Network Working Group                                      J. Jeong, Ed.
Internet-Draft                                                 P. Lingga
Intended status: Standards Track                 Sungkyunkwan University
Expires: October 31, 2021 25 February 2022                                       S. Hares
                                                                  L. Xia
                                                                  Huawei
                                                             H. Birkholz
                                                          Fraunhofer SIT
                                                          April 29,
                                                          24 August 2021

             I2NSF NSF Monitoring Interface YANG Data Model
             draft-ietf-i2nsf-nsf-monitoring-data-model-08
             draft-ietf-i2nsf-nsf-monitoring-data-model-09

Abstract

   This document proposes an information model and the corresponding
   YANG data model of an interface for monitoring Network Security
   Functions (NSFs) in the Interface to Network Security Functions
   (I2NSF) framework.  If the monitoring of NSFs is performed with the
   NSF monitoring interface in a comprehensive way, it is possible to
   detect the indication of malicious activity, anomalous behavior, the
   potential sign of denial of service attacks, or system overload in a
   timely manner.  This monitoring functionality is based on the
   monitoring information that is generated by NSFs.  Thus, this
   document describes not only an information model for the NSF
   monitoring interface along with a YANG data diagram, but also the
   corresponding YANG data model.

Status of This Memo

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   This Internet-Draft will expire on October 31, 2021. 25 February 2022.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Use Cases for NSF Monitoring Data . . . . . . . . . . . . . .   4
   4.  Classification of NSF Monitoring Data . . . . . . . . . . . .   5
     4.1.  Retention and Emission  . . . . . . . . . . . . . . . . .   6
     4.2.  Notifications  Notifications, Events, and Events  . . . . . Records  . . . . . . . . . . .   7   8
     4.3.  Unsolicited Poll and Solicited Push . . . . . . . . . . .   7
     4.4.  I2NSF Monitoring Terminology for Retained Information . .   8
   5.  Conveyance of NSF Monitoring Information  . . . . . . . . . .   9
     5.1.  Information Types and Acquisition Methods . . . . . . . .  10
   6.  Basic Information Model for All Monitoring Data . . . . . . .  10
   7. . .   9
   6.  Extended Information Model for Monitoring Data  . . . . . . .  11
     7.1.   9
     6.1.  System Alarms . . . . . . . . . . . . . . . . . . . . . .  11
       7.1.1.  10
       6.1.1.  Memory Alarm  . . . . . . . . . . . . . . . . . . . .  11
       7.1.2.  10
       6.1.2.  CPU Alarm . . . . . . . . . . . . . . . . . . . . . .  11
       7.1.3.
       6.1.3.  Disk Alarm  . . . . . . . . . . . . . . . . . . . . .  12
       7.1.4.  11
       6.1.4.  Hardware Alarm  . . . . . . . . . . . . . . . . . . .  12
       7.1.5.  11
       6.1.5.  Interface Alarm . . . . . . . . . . . . . . . . . . .  12
     7.2.
     6.2.  System Events . . . . . . . . . . . . . . . . . . . . . .  13
       7.2.1.  12
       6.2.1.  Access Violation  . . . . . . . . . . . . . . . . . .  13
       7.2.2.  12
       6.2.2.  Configuration Change  . . . . . . . . . . . . . . . .  13
       7.2.3.  Traffic flows
       6.2.3.  Session Table Event . . . . . . . . . . . . . . . . .  13
       6.2.4.  Traffic Flows . . .  14
     7.3.  NSF Events . . . . . . . . . . . . . . . . .  14
     6.3.  NSF Events  . . . . . .  14
       7.3.1.  DDoS Detection . . . . . . . . . . . . . . . . .  14
       6.3.1.  DDoS Detection  . .  14
       7.3.2.  Session Table Event . . . . . . . . . . . . . . . . .  15
       7.3.3.  14
       6.3.2.  Virus Event . . . . . . . . . . . . . . . . . . . . .  15
       7.3.4.
       6.3.3.  Intrusion Event . . . . . . . . . . . . . . . . . . .  16
       7.3.5.  Botnet
       6.3.4.  Web Attack Event  . . . . . . . . . . . . . . . . . . . .  16
       7.3.6.  Web Attack
       6.3.5.  VoIP/VoLTE Event  . . . . . . . . . . . . . . . . . .  17
     7.4.
     6.4.  System Logs . . . . . . . . . . . . . . . . . . . . . . .  18
       7.4.1.
       6.4.1.  Access Log  . . . . . . . . . . . . . . . . . . . . .  18
       7.4.2.
       6.4.2.  Resource Utilization Log  . . . . . . . . . . . . . .  19
       7.4.3.  18
       6.4.3.  User Activity Log . . . . . . . . . . . . . . . . . .  19
     7.5.
     6.5.  NSF Logs  . . . . . . . . . . . . . . . . . . . . . . . .  20
       7.5.1.  DPI
       6.5.1.  Deep Packet Inspection Log  . . . . . . . . . . . . . . . . . . . . . . .  20
       7.5.2.  Vulnerability Scanning Log  . . . . . . . . . . . . .  21
     7.6.

