I2NSF Working Group                                        S. Hares, Ed.
Internet-Draft                                                    Huawei
Intended status: Standards Track                           J. Jeong, Ed.
Expires: 17 May 2022                                              J. Kim
                                                 Sungkyunkwan University
                                                            R. Moskowitz
                                                          HTT Consulting
                                                                  Q. Lin
                                                                  Huawei
                                                        13 November 2021


                    I2NSF Capability YANG Data Model
               draft-ietf-i2nsf-capability-data-model-21

Abstract

   This document defines an information model and the corresponding YANG
   data model for the capabilities of various Network Security Functions
   (NSFs) in the Interface to Network Security Functions (I2NSF)
   framework to centrally manage the capabilities of the various NSFs.

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
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on 17 May 2022.

Copyright Notice

   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights



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   and restrictions with respect to this document.  Code Components
   extracted from this document must include Simplified BSD License text
   as described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Information Model of I2NSF NSF Capability . . . . . . . . . .   4
     3.1.  Design Principles and ECA Policy Model  . . . . . . . . .   5
     3.2.  Conflict, Resolution Strategy and Default Action  . . . .   8
   4.  Overview of YANG Data Model . . . . . . . . . . . . . . . . .  10
   5.  YANG Tree Diagram . . . . . . . . . . . . . . . . . . . . . .  12
     5.1.  Network Security Function (NSF) Capabilities  . . . . . .  12
   6.  YANG Data Model of I2NSF NSF Capability . . . . . . . . . . .  15
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  49
   8.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .  49
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  50
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  51
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  51
     10.2.  Informative References . . . . . . . . . . . . . . . . .  56
   Appendix A.  Configuration Examples . . . . . . . . . . . . . . .  57
     A.1.  Example 1: Registration for the Capabilities of a General
           Firewall  . . . . . . . . . . . . . . . . . . . . . . . .  57
     A.2.  Example 2: Registration for the Capabilities of a
           Time-based Firewall . . . . . . . . . . . . . . . . . . .  59
     A.3.  Example 3: Registration for the Capabilities of a Web
           Filter  . . . . . . . . . . . . . . . . . . . . . . . . .  61
     A.4.  Example 4: Registration for the Capabilities of a VoIP/
           VoLTE Filter  . . . . . . . . . . . . . . . . . . . . . .  62
     A.5.  Example 5: Registration for the Capabilities of a HTTP and
           HTTPS Flood Mitigator . . . . . . . . . . . . . . . . . .  63
   Appendix B.  Acknowledgments  . . . . . . . . . . . . . . . . . .  64
   Appendix C.  Contributors . . . . . . . . . . . . . . . . . . . .  65
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  66















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1.  Introduction

   As the industry becomes more sophisticated and network devices (e.g.,
   Internet-of-Things (IoT) devices, autonomous vehicles, and
   smartphones using Voice over IP (VoIP) and Voice over LTE (VoLTE))
   require advanced security protection in various scenarios, security
   service providers have a lot of problems described in [RFC8192] to
   provide such network devices with efficient and reliable security
   services in network infrastructure.  To resolve these problems, this
   document specifies the information and data models of the
   capabilities of Network Security Functions (NSFs) in a framework of
   the Interface to Network Security Functions (I2NSF) [RFC8329].

   NSFs produced by multiple security vendors provide various security
   capabilities to customers.  Multiple NSFs can be combined together to
   provide security services over the given network traffic, regardless
   of whether the NSFs are implemented as physical or virtual functions.
   Security Capabilities describe the functions that Network Security
   Functions (NSFs) can provide for security policy enforcement.
   Security Capabilities are independent of the actual security policy
   that will implement the functionality of the NSF.

   Every NSF SHOULD be described with the set of capabilities it offers.
   Security Capabilities enable security functionality to be described
   in a vendor-neutral manner.  Security Capabilities are a market
   enabler, providing a way to define customized security protection by
   unambiguously describing the security features offered by a given
   NSF.  Note that this YANG data model forms the basis of the NSF
   Monitoring Interface YANG data model
   [I-D.ietf-i2nsf-nsf-monitoring-data-model] and the NSF-Facing
   Interface YANG data model [I-D.ietf-i2nsf-nsf-facing-interface-dm].

   This document provides an information model and the corresponding
   YANG data model [RFC6020][RFC7950] that defines the capabilities of
   NSFs to centrally manage the capabilities of those NSFs.  The NSFs
   can register their own capabilities into a Network Operator
   Management (Mgmt) System (i.e., Security Controller) with this YANG
   data model through the registration interface [RFC8329].  With the
   database of the capabilities of those NSFs that are maintained
   centrally, those NSFs can be more easily managed [RFC8329].

   This YANG data model uses an "Event-Condition-Action" (ECA) policy
   model that is used as the basis for the design of I2NSF Policy as
   described in [RFC8329] and Section 3.1.  The "ietf-i2nsf-capability"
   YANG module defined in this document provides the following features:

   *  Definition for event capabilities of network security functions.




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   *  Definition for condition capabilities of network security
      functions.

   *  Definition for action capabilities of network security functions.

   *  Definition for resolution strategy capabilities of network
      security functions.

   *  Definition for default action capabilities of network security
      functions.

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   This document uses the terminology described in [RFC8329].

   This document follows the guidelines of [RFC8407], uses the common
   YANG types defined in [RFC6991], and adopts the Network Management
   Datastore Architecture (NMDA).  The meaning of the symbols in tree
   diagrams is defined in [RFC8340].

3.  Information Model of I2NSF NSF Capability

   This section provides the I2NSF Capability Information Model (CapIM).
   A CapIM is a formalization of the functionality that an NSF
   advertises.  This enables the precise specification of what an NSF
   can do in terms of security policy enforcement, so that computer-
   based tasks can unambiguously refer to, use, configure, and manage
   NSFs.  Capabilities MUST be defined in a vendor- and technology-
   independent manner (i.e., regardless of the differences among vendors
   and individual products).

   Humans can refer to categories of security controls and understand
   each other.  For instance, network security experts agree on what is
   meant by the terms "NAT", "filtering", and "VPN concentrator".  As a
   further example, network security experts unequivocally refer to
   "packet filters" as stateless devices that allow or deny packet
   forwarding based on various conditions (e.g., source and destination
   IP addresses, source and destination ports, and IP protocol type
   fields) [Alshaer].






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   However, more information is required in case of other devices, like
   stateful firewalls or application layer filters.  These devices
   filter packets or communications, but there are differences in the
   packets and communications that they can categorize and the states
   they maintain.  Humans deal with these differences by asking more
   questions to determine the specific category and functionality of the
   device.  Machines can follow a similar approach, which is commonly
   referred to as question-answering [Hirschman].  In this context, the
   CapIM and the derived data model can provide important and rich
   information sources.

   Analogous considerations can be applied for channel protection
   protocols, where we all understand that they will protect packets by
   means of symmetric algorithms whose keys could have been negotiated
   with asymmetric cryptography, but they may work at different layers
   and support different algorithms and protocols.  To ensure
   protection, these protocols apply integrity, optionally
   confidentiality, anti-reply protections, and authentication.

   The CapIM is intended to clarify these ambiguities by providing a
   formal description of NSF functionality.  The set of functions that
   are advertised MAY be restricted according to the privileges of the
   user or application that is viewing those functions.  I2NSF
   Capabilities enable unambiguous specification of the security
   capabilities available in a (virtualized) networking environment, and
   their automatic processing by means of computer-based techniques.

   This CapIM includes enabling a security controller in an I2NSF
   framework [RFC8329] to properly identify and manage NSFs, and allow
   NSFs to properly declare their functionality through a Developer's
   Management System (DMS) [RFC8329], so that they can be used in the
   correct way.

3.1.  Design Principles and ECA Policy Model

   This document defines an information model for representing NSF
   capabilities.  Some basic design principles for security capabilities
   and the systems that manage them are:

   *  Independence: Each security capability SHOULD be an independent
      function, with minimum overlap or dependency on other
      capabilities.  This enables each security capability to be
      utilized and assembled together freely.  More importantly, changes
      to one capability SHOULD NOT affect other capabilities.  This
      follows the Single Responsibility Principle [Martin] [OODSRP].

   *  Abstraction: Each capability MUST be defined in a vendor-
      independent manner.



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   *  Advertisement: Registration Interface
      [I-D.ietf-i2nsf-registration-interface-dm] MUST be used to
      advertise and register the capabilities of each NSF.  This same
      interface MUST be used by other I2NSF Components to determine what
      Capabilities are currently available to them.

   *  Execution: NSF-Facing Interface
      [I-D.ietf-i2nsf-nsf-facing-interface-dm] and NSF Monitoring
      Interface [I-D.ietf-i2nsf-nsf-monitoring-data-model] MUST be used
      to configure the use of a capability into an NSF and monitor the
      NSF, respectively.  These provide a standardized ability to
      describe its functionality, and report its processing results,
      respectively.  These facilitate multi-vendor interoperability.

   *  Automation: The system MUST have the ability to auto-discover,
      auto-negotiate, and auto-update its security capabilities (i.e.,
      without human intervention).  These features are especially useful
      for the management of a large number of NSFs.  They are essential
      for adding smart services (e.g., refinement, analysis, capability
      reasoning, and optimization) to the security scheme employed.
      These features are supported by many design patterns, including
      the Observer Pattern [OODOP], the Mediator Pattern [OODMP], and a
      set of Message Exchange Patterns [Hohpe].  Registration Interface
      [I-D.ietf-i2nsf-registration-interface-dm] can register the
      capabilities of NSFs with the security controller from the request
      of Developer's Management System providing NSFs and the
      corresponding security capabilities.  Also, this interface can
      send a query to Developer's Management System in order to find an
      NSF to satisfy the requested security capability from the security
      controller that receives a security policy.

   *  Scalability: The management system SHOULD have the capability to
      scale up/down or scale in/out.  Thus, it can meet various
      performance requirements derived from changeable network traffic
      or service requests.  In addition, security capabilities that are
      affected by scalability changes SHOULD support reporting
      statistics to the security controller to assist its decision on
      whether it needs to invoke scaling or not.  NSF Monitoring
      Interface [I-D.ietf-i2nsf-nsf-monitoring-data-model] can observe
      the performance of NSFs to let the security controller decide
      scalability changes of the NSFs.

   Based on the above principles, this document defines a capability
   model that enables an NSF to register (and hence advertise) its set
   of capabilities that other I2NSF Components can use.  These
   capabilities MUST have their access control restricted by a policy;
   this is out of scope for this document.  The set of capabilities
   provided by a given set of NSFs unambiguously defines the security



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   services offered by the set of NSFs used.  The security controller
   can compare the requirements of users and applications with the set
   of capabilities that are currently available in order to choose which
   capabilities of which NSFs are needed to meet those requirements.
   Note that this choice is independent of vendor, and instead relies
   specifically on the capabilities (i.e., the description) of the
   functions provided.

   Furthermore, NSFs are subject to the updates of security capabilities
   and software to cope with newly found security attacks or threats,
   hence new capabilities may be created, and/or existing capabilities
   may be updated (e.g., by updating its signature and algorithm).  New
   capabilities may be sent to and stored in a centralized repository,
   or stored separately in a vendor's local repository.  In either case,
   Registration Interface can facilitate this update process to
   Developer's Management System to let the security controller update
   its repository for NSFs and their security capabilities.

   The "Event-Condition-Action" (ECA) policy model in [RFC8329] is used
   as the basis for the design of the capability model; The following
   three terms define the structure and behavior of an I2NSF imperative
   policy rule:

   *  Event: An Event is defined as any important occurrence in time of
      a change in the system being managed, and/or in the environment of
      the system being managed.  When used in the context of I2NSF
      Policy Rules, it is used to determine whether the condition clause
      of an I2NSF Policy Rule can be evaluated or not.  Examples of an
      I2NSF Event include time and user actions (e.g., logon, logoff,
      and actions that violate an ACL).

