describe and/or
      prescribe characteristics and behavior of the YANG data models.

    Middlebox:  Any intermediary device performing functions other
      than the normal, standard functions of an IP router on the
      datagram path between a source host and destination host

   Network Security Function (NSF):  Software that provides a set of
      security-related services.  Examples include detecting unwanted
      activity and blocking or mitigating the effect of such unwanted
      activity in order to fulfil service requirements.  The NSF can
      also help in supporting communication stream integrity and

   OCL (Object Constraint Language):  A constraint programming language
      that is used to specify constraints (e.g., in UML) (from

   Policy Rule:  A set of rules that are used to manage and control
      the changing or maintaining of the state of one or more managed
      objects.  Often this is shorterned to Rule or Policy (see I2NSF
      policy rule) [I-D.strassner-supa-generic-policy-info-model].

   Profile:  A structured representation of information that
      characterizes the capabilities of an object, typically in a
      specific context.  This may be used to simplify how this object
      interacts with other objects in its environment.  [Editors note:
      John Strassner suggests this is a simplified definition from a
      variety of sources (UAProf and CC/PP).  It does not mention the
      concept of preference, therefore John wonders if we need a
      different definition here.]

   Registry:  is a logically centralized location containing data of a
      particular type; it may optionally contain metadata,
      relationships, and other aspects of the registered data in order
      to use those data effectively.  An I2NSF registry is used to
      contain capability information that can be controlled by the

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   Registration Interface:  An interface dedicated to requesting,
      receiving, editing, and deleting information in a Registry.

   Service Layer:  Software that enables clients to manage security
      policies for their specific flows.  This is also called the
      Client-Facing Interface.

   Service Provider Security Controller:  TBD (Editorial: Place holder
      for a split between controller and security controller

   Tenant:  A group of users that share common access privileges to
      the same software.  An I2NSF tenant may be physical or virtual,
      and may run on a variety of systems or servers.

   Vendor Facing Interface:  This enables vendors to register their
      NSFs, along with the capabilities of their NSFs, with a logically
      centralized authority.

   Virtual NSF:  An NSF that is deployed as a distributed virtual

   Virtual Network Function (VNF):  A virtualized network component,
      such as a router, switch, security box, or AAA Servier.

    VNFM (VNF Manager):  Manager of virtual network functions that
      creates, deletes, manages, and moves VNFs.

   VNFPool:  A collection of interchangeable VNFs (i.e., each VNF has
      the same set of capabilities).

   Virtualization:  Virtualization is a type of software that creates
      a non-physical version of an object.  Examples include virtualized
      operating systems, storagte devices, and networking elements.
      [Editor's notes: Questions from John: Do we want or need to
      differentiate between different tyeps of virtualization?  For
      example: full vs. partial vs.  para-virtualization (all types of
      "hardware virtualization")?  Do we need to introduce OS
      virtualization?  What about application virtualization?]

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3.  IANA Considerations

   No IANA considerations exist for this document.

4.  Security Considerations

   This is a terminology document with no security considerations.

5.  References

5.1.  Informative References

              Hares, S., Moskowitz, R., and D. Zhang, "Analysis of
              Existing work for I2NSF", draft-ietf-i2nsf-gap-analysis-01
              (work in progress), April 2016.

              Hares, S., Dunbar, L., Lopez, D., Zarny, M., and C.
              Jacquenet, "I2NSF Problem Statement and Use cases", draft-
              ietf-i2nsf-problem-and-use-cases-00 (work in progress),
              February 2016.

              Bogdanovic, D., Koushik, K., Huang, L., and Blair, D.,
              "Network Access Control List (ACL) YANG Data Model",
              draft-ietf-netmod-acl-model-07 (work in progress),
              March 2016.

              Baker, F. and P. Hoffman, "On Firewalls in Internet
              Security", draft-ietf-opsawg-firewalls-01 (work in
              progress), October 2012.

              Strassner, J., Halpern, J., and J. Coleman, "Generic
              Policy Information Model for Simplified Use of Policy
              Abstractions (SUPA)", draft-strassner-supa-generic-policy-
              info-model-05 (work in progress), April 2016.

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   [RFC2975]  Aboba, B., Arkko, J., and D. Harrington, "Introduction to
              Accounting Management", RFC 2975, DOI 10.17487/RFC2975,
              October 2000, <>.

   [RFC3234]  Carpenter, B. and S. Brim, "Middleboxes: Taxonomy and
              Issues", RFC 3234, DOI 10.17487/RFC3234, February 2002,

   [RFC3539]  Aboba, B. and J. Wood, "Authentication, Authorization and
              Accounting (AAA) Transport Profile", RFC 3539,
              DOI 10.17487/RFC3539, June 2003,

   [RFC4949]  Shirey, R., "Internet Security Glossary, Version 2",
              FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,

Authors' Addresses

   Susan Hares
   7453 Hickory Hill
   Saline, MI  48176

   Phone: +1-734-604-0332

   John Strassner
   Santa Clara, CA


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   Diego R. Lopez
   Telefonica I+D
   Don Ramon de la Cruz, 82
   Madrid  28006


   Liang Xia (Frank)
   101 Software Avenue, Yuhuatai District
   Nanjing , Jiangsu   210012


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