     6.6.  System Counter  . . . . . . . . . . . . . . . . . . . . .  21
       7.6.1.  20
       6.6.1.  Interface Counter . . . . . . . . . . . . . . . . . .  21
     7.7.
     6.7.  NSF Counters  . . . . . . . . . . . . . . . . . . . . . .  22
       7.7.1.
       6.7.1.  Firewall Counter  . . . . . . . . . . . . . . . . . .  22
       7.7.2.
       6.7.2.  Policy Hit Counter  . . . . . . . . . . . . . . . . .  24
   8.  23
   7.  NSF Monitoring Management in I2NSF  . . . . . . . . . . . . .  24
   9.
   8.  Tree Structure  . . . . . . . . . . . . . . . . . . . . . . .  25
   10.
   9.  YANG Data Model . . . . . . . . . . . . . . . . . . . . . . .  33
   11.  32
   10. I2NSF Event Stream  . . . . . . . . . . . . . . . . . . . . .  74
   12.  76
   11. XML Examples for I2NSF NSF Monitoring . . . . . . . . . . . .  75
     12.1.  77
     11.1.  I2NSF System Detection Alarm . . . . . . . . . . . . . .  75
     12.2.  77
     11.2.  I2NSF Interface Counters . . . . . . . . . . . . . . . .  77
   13.  79
   12. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  78
   14.  80
   13. Security Considerations . . . . . . . . . . . . . . . . . . .  79
   15.  81
   14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  80
   16.  82
   15. Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  80
   17.  83
   16. References  . . . . . . . . . . . . . . . . . . . . . . . . .  81
     17.1.  83
     16.1.  Normative References . . . . . . . . . . . . . . . . . .  81
     17.2.  83
     16.2.  Informative References . . . . . . . . . . . . . . . . .  84  85
   Appendix A.  Changes from draft-ietf-i2nsf-nsf-monitoring-data-
                model-07 . . . . . . . . . . . . . . . .
           draft-ietf-i2nsf-nsf-monitoring-data-model-08 . . . . . .  86  87
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  86  87

1.  Introduction

   According to [RFC8329], the interface provided by a Network Security
   Function (NSF) (e.g., Firewall, IPS, Anti-DDoS, or Anti-Virus Anti-DDoS function) to
   administrative entities (e.g., Security Controller) to enable remote
   management (i.e., configuring and monitoring) is referred to as an
   I2NSF Monitoring Interface.  Monitoring procedures
   intent to acquire vital types  This interface enables the sharing of
   vital data with respect to NSFs, from the NSFs (e.g., alarms, records, and counters) via data in motion to the
   Security Controller through a variety of mechanisms (e.g., queries,
   notifications, and events).  The monitoring of NSF plays an important
   role in an overall security framework, if it is done in a timely and
   comprehensive way.  The monitoring information generated by an NSF
   can be a good, early indication of anomalous behavior or malicious
   activity, such as denial of service attacks (DoS).

   This document defines a comprehensive information model of an NSF
   monitoring interface that provides visibility for into an NSF for an the NSF
   data collector (e.g., Security Controller and NSF Data Analyzer). Controller).  Note that an NSF data
   collector is defined as an entity to collect NSF monitoring data from
   an NSF, such as Security Controller and NSF
   Data Analyzer. Controller.  It specifies the information
   and illustrates the methods that enable an NSF to provide the
   information required in order to be monitored in a scalable and
   efficient way via the NSF Monitoring Interface.  The information
   model for the NSF monitoring interface presented in this document is a
   complementary information
   model to the information model for the security policy provisioning functionality of
   the NSF-Facing Interface specified in
   [I-D.ietf-i2nsf-nsf-facing-interface-dm].

   This document also defines a YANG [RFC7950] data model for the NSF
   monitoring interface, which is derived from the information model for
   the NSF monitoring interface.

2.  Terminology

   This

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document uses the terminology are to be interpreted as described in [RFC8329].

   This document follows the guidelines of 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) [RFC8342].  The meaning of the symbols
   in tree diagrams is defined in [RFC8340].

3.  Use Cases for NSF Monitoring Data

   As mentioned earlier, monitoring plays a critical role in an overall
   security framework.  The monitoring of the NSF provides very valuable
   information to an NSF data collector (e.g., Security Controller and
   NSF data analyzer) Controller) in
   maintaining the provisioned security posture.  Besides this, there
   are various other reasons to monitor the NSF as listed below:

   o

   *  The security administrator with I2NSF User can configure a policy
      that is triggered on a specific event occurring in the NSF or the
      network [RFC8329] [I-D.ietf-i2nsf-consumer-facing-interface-dm].
      If an NSF data collector detects the specified event, it
      configures additional security functions as defined by policies.

   o

   *  The events triggered by an NSF as a result of security policy
      violation can be used by Security Information and Event Management
      (SIEM) to detect any suspicious activity in a larger correlation
      context.

   o

   *  The events information (i.e., events, records, and activity logs counters) from an NSF
      can be used to build advanced analytics, such as behavior and
      predictive models to improve security posture in large
      deployments.

   o

   *  The NSF data collector can use events from the NSF for achieving
      high availability.  It can take corrective actions such as
      restarting a failed NSF and horizontally scaling up the NSF.

   o

   *  The events information (i.e., events, records, and activity logs counters) from the NSF
      can aid in the root cause analysis of an operational issue, so it
      can improve debugging.

   o

   *  The activity logs records from the NSF can be used to build historical data for operational
      operation and business reasons.

4.  Classification of NSF Monitoring Data

   In order to maintain a strong security posture, it is not only
   necessary not only to configure an NSF's security policies but also to
   continuously monitor the NSF by consuming acquirable and observable information.
   data.  This enables security administrators to assess the state of
   the network topology networks and in a timely fashion.  It is not possible to block
   all the internal and external threats based on static security
   posture.  A more practical approach is supported by enabling dynamic
   security measures, for which continuous visibility is required.  This
   document defines a set of information monitoring elements
   (and and their scope) scopes that
   can be acquired from an NSF and can be used as NSF monitoring information. data.
   In essence, these types of monitoring
   information data can be leveraged to
   support constant visibility on multiple levels of granularity and can
   be consumed by the corresponding functions.