   *  Condition: A condition is defined as 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 determine
      whether or not the set of actions in that (imperative) I2NSF
      Policy Rule can be executed or not.  Examples of I2NSF conditions
      include matching attributes of a packet or flow, and comparing the
      internal state of an NSF with a desired state.

   *  Action: An action is used to control and monitor aspects of NSFs
      to handle packets or flows when the event and condition clauses
      are satisfied.  NSFs provide security functions by executing
      various Actions.  Examples of I2NSF actions include providing
      intrusion detection and/or protection, web and flow filtering, and
      deep packet inspection for packets and flows.






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   An I2NSF Policy Rule is made up of three clauses: an Event clause, a
   Condition clause, and an Action clause.  This structure is also
   called an ECA (Event-Condition-Action) Policy Rule.  A Boolean clause
   is a logical statement that evaluates to either TRUE or FALSE.  It
   may be made up of one or more terms; if more than one term is
   present, then each term in the Boolean clause is combined using
   logical connectives (i.e., AND, OR, and NOT).

   An I2NSF ECA Policy Rule has the following semantics:

      IF <event-clause> is TRUE

         IF <condition-clause> is TRUE

            THEN execute <action-clause> [constrained by metadata]

         END-IF

      END-IF

   Technically, the "Policy Rule" is really a container that aggregates
   the above three clauses, as well as metadata, which describe the
   characteristics and behaviors of a capability (or an NSF).
   Aggregating metadata enables a business logic to be used to prescribe
   a behavior.  For example, suppose a particular ECA Policy Rule
   contains three actions (A1, A2, and A3, in that order).  Action A2
   has a priority of 10; actions A1 and A3 have no priority specified.
   Then, metadata may be used to restrict the set of actions that can be
   executed when the event and condition clauses of this ECA Policy Rule
   are evaluated to be TRUE; two examples are: (1) only the first action
   (A1) is executed, and then the policy rule returns to its caller, or
   (2) all actions are executed, starting with the highest priority.

   The above ECA policy model is very general and easily extensible.

3.2.  Conflict, Resolution Strategy and Default Action

   Formally, two I2NSF Policy Rules conflict with each other if:

   *  the Event Clauses of each evaluate to TRUE;

   *  the Condition Clauses of each evaluate to TRUE;

   *  the Action Clauses affect the same object in different ways.

   For example, if we have two Policy Rules called R1 and R2 in the same
   Policy:




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      R1: During 8am-6pm, if traffic is external, then run through
      firewall

      R2: During 7am-8pm, run anti-virus

   There is no conflict between the two policy rules R1 and R2, since
   the actions are different.  However, consider these two rules called
   R3 and R4:

      R3: During 9am-6pm, allow John to access social networking service
      websites

      R4: During 9am-6pm, disallow all users to access social networking
      service websites

   The two policy rules R3 and R4 are now in conflict, between the hours
   of 9am and 6pm, because the actions of R3 and R4 are different and
   apply to the same user (i.e., John).

   Conflicts theoretically compromise the correct functioning of
   devices.  However, NSFs have been designed to cope with these issues.
   Since conflicts are originated by simultaneously matching rules, an
   additional process decides the action to be applied, e.g., among the
   actions which the matching rule would have enforced.  This process is
   described by means of a resolution strategy for conflicts.  The
   finding and handling of conflicted matching rules is performed by
   resolution strategies in the security controller.  The implementation
   of such resolution strategies is out of scope for I2NSF.

   On the other hand, it may happen that, if an event is caught, none of
   the policy rules matches the condition.  Note that a packet or flow
   is handled only when it matches both the event and condition of a
   policy rule according to the ECA policy model.  As a simple case, no
   condition in the rules may match a packet arriving at the border
   firewall.  In this case, the packet is usually dropped, that is, the
   firewall has a default behavior of packet dropping in order to manage
   the cases that are not covered by specific rules.

   Therefore, this document introduces two further capabilities for an
   NSF to handle security policy conflicts with resolution strategies
   and enforce a default action if no rules match.

   *  Resolution Strategies: They can be used to specify how to resolve
      conflicts that occur between the actions of the same or different
      policy rules that are matched and contained in this particular
      NSF;





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   *  Default Action: It provides the default behavior to be executed
      when there are no other alternatives.  This action can be either
      an explicit action or a set of actions.

4.  Overview of YANG Data Model

   This section provides an overview of how the YANG data model can be
   used in the I2NSF framework described in [RFC8329].  Figure 1 shows
   the capabilities (e.g., firewall and web filter) of NSFs in the I2NSF
   Framework.  As shown in this figure, a Developer's Management System
   (DMS) can register NSFs and their capabilities with a Security
   Controller.  To register NSFs in this way, the DMS utilizes the
   standardized capability YANG data model in this document through the
   I2NSF Registration Interface [RFC8329].  That is, this Registration
   Interface uses the YANG module described in this document to describe
   the capabilities of an NSF that is registered with the Security
   Controller.  As described in [RFC8192], with the usage of
   Registration Interface and the YANG module in this document, the NSFs
   manufactured by multiple vendors can be managed together by the
   Security Controller in a centralized way and be updated dynamically
   by each vendor as the NSF has software or hardware updates.

   In Figure 1, a new NSF at a Developer's Management System has
   capabilities of Firewall (FW) and Web Filter (WF), which are denoted
   as (Cap = {FW, WF}), to support Event-Condition-Action (ECA) policy
   rules where 'E', 'C', and 'A' mean "Event", "Condition", and
   "Action", respectively.  The condition involves IPv4 or IPv6
   datagrams, and the action includes "Allow" and "Deny" for those
   datagrams.

   Note that the NSF-Facing Interface [RFC8329] is used by the Security
   Controller to configure the security policy rules of NSFs (e.g.,
   firewall and Distributed-Denial-of-Service (DDoS) attack mitigator)
   with the capabilities of the NSFs registered with the Security
   Controller.
















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      +------------------------------------------------------+
      |  I2NSF User (e.g., Overlay Network Mgmt, Enterprise  |
      |  Network Mgmt, another network domain's mgmt, etc.)  |
      +--------------------+---------------------------------+
          I2NSF            ^
 Consumer-Facing Interface |
                           |
                           v                 I2NSF
         +-----------------+------------+  Registration +-------------+
         | Network Operator Mgmt System |   Interface   | Developer's |
         | (i.e., Security Controller)  |<------------->| Mgmt System |
         +-----------------+------------+               +-------------+
                           ^                                New NSF
                           |                          Cap = {FW, WF}
             I2NSF         |                          E = {}
      NSF-Facing Interface |                          C = {IPv4, IPv6}
                           |                          A = {Allow, Deny}
                           v
      +---------------+----+------------+-----------------+
      |               |                 |                 |
  +---+---+       +---+---+         +---+---+         +---+---+
  | NSF-1 |  ...  | NSF-m |         | NSF-1 |   ...   | NSF-n |
  +-------+       +-------+         +-------+         +-------+
    NSF-1           NSF-m             NSF-1             NSF-n
 Cap = {FW, WF}    Cap = {FW, WF}    Cap = {FW, WF}    Cap = {FW, WF}
 E = {}            E = {user}        E = {dev}         E = {time}
 C = {IPv4}        C = {IPv6}        C = {IPv4, IPv6}  C = {IPv4}
 A = {Allow, Deny} A = {Allow, Deny} A = {Allow, Deny} A = {Allow, Deny}

  Developer's Mgmt System A           Developer's Mgmt System B


          Figure 1: Capabilities of NSFs in I2NSF Framework

   A use case of an NSF with the capabilities of firewall and web filter
   is described as follows.

   *  If a network administrator wants to apply security policy rules to
      block malicious users with firewall and web filter, it is a
      tremendous burden for a network administrator to apply all of the
      needed rules to NSFs one by one.  This problem can be resolved by
      managing the capabilities of NSFs as described in this document.

   *  If a network administrator wants to block IPv4 or IPv6 packets
      from malicious users, the network administrator sends a security
      policy rule to block the users to the Network Operator Management
      System (i.e., Security Controller) using the I2NSF Consumer-Facing
      Interface.



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   *  When the Network Operator Management System receives the security
      policy rule, it automatically sends that security policy rule to
      appropriate NSFs (i.e., NSF-m in Developer's Management System A
      and NSF-1 in Developer's Management System B) which can support
      the capabilities (i.e., IPv6).  This lets an I2NSF User not
      consider which specific NSF(s) will work for the security policy
      rule.

   *  If NSFs encounter the suspicious IPv4 or IPv6 packets of malicious
      users, they can filter the packets out according to the configured
      security policy rule.  Therefore, the security policy rule against
      the malicious users' packets can be automatically applied to
      appropriate NSFs without human intervention.

5.  YANG Tree Diagram

   This section shows a YANG tree diagram of capabilities of network
   security functions, as defined in the Section 3.

5.1.  Network Security Function (NSF) Capabilities

   This section explains a YANG tree diagram of NSF capabilities and its
   features.  Figure 2 shows a YANG tree diagram of NSF capabilities.
   The NSF capabilities in the tree include time capabilities, event
   capabilities, condition capabilities, action capabilities, resolution
   strategy capabilities, and default action capabilities.  Those
   capabilities can be tailored or extended according to a vendor's
   specific requirements.  Refer to the NSF capabilities information
   model for detailed discussion in Section 3.






















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   module: ietf-i2nsf-capability
     +--rw nsf* [nsf-name]
        +--rw nsf-name                            string
        +--rw directional-capabilities*           identityref
        +--rw event-capabilities
        |  +--rw system-event-capability*   identityref
        |  +--rw system-alarm-capability*   identityref
        |  +--rw time-capabilities*         identityref
        +--rw condition-capabilities
        |  +--rw generic-nsf-capabilities
        |  |  +--rw ethernet-capability*   identityref
        |  |  +--rw ipv4-capability*       identityref
        |  |  +--rw ipv6-capability*       identityref
        |  |  +--rw icmpv4-capability*     identityref
        |  |  +--rw icmpv6-capability*     identityref
        |  |  +--rw tcp-capability*        identityref
        |  |  +--rw udp-capability*        identityref
        |  |  +--rw sctp-capability*       identityref
        |  |  +--rw dccp-capability*       identityref
        |  +--rw advanced-nsf-capabilities
        |  |  +--rw anti-ddos-capability*              identityref
        |  |  +--rw ips-capability*                    identityref
        |  |  +--rw anti-virus-capability*             identityref
        |  |  +--rw url-capability*                    identityref
        |  |  +--rw voip-volte-filtering-capability*   identityref
        |  +--rw context-capabilities
        |     +--rw application-filter-capabilities*   identityref
        |     +--rw target-capabilities*               identityref
        |     +--rw user-condition-capabilities*       identityref
        |     +--rw geography-capabilities*            identityref
        +--rw action-capabilities
        |  +--rw ingress-action-capability*   identityref
        |  +--rw egress-action-capability*    identityref
        |  +--rw log-action-capability*       identityref
        +--rw resolution-strategy-capabilities*   identityref
        +--rw default-action-capabilities*        identityref


      Figure 2: YANG Tree Diagram of Capabilities of Network Security
                                 Functions

   The data model in this document provides identities for the
   capabilities of NSFs.  Every identity in the data model represents
   the capability of an NSF.  Each identity is explained in the
   description of the identity.






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   Event capabilities are used to specify the capabilities that describe
   an event that would trigger the evaluation of the condition clause of
   the I2NSF Policy Rule.  The defined event capabilities are system
   event, system alarm, and time.  Time capabilities are used to specify
   the capabilities which describe when to execute the I2NSF policy
   rule.  The time capabilities are defined in terms of absolute time
   and periodic time.  The absolute time means the exact time to start
   or end.  The periodic time means repeated time like day, week, month,
   or year.