   Three basic domains about the monitoring information data originating from a
   system entity [RFC4949] or [RFC4949], i.e., an NSF NSF, are highlighted in this
   document.

   o

   *  Retention and Emission

   o  Notifications

   *  Notifications, Events, and Events

   o Records

   *  Unsolicited Poll and Solicited Push

   The Alarm Management Framework in [RFC3877] defines an Event as
   something that happens as a thing of of interest.  It defines a fault
   as a change in status, crossing a threshold, or an external input to
   the system.  In the I2NSF domain, I2NSF events are created and the
   scope of the Alarm Management Framework's Events is still applicable
   due to its broad definition.  The model presented in this document
   elaborates on the workflow of creating I2NSF events in the context of
   NSF monitoring and on the way initial I2NSF events are created.
   As with I2NSF components, every generic system entity can include a
   set of capabilities that creates information about the context, some context with
   monitoring data (i.e., monitoring information), composition,
   configuration, state or behavior of that system entity.  This
   information is intended to be provided to other consumers of
   information and in the scope of this document, which deals with NSF
   information
   monitoring data in an automated fashion.

4.1.  Retention and Emission

   Typically, a

   A system entity populates standardized interface, such as
   SNMP, NETCONF, RESTCONF or CoMI to provide and emit created (e.g., NSF) first retains I2NSF monitoring data
   inside its own system before emitting the information directly via another I2NSF
   component (e.g., NSF Monitoring Interface.  Alternatively,
   the created Data Collector).  The I2NSF monitoring
   information consist of I2NSF Event, I2NSF Record, and I2NSF Counter
   as follows:

   I2NSF Event:  I2NSF Event is retained inside defined as an important occurrence over
      time, that is, a change in the system entity (or being managed or a
   hierarchy change in
      the environment of the system entities in a composite device) via records or
   counters that are not exposed directly via NSF Monistoring Interface.

   Information emitted via standardized interfaces can being managed.  An I2NSF Event
      requires immediate attention and should be consumed by notified as soon as
      possible.  When used in the context of an (imperative) I2NSF User that includes the capability to consume information not
   only via
      Policy Rule, an I2NSF Interface (e.g., Consumer-Facing Interface
   [I-D.ietf-i2nsf-consumer-facing-interface-dm]), but also via
   interfaces complementary Event is used to determine whether the standardized interfaces a generic
   system entity provides.

   Information retained on a system entity requires a corresponding
   I2NSF User to access aggregated records
      Condition clause of information, typically that Policy Rule can be evaluated or not.  The
      Alarm Management Framework in
   the form [RFC3877] defines an event as
      something that happens which may be of log-files or databases.  There interest.  Examples for an
      event are ways to aggregate
   records originating from different system entities over a network,
   for examples via Syslog Protocol [RFC5424] fault, a change in status, crossing a threshold, or Syslog over TCP
   [RFC6587].  But even if records are conveyed, an
      external input to the result is system.  In the same
   kind of retention in form of a bigger aggregate of records on another
   system entity.

   An I2NSF User is required to process fresh [RFC4949] records created
   by domain, I2NSF Functions events
      are created following the definition of an event in order to provide them to other I2NSF Components
   via the corresponding Alarm
      Management Framework.

   I2NSF Interfaces in a timely manner.  This
   process Record:  A record is effectively based on homogenizing functions, which can
   access and convert specific kinds defined as an item of records into information that
   can be provided and emitted via I2NSF interfaces.

   When retained or emitted, the information required to support
   monitoring processes has is
      kept to be processed by an I2NSF User looked at some
   point and used in the workflow.  Typical locations of these future.  Unlike I2NSF Users are:

   o  a system entity that creates the information

   o  a system entity that retains an aggregation of records

   o  an I2NSF Component that includes the capabilities of using
      standardized interfaces provided by other system entities that are
      not I2NSF Components

   o  an I2NSF Component that creates the information

4.2.  Notifications and Events

   A specific task of I2NSF User is to process I2NSF Policy Rules.  The
   rules of a policy are composed of three clauses: Events, Conditions,
   and Actions.  In consequence, an I2NSF Event is specified to trigger
   an I2NSF Policy Rule.  Such an I2NSF Event is defined as any
   important occurrence over time in the system being managed, and/or in
   the environment of the system being managed, which aligns well with
   the generic definition of Event from [RFC3877].

   The model illustrated in this document introduces a complementary
   type of information that can be a conveyed notification.

   Notification:  An occurrence of a change of context, composition,
      configuration, state or behavior of a system entity that can be
      directly or indirectly observed by an I2NSF User and can be used
      as input for an event-clause in I2NSF Policy Rules.

      A notification is similar to an I2NSF Event with the exception
      that it is created by a system entity that is not an I2NSF
      Component and that its importance is yet to be assessed.
      Semantically, a notification is not an I2NSF Event in the context
      of I2NSF, although they can potentially use the exact same
      information or data model.  In respect to [RFC3877], a
      Notification is a specific subset of events, because they convey
      information about something that happens as a thing of of
      interest.  In consequence, Notifications may contain information
      with very low expressiveness or relevance.  Hence, additional
      post-processing functions, such as aggregation, correlation or
      simple anomaly detection, might have to be employed to satisfy a
      level of expressiveness that is required for an event-clause of an
      I2NSF Policy Rule.

   It is important to note that the consumer of a notification (the
   observer) assesses the importance of a notification and not the
   producer.  The producer can include metadata in a notification that
   supports the observer in assessing the importance (even metadata
   about severity), but the deciding entity is an I2NSF User.

4.3.  Unsolicited Poll and Solicited Push

   The freshness of the monitored information depends on the acquisition
   method.  Ideally, an I2NSF User is accessing every relevant
   information about the I2NSF Component and is emitting I2NSF Events to
   an NSF data collector (e.g., Security Controller and NSF data
   analyzer) in a timely manner.  Publication of events via a pubsub/
   broker model, peer-2-peer meshes, or static defined channels are only
   a few examples on how a solicited push of I2NSF Events can be
   facilitated.  The actual mechanic implemented by an I2NSF Component
   is out of the scope of this document.

   Often, the corresponding management interfaces have to be queried in
   intervals or on-demand if required by an I2NSF Policy rule.  In some
   cases, a collection of information has to be conducted via login
   mechanics provided by a system entity.  Accessing records of
   information via this kind of unsolicited polls can introduce a
   significant latency in regard to the freshness of the monitored
   information.  The actual definition of intervals implemented by an
   I2NSF Component is also out of scope of this document.

4.4.  I2NSF Monitoring Terminology for Retained Information

   Records:  Unlike information emitted via notifications and events, Event,
      records do not require immediate attention from an analyst but may be useful for
      visibility and retroactive cyber forensic.  Depending on the
      record format, there are different qualities in regard to
      structure and detail.  Records are typically stored in log-files
      or databases on a system entity or NSF.  Records in the form of
      log-files usually include less structures but potentially more
      detailed information in regard to the changes of a system entity's
      characteristics.  In contrast, databases often use more strict
      schemas or data models, therefore enforcing a better structure.
      However, they inhibit storing information that do does not match
      those models ("closed world assumption").  Records can be
      continuously processed by I2NSF Agents that act a system entity as an I2NSF Producer and emit events via functions specifically
      emitted with a format tailored to a certain type of record.
      Typically, records are information generated
      either by an NSF or a system entity about
      (e.g., NSF) that is based on operational and informational data, or
      that is, various changes in system characteristics,
      such characteristics.  The examples
      of records include as user activities, network/traffic status, and
      network activity.  They are important for debugging, auditing and
      security
      forensic.

   Counters:  A forensic of a system entity or the network having the
      system entity.

   I2NSF Counter:  An I2NSF Counter is defined as a specific
      representation of continuous value changes of information elements
      that potentially occur in high frequency.  Prominent example examples are
      network interface counters, e.g., PDU amount
      or counters for protocol data unit (PDU) amount,
      byte amount, drop counters, and error counters.  Counters are
      useful in debugging and visibility into operational behavior of a
      system entity (e.g., NSF).  When an
      NSF.  An NSF data collector asks for
      the value of a counter to it, a system entity emits

   For the utilization of the storage space for accumulated NSF
   monitoring data, all of the information MUST provide the general
   information (e.g., timestamp) for purging existing records, which is
   discussed in Section 5.  This document provides a YANG data model in
   Section 9 for the important I2NSF Agent monitoring information that observes should
   be retained.  All of the information in the data model is considered
   important and should be kept permanently as the information might be
   useful in many circumstances in the future.  The allowed cases for
   removing some monitoring information include the following:

   *  When the system storage is full to create a fresh record
      [RFC4949], the oldest record can be removed.

   *  The administrator deletes existing records manually after
      analyzing the information in them.

   The I2NSF monitoring information retained on a system entity (e.g.,
   NSF) may be delivered to a corresponding I2NSF User via an NSF data
   collector.  The information consists of the aggregated records,
   typically in the form of log-files or databases.  For the NSF
   Monitoring Interface to deliver the information to the NSF data
   collector, the NSF needs to accommodate standardized delivery
   protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040].  The NSF
   data collector can forward the information to the I2NSF User through
   one of standardized delivery protocols.  The interface for this
   delivery is out of the progression scope of this document.

4.2.  Notifications, Events, and Records

   A specific task of counters can
      act as an I2NSF Producer and emit events in respect User is to process I2NSF Policy Rules.

5.  Conveyance  The
   rules of NSF Monitoring Information

   As per the use cases a policy are composed of NSF monitoring data, information needs to be
   conveyed three clauses: Event, Condition,
   and Action clauses.  In consequence, an I2NSF Event is specified to various
   trigger an I2NSF Consumers based on requirements imposed by Policy Rule.  Such an I2NSF Capabilities and workflows.  There are multiple aspects to be
   considered Event is defined as any
   important occurrence over time in the system being managed, and/or in regard to
   the emission environment of monitoring information to
   requesting parties as listed below:

   o  Pull-Push Model: A set the system being managed, which aligns well with
   the generic definition of data can be pushed by an NSF to a
      requesting party or pulled by a requesting party Event from an NSF.
      Specific types [RFC3877].

   Another role of information might need both the models at the
      same time if there are multiple I2NSF Consumers with varying
      requirements.  In general, any I2NSF Event including a high
      severity assessment is considered to be trigger a notification for
   monitoring the status of great importance and
      should be processed an NSF.  A notification is defined in
   [RFC3877] as soon an unsolicited transmission of management information.
   System alarm (called alarm) is defined as possible (push-model).  Records, a warning related to
   service degradation in
      contrast, are typically not system hardware in Section 6.1.  System event
   (called alert) is defined as critical (pull-model).  The I2NSF
      Architecture does not mandate a specific scheme for each type warning about any changes of
   configuration, any access violation, the information and is therefore out of scope of this document.

   o  Pub-Sub Model: In order for sessions and
   traffic flows in Section 6.2.  Both an alarm and an alert are I2NSF Provider to push monitoring
      information to multiple appropriate I2NSF Consumers,
   Events that can be delivered as a notification.  The model
   illustrated in this document introduces a
      subscription can be maintained by both I2NSF Components.
      Discovery complementary type of available monitoring
   information that can be supported by
      an a conveyed notification.