   Condition capabilities are used to specify capabilities of 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
   determine whether a set of actions needs to be executed or not so
   that an imperative I2NSF policy rule can be executed.  In this
   document, two kinds of condition capabilities are used to classify
   different capabilities of NSFs such as generic-nsf-capabilities and
   advanced-nsf-capabilities.  First, the generic-nsf-capabilities
   define NSFs that operate on packet header for layer 2 (i.e., Ethernet
   capability), layer 3 (i.e., IPv4 capability, IPv6 capability, ICMPv4
   capability, and ICMPv6 capability.), and layer 4 (i.e., TCP
   capability, UDP capability, SCTP capability, and DCCP capability).
   Second, the advanced-nsf-capabilities define NSFs that operate on
   features different from the generic-nsf-capabilities, e.g., the
   payload, cross flow state, application layer, traffic statistics,
   network behavior, etc.  This document defines the advanced-nsf into
   two categories such as content-security-control and attack-
   mitigation-control.

   *  Content security control is an NSF that evaluates the payload of a
      packet, such as Intrusion Prevention System (IPS), URL-Filtering,
      Antivirus, and VoIP/VoLTE Filter.

   *  Attack mitigation control is an NSF that mitigates an attack such
      as anti-DDoS (DDoS-mitigator).

   The advanced-nsf can be extended with other types of NSFs.  This
   document only provides five advanced-nsf capabilities, i.e., IPS
   capability, URL-Filtering capability, Antivirus capability, VoIP/
   VoLTE Filter capability, and Anti-DDoS capability.  Note that VoIP
   and VoLTE are merged into a single capability in this document
   because VoIP and VoLTE use the Session Initiation Protocol (SIP)
   [RFC3261] for a call setup.  See Section 3.1 for more information
   about the condition in the ECA policy model.

   The context capabilities provide extra information for the condition.
   The given context conditions are application filter, target, user
   condition, and geography location.  The application filter capability



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   is capability in matching the packet based on the application
   protocol, such as HTTP, HTTPS, FTP, etc.  The target capability is
   capability in matching the type of the target devices, such as PC,
   IoT, Network Infrastructure devices, etc.  The user condition is
   capability in matching the users of the network by mapping each user
   ID to an IP address.  Users can be combined into one group.  The
   geography location capability is capability in matching the
   geographical location of a source or destination of a packet.

   Action capabilities are used to specify the capabilities that
   describe the control and monitoring aspects of flow-based NSFs when
   the event and condition clauses are satisfied.  The action
   capabilities are defined as ingress-action capability, egress-action
   capability, and log-action capability.  See Section 3.1 for more
   information about the action in the ECA policy model.  Also, see
   Section 7.2 (NSF-Facing Flow Security Policy Structure) in [RFC8329]
   for more information about the ingress and egress actions.  In
   addition, see Section 9.1 (Flow-Based NSF Capability
   Characterization) in [RFC8329] and Section 7.5 (NSF Logs) in
   [I-D.ietf-i2nsf-nsf-monitoring-data-model] for more information about
   logging at NSFs.

   Resolution strategy capabilities are used to specify the capabilities
   that describe conflicts that occur between the actions of the same or
   different policy rules that are matched and contained in this
   particular NSF.  The resolution strategy capabilities are defined as
   First Matching Rule (FMR), Last Matching Rule (LMR), Prioritized
   Matching Rule (PMR), Prioritized Matching Rule with Errors (PMRE),
   and Prioritized Matching Rule with No Errors (PMRN).  See Section 3.2
   for more information about the resolution strategy.

   Default action capabilities are used to specify the capabilities that
   describe how to execute I2NSF policy rules when no rule matches a
   packet.  The default action capabilities are defined as pass, drop,
   rate-limit, and mirror.  See Section 3.2 for more information about
   the default action.

6.  YANG Data Model of I2NSF NSF Capability

   This section introduces a YANG module for NSFs' capabilities, as
   defined in the Section 3.

   It makes references to

   *  [RFC0768]

   *  [RFC0791]




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   *  [RFC0792]

   *  [RFC0854]

   *  [RFC0959]

   *  [RFC1939]

   *  [RFC2474]

   *  [RFC2818]

   *  [RFC3168]

   *  [RFC3261]

   *  [RFC9051]

   *  [RFC4250]

   *  [RFC4340]

   *  [RFC4443]

   *  [RFC4766]

   *  [RFC4960]

   *  [RFC5103]

   *  [RFC5321]

   *  [RFC5595]

   *  [RFC6335]

   *  [RFC6437]

   *  [RFC6691]

   *  [RFC6864]

   *  [RFC7230]

   *  [RFC7231]

   *  [RFC7323]




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   *  [RFC8200]

   *  [RFC8329]

   *  [RFC8805]

   *  [IEEE802.3-2018]

   *  [IANA-Protocol-Numbers]

   *  [I-D.ietf-tcpm-rfc793bis]

   *  [I-D.ietf-tcpm-accurate-ecn]

   *  [I-D.ietf-tsvwg-udp-options]

   *  [I-D.ietf-i2nsf-nsf-monitoring-data-model]

   <CODE BEGINS> file "ietf-i2nsf-capability@2021-11-13.yang"
   module ietf-i2nsf-capability {
     yang-version 1.1;
     namespace
       "urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability";
     prefix
       nsfcap;

     organization
       "IETF I2NSF (Interface to Network Security Functions)
        Working Group";

     contact
       "WG Web: <https://tools.ietf.org/wg/i2nsf>
        WG List: <mailto:i2nsf@ietf.org>

        Editor: Susan Hares
        <mailto:shares@ndzh.com>

        Editor: Jaehoon (Paul) Jeong
        <mailto:pauljeong@skku.edu>

        Editor: Jinyong (Tim) Kim
        <mailto:timkim@skku.edu>

        Editor: Robert Moskowitz
        <mailto:rgm@htt-consult.com>

        Editor: Qiushi Lin
        <mailto:linqiushi@huawei.com>



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        Editor: Patrick Lingga
        <mailto:patricklink@skku.edu>";

     description
       "This module is a YANG module for I2NSF Network Security
        Functions (NSFs)'s Capabilities.

        Copyright (c) 2021 IETF Trust and the persons identified as
        authors of the code. All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject to
        the license terms contained in, the Simplified BSD License set
        forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
        for full legal notices.";

     // RFC Ed.: replace XXXX with an actual RFC number and remove
     // this note.

     revision "2021-11-13"{
       description "Initial revision.";
       reference
         "RFC XXXX: I2NSF Capability YANG Data Model";

       // RFC Ed.: replace XXXX with an actual RFC number and remove
       // this note.
     }

     /*
      * Identities
      */

     identity event {
       description
         "Base identity for I2NSF events.";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - Event";
     }

     identity system-event {
       base event;
       description



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         "Identity for system event";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - System event";
     }

     identity system-alarm {
       base event;
       description
         "Identity for system alarm";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - System alarm";
     }

     identity time {
       base event;
       description
         "Identity for time capabilities";
     }

     identity access-violation {
       base system-event;
       description
         "Identity for access violation event";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - System event for access
          violation";
     }

     identity configuration-change {
       base system-event;
       description
         "Identity for configuration change event";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - System event for configuration
          change";
     }

     identity memory-alarm {
       base system-alarm;
       description
         "Identity for memory alarm. Alarm when memory usage
         exceeds a threshold.";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF



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          Monitoring YANG Data Model - System alarm for memory";
     }

     identity cpu-alarm {
       base system-alarm;
       description
         "Identity for CPU alarm. Alarm when CPU usage
         exceeds a threshold.";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - System alarm for CPU";
     }

     identity disk-alarm {
       base system-alarm;
       description
         "Identity for disk alarm. Alarm when disk usage
         exceeds a threshold.";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - System alarm for disk";
     }

     identity hardware-alarm {
       base system-alarm;
       description
         "Identity for hardware alarm. Alarm when a hardware failure
         or hardware degradation occurs.";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - System alarm for hardware";
     }

     identity interface-alarm {
       base system-alarm;
       description
         "Identity for interface alarm. Alarm when interface usage
         exceeds a threshold.";
       reference
         "draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF NSF
          Monitoring YANG Data Model - System alarm for interface";
     }

     identity absolute-time {
       base time;
       description
         "absolute time capabilities.
          If a network security function has the absolute time



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          capability, the network security function supports
          rule execution according to absolute time.";
     }

     identity periodic-time {
       base time;
       description
         "periodic time capabilities.
          If a network security function has the periodic time
          capability, the network security function supports
          rule execution according to periodic time.";
     }

     identity target-device {
       description
         "Identity for target condition capability. The capability for
          matching the target device type.";
     }

     identity computer {
       base target-device;
       description
         "Identity for computer such as personal computer (PC)
          and server";
     }

     identity mobile-phone {
       base target-device;
       description
         "Identity for mobile-phone such as smartphone and
          cellphone";
     }

     identity voip-volte-phone {
       base target-device;
       description
         "Identity for voip-volte-phone";
     }

     identity tablet {
       base target-device;
       description
         "Identity for tablet";
     }

     identity network-infrastructure-device {
       base target-device;
       description



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         "Identity for network infrastructure devices
          such as switch, router, and access point";
     }

     identity iot {
       base target-device;
       description
         "Identity for IoT (Internet of Things)";
     }

     identity ot {
       base target-device;
       description
         "Identity for Operational Technology";
     }

     identity vehicle {
       base target-device;
       description
         "Identity for vehicle that connects to and shares
          data through the Internet";
     }

     identity user-condition {
       description
         "Base identity for user condition capability. This is the
          capability of mapping user(s) into their corresponding IP
          address";
     }

     identity user {
       base user-condition;
       description
         "Identity for user condition capability.
          A user (e.g., employee) can be mapped to an IP address of
          a computing device (e.g., computer, laptop, and virtual
          machine) which the user is using.";
     }

     identity group {
       base user-condition;
       description
         "Identity for group condition capability.
          A group (e.g., employees) can be mapped to multiple IP
          addresses of computing devices (e.g., computers, laptops,
          and virtual machines) which the group is using.";
     }




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     identity geography-location {
       description
         "Identity for geography condition capability";
       reference
         "RFC 8805: A Format for Self-Published IP Geolocation Feeds -
          An access control for a geographical location (i.e.,
          geolocation) that has the corresponding IP prefix.";
     }

     identity source-location {
       base geography-location;
       description
         "Identity for source geography location condition capability";
       reference
         "RFC 8805: A Format for Self-Published IP Geolocation Feeds -
          An access control for a geographical location (i.e.,
          geolocation) that has the corresponding IP prefix.";
     }

     identity destination-location {
       base geography-location;
       description
         "Identity for destination geography location condition
          capability";
       reference
         "RFC 8805: A Format for Self-Published IP Geolocation Feeds -
          An access control for a geographical location (i.e.,
          geolocation) that has the corresponding IP prefix.";
     }

     identity directional {
       description
         "Base identity for directional traffic flow capability";
       reference
         "RFC 5103: Bidirectional Flow Export Using IP Flow Information
          Export (IPFIX) - Terminology Unidirectional and Bidirectional
          Flow";
     }

     identity unidirectional {
       base directional;
       description
         "Identity for unidirectional traffic flow.";
       reference
         "RFC 5103: Bidirectional Flow Export Using IP Flow Information
          Export (IPFIX) - Terminology Unidirectional Flow";
     }