   In I2NSF Controller that takes the role of monitoring, a broker notification is used to deliver either an
   event and therefore
      includes a record via the I2NSF Capabilities that support registration.

   o  Export Frequency: Monitoring information can be emitted
      immediately upon generation by an NSF to requesting I2NSF
      Consumers or can be pushed periodically. Interface.  The frequency of
      exporting
   difference between the data depends upon its size event and timely usefulness.
      It record is out of the scope of I2NSF and left timing by which the
   notifications are emitted.  An event is emitted as soon as it happens
   in order to each NSF
      implementation.

   o  Authentication: There may be a need for authentication between notify an
      I2NSF Producer NSF Data Collector of monitoring information and its corresponding
      I2NSF Consumer to ensure the problem that critical information remains
      confidential.  Authentication in needs
   immediate attention.  A record is not emitted immediately to the scope of I2NSF can also
      require its corresponding content authorization.  This may be
      necessary, for example, if an NSF emits monitoring information to
      an I2NSF Consumer outside its administrative domain.  The I2NSF
      Architecture does not mandate when
   Data Collector, and how specific authentication
      has to be implemented.

   o  Data-Transfer Model: Monitoring information it can be pushed by an emitted periodically to the NSF using a connection-less model Data
   Collector every certain time interval.

   It is important to note that does require an NSF Data Collector as a persistent
      connection or streamed over consumer
   (i.e., observer) of a persistent connection.  An
      appropriate model depends on the I2NSF Consumer requirements and notification assesses the semantics importance of the information to be conveyed.

   o  Data Model and Interaction Model for Data
   notification rather than an NSF as a producer.  The producer can
   include metadata in Motion: There are a
      lot of transport mechanisms such as IP, UDP, and TCP.  There are
      also open source implementations for specific set of data such as
      systems counter, e.g.  IPFIX [RFC7011] notification that supports the observer in
   assessing its importance (e.g., severity).

4.3.  Unsolicited Poll and NetFlow [RFC3954]. Solicited Push

   The freshness of the monitored information depends on the acquisition
   method.  Ideally, an I2NSF does not mandate any specific method for a given data set,
      so it User is up to each implementation.

5.1.  Information Types and Acquisition Methods

   In this document, most defined accessing every relevant
   information types defined benefit from
   high visibility with respect to value changes, e.g., alarms and
   records.  In contrast, values that change monotonically in a
   continuous way do not benefit from this high visibility.  On about the
   contrary, I2NSF Component and is emitting each change would result I2NSF Events to
   an NSF data collector (e.g., Security Controller) in a useless amount timely manner.
   Publication of
   value updates.  Hence, values, such as counter, events via a pubsub/broker model, peer-2-peer meshes,
   or static defined channels are best acquired in
   periodic intervals. only a few examples on how a solicited
   push of I2NSF Events can be facilitated.  The mechanisms provided actual mechanism
   implemented by YANG Push [I-D.ietf-netconf-yang-push] and
   YANG Subscribed Notifications
   [I-D.ietf-netconf-subscribed-notifications] address exactly these set an I2NSF Component is out of requirements.  YANG also enables semantically well-structured
   information, as well as subscriptions the scope of this
   document.

   Often, the corresponding management interfaces have to datastores be queried in
   intervals or event streams
   - on demand if required by changes or periodically. an I2NSF Policy rule.  In consequence, this some
   cases, the collection of information model in this document is intended has to support data models used in solicited or unsolicited event streams
   that potentially are facilitated be conducted via a login
   mechanism provided by a subscription mechanism.  A
   subset system entity.  Accessing records of
   information elements defined via this kind of unsolicited polls can introduce a
   significant latency in regard to the information model
   address this domain freshness of application.

6. the monitored
   information.  The actual definition of intervals implemented by an
   I2NSF Component is also out of scope of this document.

5.  Basic Information Model for All Monitoring Data

   As explained in the above section, there is a wealth of data
   available from the NSF that can be monitored.  Firstly, there must be
   some general information with each monitoring message sent from an
   NSF that helps a consumer to identify meta data with that message,
   which are listed as below:

   o

   *  message: Event, Alert, Alarm, Log, Counter, etc.

   o The extra detail to give the context of the information.

   *  vendor-name: The name of the NSF vendor.

   o

   *  nsf-name: The name (or IP) or IP address of the NSF generating the
      message.

   o  If the given nsf-name is not an IP address, the name can
      be an arbitrary string including FQDN (Fully Qualified Domain
      Name).  The name MUST be unique for different NSFs to identify the
      NSF that generates the message.

   *  severity: It indicates the severity level.  There are total four
      levels, from 0 i.e., critical, high, middle, and low.

   *  timestamp: Indicates the time when the message is generated.  For
      the notification operations (i.e., System Alarms, System Events,
      NSF Events, System Logs, and NSF Logs), this is represented by the
      eventTime of NETCONF event notification [RFC5277] For other
      operations (i.e., System Counter and NSF Counter), the timestamp
      MUST be provided separately.