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     identity bidirectional {
       base directional;
       description
         "Identity for bidirectional traffic flow.";
       reference
         "RFC 5103: Bidirectional Flow Export Using IP Flow Information
          Export (IPFIX) - Terminology Bidirectional Flow";
     }

     identity protocol {
       description
         "Base identity for protocols";
     }

     identity ethernet {
       base protocol;
       description
         "Base identity for Ethernet protocol.";
     }

     identity source-mac-address {
       base ethernet;
       description
         "Identity for the capability of matching Media Access Control
          (MAC) source address(es) condition capability.";
       reference
         "IEEE 802.3 - 2018: IEEE Standard for Ethernet";
     }

     identity destination-mac-address {
       base ethernet;
       description
         "Identity for the capability of matching Media Access Control
          (MAC) destination address(es) condition capability.";
       reference
         "IEEE 802.3 - 2018: IEEE Standard for Ethernet";
     }

     identity ether-type {
       base ethernet;
       description
         "Identity for the capability of matching the EtherType in
          Ethernet II and Length in Ethernet 802.3 of a packet.";
       reference
         "IEEE 802.3 - 2018: IEEE Standard for Ethernet";
     }

     identity ip {



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       base protocol;
       description
         "Base identity for internet/network layer protocol,
          e.g., IPv4, IPv6, and ICMP.";
     }

     identity ipv4 {
       base ip;
       description
         "Base identity for IPv4 condition capability";
       reference
         "RFC 791: Internet Protocol";
     }

     identity ipv6 {
       base ip;
       description
         "Base identity for IPv6 condition capabilities";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification";
     }

     identity dscp {
       base ipv4;
       base ipv6;
       description
         "Identity for the capability of matching IPv4 annd IPv6
          Differentiated Services Codepoint (DSCP) condition";
       reference
         "RFC 791: Internet Protocol - Type of Service
          RFC 2474: Definition of the Differentiated
          Services Field (DS Field) in the IPv4 and
          IPv6 Headers
          RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification - Traffic Class";
     }

     identity length {
       base ipv4;
       base ipv6;
       description
         "Identity for the capability of matching IPv4 Total Length
          header field or IPv6 Payload Length header field.

          IPv4 Total Length is the length of datagram, measured in
          octets, including internet header and data.




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          IPv6 Payload Length is the length of the IPv6 payload, i.e.,
          the rest of the packet following the IPv6 header, measured in
          octets.";
       reference
         "RFC 791: Internet Protocol - Total Length
          RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification - Payload Length";
     }

     identity ttl {
       base ipv4;
       base ipv6;
       description
         "Identity for the capability of matching IPv4 Time-To-Live
          (TTL) or IPv6 Hop Limit.";
       reference
         "RFC 791: Internet Protocol - Time To Live (TTL)
          RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification - Hop Limit";
     }

     identity next-header {
       base ipv4;
       base ipv6;
       description
         "Identity for the capability of matching IPv4 Protocol Field or
          equivalent to IPv6 Next Header.";
       reference
         "IANA Website: Assigned Internet Protocol Numbers
          - Protocol Number for IPv4
          RFC 791: Internet Protocol - Protocol
          RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification - Next Header";
     }

     identity source-address {
       base ipv4;
       base ipv6;
       description
         "Identity for the capability of matching IPv4 or IPv6 source
          address(es) condition capability.";
       reference
         "RFC 791: Internet Protocol - Address
          RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification - Source Address";
     }

     identity destination-address {



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       base ipv4;
       base ipv6;
       description
         "Identity for the capability of matching IPv4 or IPv6
          destination address(es) condition capability.";
       reference
         "RFC 791: Internet Protocol - Address
          RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification - Destination Address";
     }

     identity flow-direction {
       base ipv4;
       base ipv6;
       description
         "Identity for flow direction of matching IPv4/IPv6 source
          or destination address(es) condition capability where a flow's
          direction is either unidirectional or bidirectional";
       reference
         "RFC 791: Internet Protocol
          RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification";
     }

     identity header-length {
       base ipv4;
       description
         "Identity for matching IPv4 header-length
         condition capability";
       reference
         "RFC 791: Internet Protocol - Header Length";
     }

     identity identification {
       base ipv4;
       description
         "Identity for IPv4 identification condition capability.
          IPv4 ID field is used for fragmentation and reassembly.";
       reference
         "RFC 791: Internet Protocol - Identification
          RFC 6864: Updated Specification of the IPv4 ID Field -
          Fragmentation and Reassembly";
     }

     identity fragment-flags {
       base ipv4;
       description
         "Identity for IPv4 fragment flags condition capability";



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       reference
         "RFC 791: Internet Protocol - Fragmentation Flags";
     }

     identity fragment-offset {
       base ipv4;
       description
         "Identity for matching IPv4 fragment offset
         condition capability";
       reference
         "RFC 791: Internet Protocol - Fragmentation Offset";
     }

     identity ipv4-options {
       base ipv4;
       description
         "Identity for IPv4 options condition capability";
       reference
         "RFC 791: Internet Protocol - Options";
     }

     identity flow-label {
       base ipv6;
       description
         "Identity for matching IPv6 flow label
         condition capability";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification - Flow Label
          RFC 6437: IPv6 Flow Label Specification";
     }

     identity header-order {
       base ipv6;
       description
         "Identity for IPv6 extension header order condition
         capability";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)
          Specification - Extension Header Order";
     }

     identity hop-by-hop {
       base ipv6;
       description
         "Identity for IPv6 hop by hop options header
         condition capability";
       reference



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         "RFC 8200: Internet Protocol, Version 6 (IPv6)

         Specification - Options";
     }

     identity routing-header {
       base ipv6;
       description
         "Identity for IPv6 routing header condition
         capability";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)
         Specification - Routing Header";
     }

     identity fragment-header {
       base ipv6;
       description
         "Identity for IPv6 fragment header condition
         capability";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)
         Specification - Fragment Header";
     }

     identity destination-options {
       base ipv6;
       description
         "Identity for IPv6 destination options condition
         capability";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)
         Specification - Destination Options";
     }

     identity icmp {
       base protocol;
       description
         "Base identity for ICMPv4 and ICMPv6 condition capability";
       reference
         "RFC 792: Internet Control Message Protocol
          RFC 4443: Internet Control Message Protocol (ICMPv6)
          for the Internet Protocol Version 6 (IPv6) Specification
          - ICMPv6";
     }

     identity icmpv4 {
       base icmp;



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       description
         "Base identity for ICMPv4 condition capability";
       reference
         "RFC 792: Internet Control Message Protocol";
     }

     identity icmpv6 {
       base icmp;
       description
         "Base identity for ICMPv6 condition capability";
       reference
         "RFC 4443: Internet Control Message Protocol (ICMPv6)
          for the Internet Protocol Version 6 (IPv6) Specification
          - ICMPv6";
     }

     identity type {
       base icmpv4;
       base icmpv6;
       description
         "Identity for ICMPv4 and ICMPv6 type condition capability";
       reference
         "RFC 792: Internet Control Message Protocol
          RFC 4443: Internet Control Message Protocol (ICMPv6)
          for the Internet Protocol Version 6 (IPv6) Specification
          - ICMPv6";
     }

     identity code {
       base icmpv4;
       base icmpv6;
       description
         "Identity for ICMPv4 and ICMPv6 code condition capability";
       reference
         "RFC 792: Internet Control Message Protocol
          RFC 4443: Internet Control Message Protocol (ICMPv6)
          for the Internet Protocol Version 6 (IPv6) Specification
          - ICMPv6";
     }

     identity transport-protocol {
       base protocol;
       description
         "Base identity for Layer 4 protocol condition capabilities,
          e.g., TCP, UDP, SCTP, and DCCP";
     }

     identity tcp {



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       base transport-protocol;
       description
         "Base identity for TCP condition capabilities";
       reference
         "draft-ietf-tcpm-rfc793bis-25: Transmission Control Protocol
          (TCP) Specification";
     }

     identity udp {
       base transport-protocol;
       description
         "Base identity for UDP condition capabilities";
       reference
         "RFC 768: User Datagram Protocol";
     }

     identity sctp {
       base transport-protocol;
       description
         "Identity for SCTP condition capabilities";
       reference
         "RFC 4960: Stream Control Transmission Protocol";
     }

     identity dccp {
       base transport-protocol;
       description
         "Identity for DCCP condition capabilities";
       reference
         "RFC 4340: Datagram Congestion Control Protocol";
     }

     identity source-port-number {
       base tcp;
       base udp;
       base sctp;
       base dccp;
       description
         "Identity for matching TCP, UDP, SCTP, and DCCP source port
          number condition capability";
       reference
         "draft-ietf-tcpm-rfc793bis-25: Transmission Control Protocol
          (TCP) Specification
          RFC 768: User Datagram Protocol
          RFC 4960: Stream Control Transmission Protocol
          RFC 4340: Datagram Congestion Control Protocol";
     }




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     identity destination-port-number {
       base tcp;
       base udp;
       base sctp;
       base dccp;
       description
         "Identity for matching TCP, UDP, SCTP, and DCCP destination
          port number condition capability";
       reference
         "draft-ietf-tcpm-rfc793bis-25: Transmission Control Protocol
          (TCP) Specification";
     }

     identity flags {
       base tcp;
       description
         "Identity for TCP control bits (flags) condition capability";
       reference
         "draft-ietf-tcpm-rfc793bis-25: Transmission Control Protocol
          (TCP) Specification - TCP Header Flags
          RFC 3168: The Addition of Explicit Congestion Notification
          (ECN) to IP - ECN-Echo (ECE) Flag and Congestion Window
          Reduced (CWR) Flag
          draft-ietf-tcpm-accurate-ecn-15: More Accurate ECN Feedback
          in TCP - ECN-Echo (ECE) Flag and Congestion Window Reduced
          (CWR) Flag";
     }

     identity tcp-options {
       base tcp;
       description
         "Identity for TCP options condition capability.";
       reference
         "draft-ietf-tcpm-rfc793bis-25: Transmission Control Protocol
          (TCP) Specification
          RFC 6691: TCP Options and Maximum Segment Size
          RFC 7323: TCP Extensions for High Performance";
     }

     identity total-length {
       base udp;
       description
         "Identity for matching UDP total-length condition capability.
          The UDP total length can be smaller than the IP transport
          length for UDP transport layer options.";
       reference
         "RFC 768: User Datagram Protocol - Total Length
          draft-ietf-tsvwg-udp-options: Transport Options for UDP";



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     }

     identity verification-tag {
       base sctp;
       description
         "Identity for range-match SCTP verification tag condition
          capability";
       reference
         "RFC 4960: Stream Control Transmission Protocol - Verification
          Tag";
     }

     identity chunk-type {
       base sctp;
       description
         "Identity for SCTP chunk type condition capability";
       reference
         "RFC 4960: Stream Control Transmission Protocol - Chunk Type";
     }

     identity service-code {
       base dccp;
       description
         "Identity for DCCP Service Code condition capabilitiy";
       reference
         "RFC 4340: Datagram Congestion Control Protocol
          RFC 5595: The Datagram Congestion Control Protocol (DCCP)
          Service Codes
          RFC 6335: Internet Assigned Numbers Authority (IANA)
          Procedures for the Management of the Service Name and
          Transport Protocol Port Number Registry - Service Code";
     }

     identity application-protocol {
       base protocol;
       description
         "Base identity for Application protocol";
     }

     identity http {
       base application-protocol;
       description
         "The identity for Hypertext Transfer Protocol.";
       reference
         "RFC 7230: Hypertext Transfer Protocol (HTTP/1.1): Message
          Syntax and Routing
          RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content";



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     }

     identity https {
       base application-protocol;
       description
         "The identity for Hypertext Transfer Protocol Secure.";
       reference
         "RFC 2818: HTTP over TLS (HTTPS)
          RFC 7230: Hypertext Transfer Protocol (HTTP/1.1): Message
          Syntax and Routing
          RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content";
     }

     identity ftp {
       base application-protocol;
       description
         "The identity for File Transfer Protocol.";
       reference
         "RFC 959: File Transfer Protocol (FTP)";
     }

     identity ssh {
       base application-protocol;
       description
         "The identity for Secure Shell (SSH) protocol.";
       reference
         "RFC 4250: The Secure Shell (SSH) Protocol";
     }

     identity telnet {
       base application-protocol;
       description
         "The identity for telnet.";
       reference
         "RFC 854: Telnet Protocol";
     }

     identity smtp {
       base application-protocol;
       description
         "The identity for Simple Mail Transfer Protocol.";
       reference
         "RFC 5321: Simple Mail Transfer Protocol (SMTP)";
     }

     identity pop3 {
       base application-protocol;



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       description
         "The identity for Post Office Protocol 3.";
       reference
         "RFC 1939: Post Office Protocol - Version 3 (POP3)";
     }

     identity imap {
       base application-protocol;
       description
         "The identity for Internet Message Access Protocol.";
       reference
         "RFC 9051: Internet Message Access Protocol (IMAP) - Version 4rev2";
     }

     identity action {
       description
         "Base identity for action capability";
     }

     identity log-action {
       base action;
       description
         "Base identity for log-action capability";
     }

     identity ingress-action {
       base action;
       description
         "Base identity for ingress-action capability";
       reference
         "RFC 8329: Framework for Interface to Network Security
          Functions - Section 7.2";
     }

     identity egress-action {
       base action;
       description
         "Base identity for egress-action capability";
       reference
         "RFC 8329: Framework for Interface to Network Security
          Functions - Section 7.2";
     }

     identity default-action {
       base action;
       description
         "Base identity for default-action capability";
     }



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     identity rule-log {
       base log-action;
       description
         "Identity for rule log-action capability.
          Log the received packet based on the rule";
     }

     identity session-log {
       base log-action;
       description
         "Identity for session log-action capability.
          Log the received packet based on the session.";
     }

     identity pass {
       base ingress-action;
       base egress-action;
       base default-action;
       description
         "Identity for pass action capability. The pass action allows
          packet or flow to go through the NSF entering or exiting the
          internal network.";
     }

     identity drop {
       base ingress-action;
       base egress-action;
       base default-action;
       description
         "Identity for drop action capability. The drop action denies
          packet to go through the NSF entering or exiting the internal
          network.";
     }

     identity mirror {
       base ingress-action;
       base egress-action;
       base default-action;
       description
         "Identity for mirror action capability. The mirror action
          copies packet and send it to the monitoring entity while still
          allow the packet or flow to go through the NSF.";
     }

     identity rate-limit {
       base ingress-action;
       base egress-action;
       base default-action;



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       description
         "Identity for rate limiting action capability. The rate limit
          action limits the number of packets or flows that can go
          through the NSF by dropping packets or flows (randomly or
          systematically).";
     }

     identity invoke-signaling {
       base egress-action;
       description
         "Identity for invoke signaling action capability";
     }

     identity tunnel-encapsulation {
       base egress-action;
       description
         "Identity for tunnel encapsulation action capability";
     }

     identity forwarding {
       base egress-action;
       description
         "Identity for forwarding action capability";
     }

     identity transformation {
       base egress-action;
       description
         "Identity for transformation action capability";
     }

     identity resolution-strategy {
       description
         "Base identity for resolution strategy capability";
     }

     identity fmr {
       base resolution-strategy;
       description
         "Identity for First Matching Rule (FMR) resolution
          strategy capability";
     }

     identity lmr {
       base resolution-strategy;
       description
         "Identity for Last Matching Rule (LMR) resolution
          strategy capability";



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     }

     identity pmr {
       base resolution-strategy;
       description
         "Identity for Prioritized Matching Rule (PMR) resolution
          strategy capability";
     }

     identity pmre {
       base resolution-strategy;
       description
         "Identity for Prioritized Matching Rule with Errors (PMRE)
          resolution strategy capability";
     }

     identity pmrn {
       base resolution-strategy;
       description
         "Identity for Prioritized Matching Rule with No Errors (PMRN)
          resolution strategy capability";
     }

     identity advanced-nsf {
       description
         "Base identity for advanced Network Security Function (NSF)
          capability.";
     }

     identity content-security-control {
       base advanced-nsf;
       description
         "Base identity for content security control. Content security
          control is an NSF that evaluates a packet's payload such as
          Intrusion Prevention System (IPS), URL-Filtering, Antivirus,
          and VoIP/VoLTE Filter.";
     }

     identity attack-mitigation-control {
       base advanced-nsf;
       description
         "Base identity for attack mitigation control. Attack mitigation
          control is an NSF that mitigates an attack such as anti-DDoS
          or DDoS-mitigator.";
     }

     identity ips {
       base content-security-control;



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       description
         "Base identity for IPS (Intrusion Prevention System) capability
          that prevents malicious activity within a network";
     }

     identity url-filtering {
       base content-security-control;
       description
         "Base identity for url filtering capability that limits access
          by comparing the web traffic's URL with the URLs for web
          filtering in a database";
     }

     identity anti-virus {
       base content-security-control;
       description
         "Base identity for anti-virus capability to protect the network
          by detecting and removing viruses.";
     }

     identity voip-volte-filtering {
       base content-security-control;
       description
         "Base identity for advanced NSF VoIP/VoLTE Security Service
          capability to filter the VoIP/VoLTE packets or flows.";
       reference
         "RFC 3261: SIP: Session Initiation Protocol";
     }

     identity anti-ddos {
       base attack-mitigation-control;
       description
         "Base identity for advanced NSF Anti-DDoS Attack or DDoS
          Mitigator capability.";
     }

     identity packet-rate {
       base anti-ddos;
       description
         "Identity for advanced NSF Anti-DDoS detecting Packet Rate
          Capability where a packet rate is defined as the arrival rate
          of Packets toward a victim destination node.  The NSF with
          this capability can detect the incoming packet rate and create
          an alert if the rate exceeds the threshold.";

     }

     identity flow-rate {



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       base anti-ddos;
       description
         "Identity for advanced NSF Anti-DDoS detecting Flow Rate
          Capability where a flow rate is defined as the arrival rate of
          flows towards a victim destination node.  The NSF with this
          capability can detect the incoming flow rate and create an
          alert if the rate exceeds the threshold.";
     }

     identity byte-rate {
       base anti-ddos;
       description
         "Identity for advanced NSF Anti-DDoS detecting Byte Rate
          Capability where a byte rate is defined as the arrival rate of
          Bytes toward a victim destination node.  The NSF with this
          capability can detect the incoming byte rate and create an
          alert if the rate exceeds the threshold.";
     }

     identity signature-set {
       base ips;
       description
         "Identity for the capability of IPS to set the signature.
          Signature is a set of rules to detect an intrusive activity.";
       reference
         "RFC 4766:  Intrusion Detection Message Exchange Requirements -
          Section 2.2.13";
     }

     identity exception-signature {
       base ips;
       description
         "Identity for the capability of IPS to exclude signatures from
          detecting the intrusion.";
       reference
         "RFC 4766:  Intrusion Detection Message Exchange Requirements -
          Section 2.2.13";
     }

     identity detect {
       base anti-virus;
       description
         "Identity for advanced NSF Antivirus capability to detect
          viruses using a security profile. The security profile is used
          to scan threats, such as virus, malware, and spyware. The NSF
          should be able to update the security profile.";
     }




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     identity exception-files {
       base anti-virus;
       description
         "Identity for advanced NSF Antivirus capability to exclude a
          certain file type or name from detection.";
     }

     identity pre-defined {
       base url-filtering;
       description
         "Identity for pre-defined URL Database condition capability.
          where URL database is a public database for URL filtering.";
     }

     identity user-defined {
       base url-filtering;
       description
         "Identity for user-defined URL Database condition capability.
          that allows a users manual addition of URLs for URL
          filtering.";
     }

     identity call-id {
       base voip-volte-filtering;
       description
         "Identity for advanced NSF VoIP/VoLTE Call Identifier (ID)
          capability.";
     }

     identity user-agent {
       base voip-volte-filtering;
       description
         "Identity for advanced NSF VoIP/VoLTE User Agent capability.";
     }

     /*
      *  Grouping
      */

     grouping nsf-capabilities {
       description
         "Network Security Function (NSF) Capabilities";
       reference
         "RFC 8329: Framework for Interface to Network Security
          Functions - I2NSF Flow Security Policy Structure.";

       leaf-list directional-capabilities {
         type identityref {



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           base directional;
         }
         description
           "The capability of an NSF for handling directional traffic
            flow (i.e., unidirectional or bidirectional traffic flow).";
       }

       container event-capabilities {
         description
           "Capabilities of events.
            If a network security function has the event capabilities,
            the network security function supports rule execution
            according to system event and system alarm.";

         reference
           "RFC 8329: Framework for Interface to Network Security
            Functions - Section 7.
            draft-ietf-i2nsf-nsf-monitoring-data-model-09: I2NSF
            NSF Monitoring YANG Data Model - System Alarm and
            System Events.";

         leaf-list system-event-capability {
           type identityref {
             base system-event;
           }
           description
             "System event capabilities";
         }

         leaf-list system-alarm-capability {
           type identityref {
             base system-alarm;
           }
           description
             "System alarm capabilities";
         }

         leaf-list time-capabilities {
           type identityref {
             base time;
           }
           description
             "The capabilities for activating the policy within a
              specific time.";
         }
       }

       container condition-capabilities {



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         description
           "Conditions capabilities.";
         container generic-nsf-capabilities {
           description
             "Conditions capabilities.
              If a network security function has the condition
              capabilities, the network security function
              supports rule execution according to conditions of
              IPv4, IPv6, TCP, UDP, SCTP, DCCP, ICMP, or ICMPv6.";
           reference
             "RFC 768: User Datagram Protocol - UDP.
              RFC 791: Internet Protocol - IPv4.
              RFC 792: Internet Control Message Protocol - ICMP.
              RFC 4443: Internet Control Message Protocol (ICMPv6)
              for the Internet Protocol Version 6 (IPv6) Specification
              - ICMPv6.
              RFC 4960: Stream Control Transmission Protocol - SCTP.
              RFC 8200: Internet Protocol, Version 6 (IPv6)
              Specification - IPv6.
              RFC 8329: Framework for Interface to Network Security
              Functions - I2NSF Flow Security Policy Structure.
              draft-ietf-tcpm-rfc793bis-25: Transmission Control
              Protocol (TCP) Specification";

           leaf-list ethernet-capability {
             type identityref {
               base ethernet;
             }
             description
               "Media Access Control (MAC) capabilities";
             reference
               "IEEE 802.3: IEEE Standard for Ethernet";
           }

           leaf-list ipv4-capability {
             type identityref {
               base ipv4;
             }
             description
               "IPv4 packet capabilities";
             reference
               "RFC 791: Internet Protocol";
           }

           leaf-list ipv6-capability {
             type identityref {
               base ipv6;
             }



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             description
               "IPv6 packet capabilities";
             reference
               "RFC 8200: Internet Protocol, Version 6 (IPv6)
                Specification - IPv6";
           }

           leaf-list icmpv4-capability {
             type identityref {
               base icmpv4;
             }
             description
               "ICMPv4 packet capabilities";
             reference
               "RFC 792: Internet Control Message Protocol - ICMP";
           }

           leaf-list icmpv6-capability {
             type identityref {
               base icmpv6;
             }
             description
               "ICMPv6 packet capabilities";
             reference
               "RFC 4443: Internet Control Message Protocol (ICMPv6)
                for the Internet Protocol Version 6 (IPv6) Specification
                - ICMPv6";
           }

           leaf-list tcp-capability {
             type identityref {
               base tcp;
             }
             description
               "TCP packet capabilities";
             reference
               "draft-ietf-tcpm-rfc793bis-25: Transmission Control
                Protocol (TCP) Specification";
           }

           leaf-list udp-capability {
             type identityref {
               base udp;
             }
             description
               "UDP packet capabilities";
             reference
               "RFC 768: User Datagram Protocol - UDP";