6.  Extended Information Model for Monitoring Data

   This section covers the additional information associated with the
   system messages.  The extended information model is only for the
   structured data such as events, record, and counters.  Any
   unstructured data is specified with the basic information model only.

   Each information has characteristics as follows:

   *  Acquisition method: The method to 3. obtain the message.  It can be a
      "query" or a "subscription".  A "query" is a request-based method
      to acquire the solicited information.  A "subscription" is a
      subscribe-based method to acquire the unsolicited information.

   *  Emission type: The smaller cause type for the numeral is, message to be emitted.  It
      can be "on-change" or "periodic".  An "on-change" message is
      emitted when an important event happens in the NSF.  A "periodic"
      message is emitted at a certain time interval.  The time to
      periodically emit the message is configurable.

   *  Dampening type: The type of message dampening to stop the rapid
      transmission of messages.  The dampening types are "on-repetition"
      and "no-dampening".  The "on-repetition" type limits the higher
      transmitted "on-change" message to one message at a certain
      interval.  This interval is defined as dampening-period in
      [RFC8641].  The dampening-period is configurable.  The "no-
      dampening" type does not limit the
      severity is.

7.  Extended Information Model transmission for Monitoring Data

   This section covers the additional information associated with messages
      of the
   system messages.  The extended information model same type.  In short, "on-repetition" means that the
      dampening is only active and "no-dampening" is inactive.  It is
      recommended to activate the dampening for an "on-change" type of
      message to reduce the
   structured data such as alarm.  Any unstructured data is specified
   with basic information model only.

7.1. number of messages generated.

6.1.  System Alarms

   Characteristics:

   o

   System alarms have the following characteristics:

   *  acquisition-method: subscription

   o

   *  emission-type: on-change

   o

   *  dampening-type: on-repetition

7.1.1.

6.1.1.  Memory Alarm

   The memory is the hardware to store information temporarily or for a
   short period, i.e., Random Access Memory (RAM).  The memory-alarm is
   emitted when the RAM usage exceeds the threshold.  The following
   information should be included in a Memory Alarm:

   o

   *  event-name: mem-usage-alarm

   o memory-alarm.

   *  usage: specifies the size of memory used.

   o

   *  threshold: The threshold triggering the alarm

   o

   *  severity: The severity of the alarm such as critical, high,
      medium, low

   o and low.

   *  message: The Simple information such as "The memory usage exceeded the threshold

7.1.2.
      threshold" or with extra information.

6.1.2.  CPU Alarm

   CPU is the Central Processing Unit that executes basic operations of
   the system.  The cpu-alarm is emitted when the CPU usage exceeds the
   threshold.  The following information should be included in a CPU
   Alarm:

   o

   *  event-name: cpu-usage-alarm

   o cpu-alarm.

   *  usage: Specifies the size of CPU used.

   o

   *  threshold: The threshold triggering the event

   o event.

   *  severity: The severity of the alarm such as critical, high,
      medium, low

   o and low.

   *  message: The Simple information such as "The CPU usage exceeded the threshold.

7.1.3.
      threshold" or with extra information.

6.1.3.  Disk Alarm

   Disk is the hardware to store information for a long period, i.e.,
   Hard Disk or Solid-State Drive.  The disk-alarm is emitted when the
   Disk usage exceeds the threshold.  The following information should
   be included in a Disk Alarm:

   o

   *  event-name: disk-usage-alarm

   o disk-alarm.

   *  usage: Specifies the size of disk space used.

   o

   *  threshold: The threshold triggering the event

   o event.

   *  severity: The severity of the alarm such as critical, high,
      medium, low

   o and low.

   *  message: The Simple information such as "The disk usage exceeded the threshold.

7.1.4.
      threshold" or with extra information.

6.1.4.  Hardware Alarm

   The hardware-alarm is emitted when a hardware, e.g., CPU, memory,
   disk, or interface, problem is detected.  The following information
   should be included in a Hardware Alarm:

   o

   *  event-name: hw-failure-alarm

   o hardware-alarm.

   *  component-name: It indicates the HW hardware component responsible
      for generating this alarm.

   o

   *  severity: The severity of the alarm such as critical, high,
      medium, low

   o and low.

   *  message: The HW Simple information such as "The hardware component has
      failed or degraded.

7.1.5. degraded" or with extra information.

6.1.5.  Interface Alarm

   Interface is the network interface for connecting a device with the
   network.  The interface-alarm is emitted when the state of the
   interface is changed.  The following information should be included
   in an Interface Alarm:

   o

   *  event-name: ifnet-state-alarm

   o interface-alarm.

   *  interface-name: The name of interface

   o the interface.

   *  interface-state: up, down, up (not congested), congested

   o  threshold: The threshold triggering the event

   o (up but
      congested).

   *  severity: The severity of the alarm such as critical, high,
      medium, low

   o and low.

   *  message: Current Simple information such as "The interface state

7.2. is 'interface-
      state'" or with extra information.

6.2.  System Events

   Characteristics:

   o

   System events (as alerts) have the following characteristics:

   *  acquisition-method: subscription

   o

   *  emission-type: on-change

   o

   *  dampening-type: on-repetition

7.2.1.

6.2.1.  Access Violation

   The access-violation system event is an event when a user tries to
   access (read or write) any information above their privilege.  The
   following information should be included in this event:

   o

   *  event-name: access-denied

   o access-denied.

   *  user: Name of a user

   o user.

   *  group: Group Group(s) to which a user belongs

   o  login-ip-address: Login belongs.  A user can belong to
      multiple groups.