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           }

           leaf-list sctp-capability {
             type identityref {
               base sctp;
             }
             description
               "SCTP packet capabilities";
             reference
               "RFC 4960: Stream Control Transmission Protocol - SCTP";
           }

           leaf-list dccp-capability {
             type identityref {
               base dccp;
             }
             description
               "DCCP packet capabilities";
             reference
               "RFC 4340: Datagram Congestion Control Protocol - DCCP";
           }
         }

         container advanced-nsf-capabilities {
           description
             "Advanced Network Security Function (NSF) capabilities,
              such as Anti-DDoS, IPS, and VoIP/VoLTE.
              This container contains the leaf-lists of advanced
              NSF capabilities";

           leaf-list anti-ddos-capability {
             type identityref {
               base anti-ddos;
             }
             description
               "Anti-DDoS Attack capabilities";
           }

           leaf-list ips-capability {
             type identityref {
               base ips;
             }
             description
               "IPS capabilities";
           }

           leaf-list anti-virus-capability {
             type identityref {



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               base anti-virus;
             }
             description
               "Anti-Virus capabilities";
           }

           leaf-list url-capability {
             type identityref {
               base url-filtering;
             }
             description
               "URL capabilities";
           }

           leaf-list voip-volte-filtering-capability {
             type identityref {
               base voip-volte-filtering;
            }
             description
               "VoIP/VoLTE capabilities";
           }
         }

         container context-capabilities {
           description
             "Security context capabilities";
           leaf-list application-filter-capabilities{
             type identityref {
               base application-protocol;
             }
             description
               "Context capabilities based on the application protocol";
           }

           leaf-list target-capabilities {
             type identityref {
               base target-device;
             }
             description
               "Context capabilities based on the device attribute that
               can identify a device type
               (i.e., router, switch, pc, ios, or android).";
           }

           leaf-list user-condition-capabilities {
             type identityref {
               base user-condition;
             }



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             description
               "Context capabilities based on user condition, such as
                user-id or user-name. The users can collected into a
                user-group and identified with group-id or group-name.
                An NSF is aware of the IP address of the user provided
                by a unified user management system via network. Based
                on name-address association, an NSF is able to enforce
                the security functions over the given user (or user
                group)";
           }

           leaf-list geography-capabilities {
             type identityref {
               base geography-location;
             }
             description
               "Context condition capabilities based on the geographical
                location of the source or destination";
           }
         }
       }

       container action-capabilities {
         description
           "Action capabilities.
            If a network security function has the action capabilities,
            the network security function supports the attendant
            actions for policy rules.";

         leaf-list ingress-action-capability {
           type identityref {
             base ingress-action;
           }
           description
             "Ingress-action capabilities";
         }

         leaf-list egress-action-capability {
           type identityref {
             base egress-action;
           }
           description
             "Egress-action capabilities";
         }

         leaf-list log-action-capability {
           type identityref {
             base log-action;



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           }
           description
             "Log-action capabilities";
         }
       }

       leaf-list resolution-strategy-capabilities {
         type identityref {
           base resolution-strategy;
         }
         description
           "Resolution strategy capabilities.
            The resolution strategies can be used to specify how
            to resolve conflicts that occur between the actions
            of the same or different policy rules that are matched
            for the same packet and by particular NSF.";
       }

       leaf-list default-action-capabilities {
         type identityref {
           base default-action;
         }
         description
           "Default action capabilities.
            A default action is used to execute I2NSF policy rules
            when no rule matches a packet. The default action is
            defined as pass, drop, rate-limit, or mirror.";
       }
     }

     /*
      * Data nodes
      */

     list nsf {
       key "nsf-name";
       description
         "The list of Network Security Functions (NSFs)";
       leaf nsf-name {
         type string;
         mandatory true;
         description
           "The name of Network Security Function (NSF)";
       }
       uses nsf-capabilities;
     }
   }
   <CODE ENDS>



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               Figure 3: YANG Data Module of I2NSF Capability

7.  IANA Considerations

   This document requests IANA to register the following URI in the
   "IETF XML Registry" [RFC3688]:

   ID: yang:ietf-i2nsf-capability
   URI: urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability
   Registrant Contact: The IESG.
   XML: N/A; the requested URI is an XML namespace.
   Filename: [ TBD-at-Registration ]
   Reference: [ RFC-to-be ]


   This document requests IANA to register the following YANG module in
   the "YANG Module Names" registry [RFC7950][RFC8525]:

   Name: ietf-i2nsf-capability
   Maintained by IANA? N
   Namespace: urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability
   Prefix: nsfcap
   Module:
   Reference: [ RFC-to-be ]


8.  Privacy Considerations

   This YANG module specifies the capabilities of NSFs.  These
   capabilities are consistent with the diverse set of network security
   functions in common use in enterprise security operations.  The
   configuration of the capabilities may entail privacy sensitive
   information as explicitly outlined in Section 9.  The NSFs
   implementing these capabilities may inspect, alter or drop user
   traffic; and be capable of attributing user traffic to individual
   users.

   Due to the sensitivity of these capabilities, notice must be provided
   to and consent must be received from the users of the network.
   Additionally, the collected data and associated infrastructure must
   be secured to prevent the leakage or unauthorized disclosure of this
   private data.









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9.  Security Considerations

   The YANG module specified in this document defines a data schema
   designed to be accessed through network management protocols such as
   NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest layer of NETCONF
   protocol layers MUST use Secure Shell (SSH) [RFC4254][RFC6242] as a
   secure transport layer.  The lowest layer of RESTCONF protocol layers
   MUST use HTTP over Transport Layer Security (TLS), that is, HTTPS
   [RFC7230][RFC8446] as a secure transport layer.

   The Network Configuration Access Control Model (NACM) [RFC8341]
   provides a means of restricting access to specific NETCONF or
   RESTCONF users to a preconfigured subset of all available NETCONF or
   RESTCONF protocol operations and contents.  Thus, NACM SHOULD be used
   to restrict the NSF registration from unauthorized users.

   There are a number of data nodes defined in this YANG module that are
   writable, creatable, and deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations to these data nodes
   could have a negative effect on network and security operations.
   These data nodes are collected into a single list node.  This list
   node is defined by list nsf with the following sensitivity/
   vulnerability:

   *  list nsf: An attacker could alter the security capabilities
      associated with an NSF by disabling or enabling the functionality
      of the security capabilities of the NSF.

   Some of the readable data nodes in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control read access (e.g., via get, get-config, or
   notification) to these data nodes.  These are the subtrees and data
   nodes with their sensitivity/vulnerability:

   *  list nsf: The leak of this node to an attacker could reveal the
      specific configuration of security controls to an attacker.  An
      attacker can craft an attack path that avoids observation or
      mitigations; one may reveal topology information to inform
      additional targets or enable lateral movement; one enables the
      construction of an attack path that avoids observation or
      mitigations; one provides an indication that the operator has
      discovered the attack.

   Some of the features that this document defines capability indicators
   for are highly sensitive and/or privileged operations that inherently
   require access to individuals' private data.  These are subtrees and
   data nodes that are considered privacy sensitive:



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   *  voip-volte-filtering-capability: The NSF that is able to filter
      VoIP/VoLTE calls might identify certain individual identification.

   *  user-condition-capabilities: The capability uses a set of IP
      addresses mapped to users.

   *  geography-capabilities: The IP address used in this capability can
      identify a user's geographical location.

   It is noted that some private information is made accessible in this
   manner.  Thus, the nodes/entities given access to this data MUST be
   tightly secured, monitored, and audited to prevent leakage or other
   unauthorized disclosure of private data.  Refer to [RFC6973] for the
   description of privacy aspects that protocol designers (including
   YANG data model designers) should consider along with regular
   security and privacy analysis.

10.  References

10.1.  Normative References

   [RFC0768]  Postel, J., "User Datagram Protocol", STD 6, RFC 768,
              DOI 10.17487/RFC0768, August 1980,
              <https://www.rfc-editor.org/info/rfc768>.

   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791,
              DOI 10.17487/RFC0791, September 1981,
              <https://www.rfc-editor.org/info/rfc791>.

   [RFC0792]  Postel, J., "Internet Control Message Protocol", STD 5,
              RFC 792, DOI 10.17487/RFC0792, September 1981,
              <https://www.rfc-editor.org/info/rfc792>.

   [RFC0854]  Postel, J. and J. Reynolds, "Telnet Protocol
              Specification", STD 8, RFC 854, DOI 10.17487/RFC0854, May
              1983, <https://www.rfc-editor.org/info/rfc854>.

   [RFC0959]  Postel, J. and J. Reynolds, "File Transfer Protocol",
              STD 9, RFC 959, DOI 10.17487/RFC0959, October 1985,
              <https://www.rfc-editor.org/info/rfc959>.

   [RFC1939]  Myers, J. and M. Rose, "Post Office Protocol - Version 3",
              STD 53, RFC 1939, DOI 10.17487/RFC1939, May 1996,
              <https://www.rfc-editor.org/info/rfc1939>.







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   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC2474]  Nichols, K., Blake, S., Baker, F., and D. Black,
              "Definition of the Differentiated Services Field (DS
              Field) in the IPv4 and IPv6 Headers", RFC 2474,
              DOI 10.17487/RFC2474, December 1998,
              <https://www.rfc-editor.org/info/rfc2474>.

   [RFC3168]  Ramakrishnan, K., Floyd, S., and D. Black, "The Addition
              of Explicit Congestion Notification (ECN) to IP",
              RFC 3168, DOI 10.17487/RFC3168, September 2001,
              <https://www.rfc-editor.org/info/rfc3168>.

   [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
              A., Peterson, J., Sparks, R., Handley, M., and E.
              Schooler, "SIP: Session Initiation Protocol", RFC 3261,
              DOI 10.17487/RFC3261, June 2002,
              <https://www.rfc-editor.org/info/rfc3261>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC4250]  Lehtinen, S. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Protocol Assigned Numbers", RFC 4250,
              DOI 10.17487/RFC4250, January 2006,
              <https://www.rfc-editor.org/info/rfc4250>.

   [RFC4254]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Connection Protocol", RFC 4254, DOI 10.17487/RFC4254,
              January 2006, <https://www.rfc-editor.org/info/rfc4254>.

   [RFC4340]  Kohler, E., Handley, M., and S. Floyd, "Datagram
              Congestion Control Protocol (DCCP)", RFC 4340,
              DOI 10.17487/RFC4340, March 2006,
              <https://www.rfc-editor.org/info/rfc4340>.

   [RFC4443]  Conta, A., Deering, S., and M. Gupta, Ed., "Internet
              Control Message Protocol (ICMPv6) for the Internet
              Protocol Version 6 (IPv6) Specification", STD 89,
              RFC 4443, DOI 10.17487/RFC4443, March 2006,
              <https://www.rfc-editor.org/info/rfc4443>.






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   [RFC4766]  Wood, M. and M. Erlinger, "Intrusion Detection Message
              Exchange Requirements", RFC 4766, DOI 10.17487/RFC4766,
              March 2007, <https://www.rfc-editor.org/info/rfc4766>.

   [RFC4960]  Stewart, R., Ed., "Stream Control Transmission Protocol",
              RFC 4960, DOI 10.17487/RFC4960, September 2007,
              <https://www.rfc-editor.org/info/rfc4960>.

   [RFC5103]  Trammell, B. and E. Boschi, "Bidirectional Flow Export
              Using IP Flow Information Export (IPFIX)", RFC 5103,
              DOI 10.17487/RFC5103, January 2008,
              <https://www.rfc-editor.org/info/rfc5103>.