   *  ip-address: The IP address of a the user

   o that triggered the event.

   *  authentication: User authentication mode. e.g., Local
      Authentication, Third-Party Server Authentication, Authentication
      Exemption, Single Sign-On (SSO) Authentication

   o The method to verify the valid user, i.e., pre-
      configured-key and certificate-authority.

   *  message: access The message to give the context of the event, such as
      "Access is denied.

7.2.2. denied".

6.2.2.  Configuration Change

   A configuration change is a system event when a new configuration is
   added or an existing configuration is modified.  The following
   information should be included in this event:

   o

   *  event-name: config-change

   o config-change.

   *  user: Name of a user

   o user.

   *  group: Group Group(s) to which a user belongs

   o  login-ip-address: Login belongs.  A user can belong to
      multiple groups.

   *  ip-address: The IP address of a the user

   o that triggered the event.

   *  authentication: User authentication mode. e.g., Local
      Authentication, Third-Party Server Authentication, Authentication
      Exemption, SSO Authentication

   o The method to verify the valid user, i.e., pre-
      configured-key and certificate-authority.

   *  message: Configuration The message to give the context of the event, such as
      "Configuration is modified.

7.2.3. modified" or "New configuration is added".

6.2.3.  Session Table Event

   The following information should be included in a Session
   Table Event:

   *  event-name: session-table.

   *  current-session: The number of concurrent sessions.

   *  maximum-session: The maximum number of sessions that the session
      table can support.

   *  threshold: The threshold triggering the event.

   *  message: The message to give the context of the event, such as
      "The number of session table exceeded the threshold".

6.2.4.  Traffic Flows

   Traffic flows need to be monitored because they might be used for
   security attacks to the network.  The following information should be
   included in this event:

   o

   *  src-ip: The source IPv4 or IPv6 address of the flows

   o traffic flow.

   *  dst-ip: The destination IPv4 or IPv6 address of the flows

   o traffic flow.

   *  src-port: The source port of the flows

   o traffic flow.

   *  dst-port: The destination port of the flows

   o traffic flow.

   *  protocol: The protocol of the packet flows.

   o traffic flow.

   *  arrival-rate: Arrival rate of packets of the same traffic flow.

7.3.

6.3.  NSF Events

   Characteristics:

   o

   NSF events have the following characteristics:

   *  acquisition-method: subscription

   o

   *  emission-type: on-change

   o

   *  dampening-type: on-repetition

7.3.1.

6.3.1.  DDoS Detection

   The following information should be included in a DDoS Event:

   o

   *  event-name: detection-ddos

   o detection-ddos.

   *  attack-type: Any one of SYN flood, ACK flood, SYN-ACK flood, FIN/
      RST flood, TCP Connection flood, UDP flood, ICMP flood, HTTPS
      flood, HTTP flood, DNS query flood, DNS reply flood, SIP flood,
      SSL flood, and etc.

   o  dst-ip: NTP amplification flood.

   *  attack-src-ip: The IP address of the source of the DDoS attack.

   *  attack-dst-ip: The network prefix with a network mask (for IPv4)
      or prefix length (for IPv6) of a victim under attack

   o DDoS attack.

   *  dst-port: The port number that the attack traffic aims at.

   o

   *  start-time: The time stamp indicating when the attack started

   o started.

   *  end-time: The time stamp indicating when the attack ended.  If the
      attack is still undergoing when sending out the alarm, this field
      can be empty.

   o

   *  attack-rate: The PPS packets per second of attack traffic
   o traffic.

   *  attack-speed: the bps bits per second of attack traffic

   o traffic.

   *  rule-name: The name of the rule I2NSF Policy Rule being triggered

   o  profile: Security profile triggered.
      Note that traffic matches.

7.3.2.  Session Table Event

   The following information should be included in rule-name is used to match a Session
   Table Event:

   o  event-name: session-table

   o  current-session: The number of concurrent sessions

   o  maximum-session: The maximum number of sessions that the session
      table can support

   o  threshold: The threshold triggering the detected NSF event

   o  message: The number of session table exceeded the threshold.

7.3.3. with a
      policy rule in [I-D.ietf-i2nsf-nsf-facing-interface-dm], and also
      that there is no rule-name in a system event.

6.3.2.  Virus Event

   The following information should be included in a Virus Event:

   o

   *  event-name: detection-virus

   o detection-virus.

   *  virus: Type of the virus. e.g., trojan, worm, macro virus type

   o type.

   *  virus-name: Name of the virus

   o virus.

   *  dst-ip: The destination IP address of the packet where the virus
      is found

   o found.

   *  src-ip: The source IP address of the packet where the virus is
      found

   o
      found.

   *  src-port: The source port of the packet where the virus is found

   o found.

   *  dst-port: The destination port of the packet where the virus is
      found

   o
      found.

   *  src-zone: The source security zone geographical location (e.g., country and
      city) of the packet where the virus
      is found

   o virus.

   *  dst-zone: The destination security zone geographical location (e.g., country and
      city) of the packet where the
      virus is found

   o virus.

   *  file-type: The type of the file where the virus is hided within

   o within.

   *  file-name: The name of the file where the virus is hided within

   o  raw_info: within.

   *  raw-info: The information describing the packet triggering the
      event.

   o  rule_name:

   *  rule-name: The name of the rule being triggered

7.3.4. triggered.

6.3.3.  Intrusion Event

   The following information should be included in an Intrusion Event:

   o

   *  event-name: The name of the event. e.g., detection-intrusion

   o detection-intrusion.

   *  attack-type: Attack type, e.g., brutal force and buffer overflow

   o overflow.