   [RFC5321]  Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
              DOI 10.17487/RFC5321, October 2008,
              <https://www.rfc-editor.org/info/rfc5321>.

   [RFC5595]  Fairhurst, G., "The Datagram Congestion Control Protocol
              (DCCP) Service Codes", RFC 5595, DOI 10.17487/RFC5595,
              September 2009, <https://www.rfc-editor.org/info/rfc5595>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC6335]  Cotton, M., Eggert, L., Touch, J., Westerlund, M., and S.
              Cheshire, "Internet Assigned Numbers Authority (IANA)
              Procedures for the Management of the Service Name and
              Transport Protocol Port Number Registry", BCP 165,
              RFC 6335, DOI 10.17487/RFC6335, August 2011,
              <https://www.rfc-editor.org/info/rfc6335>.

   [RFC6437]  Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme,
              "IPv6 Flow Label Specification", RFC 6437,
              DOI 10.17487/RFC6437, November 2011,
              <https://www.rfc-editor.org/info/rfc6437>.





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   [RFC6864]  Touch, J., "Updated Specification of the IPv4 ID Field",
              RFC 6864, DOI 10.17487/RFC6864, February 2013,
              <https://www.rfc-editor.org/info/rfc6864>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [RFC7230]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
              Protocol (HTTP/1.1): Message Syntax and Routing",
              RFC 7230, DOI 10.17487/RFC7230, June 2014,
              <https://www.rfc-editor.org/info/rfc7230>.

   [RFC7231]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
              Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
              DOI 10.17487/RFC7231, June 2014,
              <https://www.rfc-editor.org/info/rfc7231>.

   [RFC7323]  Borman, D., Braden, B., Jacobson, V., and R.
              Scheffenegger, Ed., "TCP Extensions for High Performance",
              RFC 7323, DOI 10.17487/RFC7323, September 2014,
              <https://www.rfc-editor.org/info/rfc7323>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.



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   [RFC8407]  Bierman, A., "Guidelines for Authors and Reviewers of
              Documents Containing YANG Data Models", BCP 216, RFC 8407,
              DOI 10.17487/RFC8407, October 2018,
              <https://www.rfc-editor.org/info/rfc8407>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

   [RFC8525]  Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K.,
              and R. Wilton, "YANG Library", RFC 8525,
              DOI 10.17487/RFC8525, March 2019,
              <https://www.rfc-editor.org/info/rfc8525>.

   [RFC8805]  Kline, E., Duleba, K., Szamonek, Z., Moser, S., and W.
              Kumari, "A Format for Self-Published IP Geolocation
              Feeds", RFC 8805, DOI 10.17487/RFC8805, August 2020,
              <https://www.rfc-editor.org/info/rfc8805>.

   [RFC9051]  Melnikov, A., Ed. and B. Leiba, Ed., "Internet Message
              Access Protocol (IMAP) - Version 4rev2", RFC 9051,
              DOI 10.17487/RFC9051, August 2021,
              <https://www.rfc-editor.org/info/rfc9051>.

   [I-D.ietf-tcpm-rfc793bis]
              Eddy, W. M., "Transmission Control Protocol (TCP)
              Specification", Work in Progress, Internet-Draft, draft-
              ietf-tcpm-rfc793bis-25, 7 September 2021,
              <https://www.ietf.org/archive/id/draft-ietf-tcpm-
              rfc793bis-25.txt>.

   [I-D.ietf-tcpm-accurate-ecn]
              Briscoe, B., K├╝hlewind, M., and R. Scheffenegger, "More
              Accurate ECN Feedback in TCP", Work in Progress, Internet-
              Draft, draft-ietf-tcpm-accurate-ecn-15, 12 July 2021,
              <https://www.ietf.org/archive/id/draft-ietf-tcpm-accurate-
              ecn-15.txt>.

   [I-D.ietf-tsvwg-udp-options]
              Touch, J., "Transport Options for UDP", Work in Progress,
              Internet-Draft, draft-ietf-tsvwg-udp-options-13, 19 June
              2021, <https://www.ietf.org/archive/id/draft-ietf-tsvwg-
              udp-options-13.txt>.

   [I-D.ietf-i2nsf-nsf-monitoring-data-model]
              Jeong, J. (., Lingga, P., Hares, S., Xia, L. (., and H.
              Birkholz, "I2NSF NSF Monitoring Interface YANG Data
              Model", Work in Progress, Internet-Draft, draft-ietf-



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              i2nsf-nsf-monitoring-data-model-11, 15 October 2021,
              <https://www.ietf.org/archive/id/draft-ietf-i2nsf-nsf-
              monitoring-data-model-11.txt>.

   [I-D.ietf-i2nsf-nsf-facing-interface-dm]
              Kim, J. (., Jeong, J. (., Park, J., Hares, S., and Q. Lin,
              "I2NSF Network Security Function-Facing Interface YANG
              Data Model", Work in Progress, Internet-Draft, draft-ietf-
              i2nsf-nsf-facing-interface-dm-15, 4 October 2021,
              <https://www.ietf.org/archive/id/draft-ietf-i2nsf-nsf-
              facing-interface-dm-15.txt>.

   [I-D.ietf-i2nsf-registration-interface-dm]
              Hyun, S., Jeong, J. P., Roh, T., Wi, S., and J. Park,
              "I2NSF Registration Interface YANG Data Model", Work in
              Progress, Internet-Draft, draft-ietf-i2nsf-registration-
              interface-dm-13, 4 October 2021,
              <https://www.ietf.org/archive/id/draft-ietf-i2nsf-
              registration-interface-dm-13.txt>.

10.2.  Informative References

   [RFC2818]  Rescorla, E., "HTTP Over TLS", RFC 2818,
              DOI 10.17487/RFC2818, May 2000,
              <https://www.rfc-editor.org/info/rfc2818>.

   [RFC6691]  Borman, D., "TCP Options and Maximum Segment Size (MSS)",
              RFC 6691, DOI 10.17487/RFC6691, July 2012,
              <https://www.rfc-editor.org/info/rfc6691>.

   [RFC6973]  Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
              Morris, J., Hansen, M., and R. Smith, "Privacy
              Considerations for Internet Protocols", RFC 6973,
              DOI 10.17487/RFC6973, July 2013,
              <https://www.rfc-editor.org/info/rfc6973>.

   [RFC8192]  Hares, S., Lopez, D., Zarny, M., Jacquenet, C., Kumar, R.,
              and J. Jeong, "Interface to Network Security Functions
              (I2NSF): Problem Statement and Use Cases", RFC 8192,
              DOI 10.17487/RFC8192, July 2017,
              <https://www.rfc-editor.org/info/rfc8192>.

   [RFC8329]  Lopez, D., Lopez, E., Dunbar, L., Strassner, J., and R.
              Kumar, "Framework for Interface to Network Security
              Functions", RFC 8329, DOI 10.17487/RFC8329, February 2018,
              <https://www.rfc-editor.org/info/rfc8329>.





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   [IANA-Protocol-Numbers]
              "Assigned Internet Protocol Numbers", Available:
              https://www.iana.org/assignments/protocol-
              numbers/protocol-numbers.xhtml, September 2020.

   [IEEE802.3-2018]
              Committee, I. S., "IEEE 802.3-2018 - IEEE Standard for
              Ethernet", August 2018,
              <https://ieeexplore.ieee.org/document/8457469>.

   [Alshaer]  Shaer, Al., Hamed, E., and H. Hamed, "Modeling and
              management of firewall policies", 2004.

   [Hirschman]
              Hirschman, L. and R. Gaizauskas, "Natural Language
              Question Answering: The View from Here", Natural Language
              Engineering 7:4, pgs 275-300, Cambridge University Press ,
              November 2001.

   [Hohpe]    Hohpe, G. and B. Woolf, "Enterprise Integration Patterns",
              ISBN 0-32-120068-3 , 2003.

   [Martin]   Martin, R.C., "Agile Software Development, Principles,
              Patterns, and Practices", Prentice-Hall , ISBN:
              0-13-597444-5 , 2002.

   [OODMP]    "https://www.oodesign.com/mediator-pattern.html".

   [OODOP]    "https://www.oodesign.com/mediator-pattern.html".

   [OODSRP]   "https://www.oodesign.com/mediator-pattern.html".

Appendix A.  Configuration Examples

   This section shows configuration examples of "ietf-i2nsf-capability"
   module for capabilities registration of general firewall.

A.1.  Example 1: Registration for the Capabilities of a General Firewall

   This section shows a configuration example for the capabilities
   registration of a general firewall in either an IPv4 network or an
   IPv6 network.









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   <nsf xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability">
    <nsf-name>general_firewall</nsf-name>
    <condition-capabilities>
     <generic-nsf-capabilities>
      <ipv4-capability>next-header</ipv4-capability>
      <ipv4-capability>flow-direction</ipv4-capability>
      <ipv4-capability>source-address</ipv4-capability>
      <ipv4-capability>destination-address</ipv4-capability>
      <tcp-capability>source-port-number</tcp-capability>
      <tcp-capability>destination-port-number</tcp-capability>
      <udp-capability>source-port-number</udp-capability>
      <udp-capability>destination-port-number</udp-capability>
     </generic-nsf-capabilities>
    </condition-capabilities>
    <action-capabilities>
     <ingress-action-capability>pass</ingress-action-capability>
     <ingress-action-capability>drop</ingress-action-capability>
     <ingress-action-capability>mirror</ingress-action-capability>
     <egress-action-capability>pass</egress-action-capability>
     <egress-action-capability>drop</egress-action-capability>
     <egress-action-capability>mirror</egress-action-capability>
    </action-capabilities>
   </nsf>

      Figure 4: Configuration XML for the Capabilities Registration of
                   a General Firewall in an IPv4 Network

   Figure 4 shows the configuration XML for the capabilities
   registration of a general firewall as an NSF in an IPv4 network.  Its
   capabilities are as follows.

   1.  The name of the NSF is general_firewall.

   2.  The NSF can inspect the IPv4 protocol header field, flow
       direction, source address(es), and destination address(es)

   3.  The NSF can inspect the port number(s) and flow direction for the
       transport layer protocol, i.e., TCP and UDP.

   4.  The NSF can control whether the packets are allowed to pass,
       drop, or mirror.










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   <nsf xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability">
    <nsf-name>general_firewall</nsf-name>
    <condition-capabilities>
     <generic-nsf-capabilities>
      <ipv6-capability>next-header</ipv6-capability>
      <ipv6-capability>flow-direction</ipv6-capability>
      <ipv6-capability>source-address</ipv6-capability>
      <ipv6-capability>destination-address</ipv6-capability>
      <tcp-capability>source-port-number</tcp-capability>
      <tcp-capability>destination-port-number</tcp-capability>
      <udp-capability>source-port-number</udp-capability>
      <udp-capability>destination-port-number</udp-capability>
     </generic-nsf-capabilities>
    </condition-capabilities>
    <action-capabilities>
     <ingress-action-capability>pass</ingress-action-capability>
     <ingress-action-capability>drop</ingress-action-capability>
     <ingress-action-capability>mirror</ingress-action-capability>
     <egress-action-capability>pass</egress-action-capability>
     <egress-action-capability>drop</egress-action-capability>
     <egress-action-capability>mirror</egress-action-capability>
    </action-capabilities>
   </nsf>

      Figure 5: Configuration XML for the Capabilities Registration of
                   a General Firewall in an IPv6 Network

   In addition, Figure 5 shows the configuration XML for the
   capabilities registration of a general firewall as an NSF in an IPv6
   network.  Its capabilities are as follows.

   1.  The name of the NSF is general_firewall.

   2.  The NSF can inspect IPv6 next header, flow direction, source
       address(es), and destination address(es)

   3.  The NSF can inspect the port number(s) and flow direction for the
       transport layer protocol, i.e., TCP and UDP.

   4.  The NSF can control whether the packets are allowed to pass,
       drop, or mirror.

A.2.  Example 2: Registration for the Capabilities of a Time-based
      Firewall

   This section shows a configuration example for the capabilities
   registration of a time-based firewall in either an IPv4 network or an
   IPv6 network.



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   <nsf xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability">
    <nsf-name>time_based_firewall</nsf-name>
    <event-capabilities>
      <time-capabilities>absolute-time</time-capabilities>
      <time-capabilities>periodic-time</time-capabilities>
    </event-capabilities>
    <condition-capabilities>
     <generic-nsf-capabilities>
      <ipv4-capability>next-header</ipv4-capability>
      <ipv4-capability>flow-direction</ipv4-capability>
      <ipv4-capability>source-address</ipv4-capability>
      <ipv4-capability>destination-address</ipv4-capability>
     </generic-nsf-capabilities>
    </condition-capabilities>
    <action-capabilities>
     <ingress-action-capability>pass</ingress-action-capability>
     <ingress-action-capability>drop</ingress-action-capability>
     <ingress-action-capability>mirror</ingress-action-capability>
     <egress-action-capability>pass</egress-action-capability>
     <egress-action-capability>drop</egress-action-capability>
     <egress-action-capability>mirror</egress-action-capability>
    </action-capabilities>
   </nsf>

      Figure 6: Configuration XML for the Capabilities Registration of
                  a Time-based Firewall in an IPv4 Network

   Figure 6 shows the configuration XML for the capabilities
   registration of a time-based firewall as an NSF in an IPv4 network.
   Its capabilities are as follows.

   1.  The name of the NSF is time_based_firewall.

   2.  The NSF can execute the security policy rule according to
       absolute time and periodic time.

   3.  The NSF can inspect the IPv4 protocol header field, flow
       direction, source address(es), and destination address(es).

   4.  The NSF can control whether the packets are allowed to pass,
       drop, or mirror.










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   <nsf xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability">
    <nsf-name>time_based_firewall</nsf-name>
    <event-capabilities>
      <time-capabilities>absolute-time</time-capabilities>
      <time-capabilities>periodic-time</time-capabilities>
    </event-capabilities>
    <condition-capabilities>
     <generic-nsf-capabilities>
      <ipv6-capability>next-header</ipv6-capability>
      <ipv6-capability>flow-direction</ipv6-capability>
      <ipv6-capability>source-address</ipv6-capability>
      <ipv6-capability>destination-address</ipv6-capability>
     </generic-nsf-capabilities>
    </condition-capabilities>
    <action-capabilities>
     <ingress-action-capability>pass</ingress-action-capability>
     <ingress-action-capability>drop</ingress-action-capability>
     <ingress-action-capability>mirror</ingress-action-capability>
     <egress-action-capability>pass</egress-action-capability>
     <egress-action-capability>drop</egress-action-capability>
     <egress-action-capability>mirror</egress-action-capability>
    </action-capabilities>
   </nsf>

      Figure 7: Configuration XML for the Capabilities Registration of
                  a Time-based Firewall in an IPv6 Network

   In addition, Figure 7 shows the configuration XML for the
   capabilities registration of a time-based firewall as an NSF in an
   IPv6 network.  Its capabilities are as follows.

   1.  The name of the NSF is time_based_firewall.

   2.  The NSF can execute the security policy rule according to
       absolute time and periodic time.

   3.  The NSF can inspect the IPv6 protocol header field, flow
       direction, source address(es), and destination address(es).

   4.  The NSF can control whether the packets are allowed to pass,
       drop, or mirror.

A.3.  Example 3: Registration for the Capabilities of a Web Filter

   This section shows a configuration example for the capabilities
   registration of a web filter.





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   <nsf xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability">
    <nsf-name>web_filter</nsf-name>
    <condition-capabilities>
     <advanced-nsf-capabilities>
      <url-capability>user-defined</url-capability>
     </advanced-nsf-capabilities>
    </condition-capabilities>
    <action-capabilities>
     <ingress-action-capability>pass</ingress-action-capability>
     <ingress-action-capability>drop</ingress-action-capability>
     <ingress-action-capability>mirror</ingress-action-capability>
     <egress-action-capability>pass</egress-action-capability>
     <egress-action-capability>drop</egress-action-capability>
     <egress-action-capability>mirror</egress-action-capability>
    </action-capabilities>
   </nsf>

      Figure 8: Configuration XML for the Capabilities Registration of
                                a Web Filter

   Figure 8 shows the configuration XML for the capabilities
   registration of a web filter as an NSF.  Its capabilities are as
   follows.

   1.  The name of the NSF is web_filter.

   2.  The NSF can inspect a URL matched from a user-defined URL.  User
       can specify their own URL.

   3.  The NSF can control whether the packets are allowed to pass,
       drop, or mirror.

A.4.  Example 4: Registration for the Capabilities of a VoIP/VoLTE
      Filter

   This section shows a configuration example for the capabilities
   registration of a VoIP/VoLTE filter.














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   <nsf xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability">
    <nsf-name>voip_volte_filter</nsf-name>
    <condition-capabilities>
     <advanced-nsf-capabilities>
      <voip-volte-filtering-capability>
       call-id
      </voip-volte-filtering-capability>
     </advanced-nsf-capabilities>
    </condition-capabilities>
    <action-capabilities>
     <ingress-action-capability>pass</ingress-action-capability>
     <ingress-action-capability>drop</ingress-action-capability>
     <ingress-action-capability>mirror</ingress-action-capability>
     <egress-action-capability>pass</egress-action-capability>
     <egress-action-capability>drop</egress-action-capability>
     <egress-action-capability>mirror</egress-action-capability>
    </action-capabilities>
   </nsf>

      Figure 9: Configuration XML for the Capabilities Registration of
                            a VoIP/VoLTE Filter

   Figure 9 shows the configuration XML for the capabilities
   registration of a VoIP/VoLTE filter as an NSF.  Its capabilities are
   as follows.

   1.  The name of the NSF is voip_volte_filter.

   2.  The NSF can inspect a voice call id for VoIP/VoLTE packets.

   3.  The NSF can control whether the packets are allowed to pass,
       drop, or mirror.

A.5.  Example 5: Registration for the Capabilities of a HTTP and HTTPS
      Flood Mitigator

   This section shows a configuration example for the capabilities
   registration of a HTTP and HTTPS flood mitigator.













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   <nsf xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-capability">
    <nsf-name>DDoS_mitigator</nsf-name>
    <condition-capabilities>
     <advanced-nsf-capabilities>
      <anti-ddos-capability>packet-rate</anti-ddos-capability>
      <anti-ddos-capability>byte-rate</anti-ddos-capability>
      <anti-ddos-capability>flow-rate</anti-ddos-capability>
     </advanced-nsf-capabilities>
    </condition-capabilities>
    <action-capabilities>
     <ingress-action-capability>pass</ingress-action-capability>
     <ingress-action-capability>drop</ingress-action-capability>
     <ingress-action-capability>mirror</ingress-action-capability>
     <egress-action-capability>pass</egress-action-capability>
     <egress-action-capability>drop</egress-action-capability>
     <egress-action-capability>mirror</egress-action-capability>
    </action-capabilities>
   </nsf>

     Figure 10: Configuration XML for the Capabilities Registration of
                      a HTTP and HTTPS Flood Mitigator

   Figure 10 shows the configuration XML for the capabilities
   registration of a HTTP and HTTPS flood mitigator as an NSF.  Its
   capabilities are as follows.

   1.  The name of the NSF is DDoS_mitigator.

   2.  The NSF can detect the amount of packet, flow, and byte rate in
       the network for potential DDoS Attack.

   3.  The NSF can control whether the packets are allowed to pass,
       drop, or mirror.

Appendix B.  Acknowledgments

   This work was supported by Institute of Information & Communications
   Technology Planning & Evaluation (IITP) grant funded by the Korea
   MSIT (Ministry of Science and ICT) (R-20160222-002755, Cloud based
   Security Intelligence Technology Development for the Customized
   Security Service Provisioning).  This work was supported in part by
   the IITP grant funded by the MSIT (2020-0-00395, Standard Development
   of Blockchain based Network Management Automation Technology).








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Appendix C.  Contributors

   This document is made by the group effort of I2NSF working group.
   Many people actively contributed to this document, such as Acee
   Lindem, Roman Danyliw, and Tom Petch.  The authors sincerely
   appreciate their contributions.

   The following are co-authors of this document:

   Patrick Lingga Department of Electrical and Computer Engineering
   Sungkyunkwan University 2066 Seo-ro Jangan-gu Suwon, Gyeonggi-do
   16419 Republic of Korea EMail: patricklink@skku.edu

   Liang Xia Huawei 101 Software Avenue Nanjing, Jiangsu 210012 China
   EMail: Frank.Xialiang@huawei.com

   Cataldo Basile Politecnico di Torino Corso Duca degli Abruzzi, 34
   Torino, 10129 Italy EMail: cataldo.basile@polito.it

   John Strassner Huawei 2330 Central Expressway Santa Clara, CA 95050
   USA EMail: John.sc.Strassner@huawei.com

   Diego R.  Lopez Telefonica I+D Zurbaran, 12 Madrid, 28010 Spain
   Email: diego.r.lopez@telefonica.com

   Hyoungshick Kim Department of Computer Science and Engineering
   Sungkyunkwan University 2066 Seo-ro Jangan-gu Suwon, Gyeonggi-do
   16419 Republic of Korea EMail: hyoung@skku.edu

   Daeyoung Hyun Department of Computer Science and Engineering
   Sungkyunkwan University 2066 Seo-ro Jangan-gu Suwon, Gyeonggi-do
   16419 Republic of Korea EMail: dyhyun@skku.edu

   Dongjin Hong Department of Electronic, Electrical and Computer
   Engineering Sungkyunkwan University 2066 Seo-ro Jangan-gu Suwon,
   Gyeonggi-do 16419 Republic of Korea EMail: dong.jin@skku.edu

   Jung-Soo Park Electronics and Telecommunications Research Institute
   218 Gajeong-Ro, Yuseong-Gu Daejeon, 34129 Republic of Korea EMail:
   pjs@etri.re.kr

   Tae-Jin Ahn Korea Telecom 70 Yuseong-Ro, Yuseong-Gu Daejeon, 305-811
   Republic of Korea EMail: taejin.ahn@kt.com

   Se-Hui Lee Korea Telecom 70 Yuseong-Ro, Yuseong-Gu Daejeon, 305-811
   Republic of Korea EMail: sehuilee@kt.com





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Authors' Addresses

   Susan Hares (editor)
   Huawei
   7453 Hickory Hill
   Saline, MI 48176
   United States of America

   Phone: +1-734-604-0332
   Email: shares@ndzh.com


   Jaehoon (Paul) Jeong (editor)
   Department of Computer Science and Engineering
   Sungkyunkwan University
   2066 Seobu-Ro, Jangan-Gu
   Suwon
   Gyeonggi-Do
   16419
   Republic of Korea

   Phone: +82 31 299 4957
   Email: pauljeong@skku.edu
   URI:   http://iotlab.skku.edu/people-jaehoon-jeong.php


   Jinyong (Tim) Kim
   Department of Electronic, Electrical and Computer Engineering
   Sungkyunkwan University
   2066 Seobu-Ro, Jangan-Gu
   Suwon
   Gyeonggi-Do
   16419
   Republic of Korea

   Phone: +82 10 8273 0930
   Email: timkim@skku.edu


   Robert Moskowitz
   HTT Consulting
   Oak Park, MI
   United States of America

   Phone: +1-248-968-9809
   Email: rgm@htt-consult.com





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   Qiushi Lin
   Huawei
   Huawei Industrial Base
   Shenzhen
   Guangdong 518129,
   China

   Email: linqiushi@huawei.com











































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