   *  src-ip: The source IP address of the packet

   o flow.

   *  dst-ip: The destination IP address of the packet

   o flow.

   *  src-port:The source port number of the packet

   o flow.

   *  dst-port: The destination port number of the packet

   o flow

   *  src-zone: The source security zone of the packet

   o  dst-zone: The destination security zone of the packet

   o  protocol: The employed transport layer protocol. e.g.,TCP and UDP

   o  app: The employed application layer protocol. e.g.,HTTP geographical location (e.g., country and FTP

   o  rule-name: The name of the rule being triggered

   o  raw-info: The information describing the packet triggering the
      event

7.3.5.  Botnet Event

   The following information should be included in a Botnet Event:

   o  event-name: The name of event. e.g., detection-botnet

   o  botnet-name: The name of the detected botnet

   o  src-ip: The source IP address of the packet
   o  dst-ip: The destination IP address of the packet

   o  src-port: The source port number of the packet

   o  dst-port: The destination port number of the packet

   o  src-zone: The source security zone
      city) of the packet

   o flow.

   *  dst-zone: The destination security zone geographical location (e.g., country and
      city) of the packet

   o flow.

   *  protocol: The employed transport layer protocol. e.g.,TCP e.g., TCP and UDP

   o  role: The role of the communicating parties within the botnet:

      1.  The packet from the zombie host to the attacker

      2.  The packet from the attacker to the zombie host

      3.  The packet from the IRC/WEB server to the zombie host

      4.  The packet from the zombie host to the IRC/WEB server

      5.  The packet from the attacker to the IRC/WEB server

      6.  The packet from the IRC/WEB server to the attacker

      7.
      UDP.

   *  app: The packet from the zombie host to the victim

   o employed application layer protocol. e.g., HTTP and FTP.

   *  rule-name: The name of the rule I2NSF Policy Rule being triggered

   o triggered.

   *  raw-info: The information describing the packet flow triggering the
      event.

7.3.6.

6.3.4.  Web Attack Event

   The following information should be included in a Web Attack Alarm:

   o

   *  event-name: The name of event. e.g., detection-web-attack

   o detection-web-attack.

   *  attack-type: Concrete web attack type. e.g., SQL injection,
      command injection, XSS, CSRF

   o CSRF.

   *  src-ip: The source IP address of the packet

   o packet.

   *  dst-ip: The destination IP address of the packet

   o packet.

   *  src-port: The source port number of the packet
   o packet.

   *  dst-port: The destination port number of the packet

   o packet.

   *  src-zone: The source security zone geographical location (e.g., country and
      city) of the packet

   o packet.

   *  dst-zone: The destination security zone geographical location (e.g., country and
      city) of the packet

   o packet.

   *  request-method: The method of requirement.  For instance, "PUT"
      and "GET" in HTTP

   o HTTP.

   *  req-uri: Requested URI

   o  rsp-code: URI.

   *  response-code: The HTTP Response code

   o  req-clientapp: code.

   *  req-user-agent: The client application

   o HTTP request user agent header field.

   *  req-cookies: Cookies

   o The HTTP Cookie previously sent by the server with
      Set-Cookie.

   *  req-host: The domain name of the requested host

   o host.

   *  uri-category: Matched URI category

   o category.

   *  filtering-type: URL filtering type. e.g., Blacklist, Whitelist,
      User-Defined, Predefined, Malicious Category, deny-list, allow-list,
      and Unknown

   o unknown.

   *  rule-name: The name of the rule I2NSF Policy Rule being triggered

   o  profile: Security profile triggered.

6.3.5.  VoIP/VoLTE Event

   The following information should be included in a VoIP/VoLTE Event:

   *  source-voice-id: The detected source voice Call ID for VoIP and
      VoLTE that traffic matches

7.4. violates the policy.

   *  destination-voice-id: The destination voice Call ID for VoIP and
      VoLTE that violates the policy.

   *  user-agent: The user agent for VoIP and VoLTE that violates the
      policy.

   *  src-ip: The source IP address of the VoIP/VoLTE.

   *  dst-ip: The destination IP address of the VoIP/VoLTE.

   *  src-port: The source port number of the VoIP/VoLTE.

   *  dst-port: The destination port number of VoIP/VoLTE.

   *  src-zone: The source geographical location (e.g., country and
      city) of the VoIP/VoLTE.

   *  dst-zone: The destination geographical location (e.g., country and
      city) of the VoIP/VoLTE.

   *  rule-name: The name of the I2NSF Policy Rule being triggered.

6.4.  System Logs

   System log is a record that is used to monitor the activity of the
   user on the NSF and the status of the NSF.  System Logs

   Characteristics:

   o logs have the
   following characteristics:

   *  acquisition-method: subscription

   o

   *  emission-type: on-change

   o or periodic

   *  dampening-type: on-repetition

7.4.1.

6.4.1.  Access Log

   Access logs record administrators' login, logout, and operations on a
   device.  By analyzing them, security vulnerabilities can be
   identified.  The following information should be included in an
   operation report:

   o  Administrator: Administrator

   *  username: The username that operates on the device

   o  login-ip-address: device.

   *  login-ip: IP address used by an administrator to log in
   o in.

   *  login-mode: Specifies the administrator logs in mode e.g. root,
      user

   o
      administrator, user, and guest.

   *  operation-type: The operation type that the administrator execute,
      e.g., login, logout, configuration, and configuration.

   o  result: Command execution result

   o  content: Operation other.

   *  input: The operation performed by an administrator a user after login.

7.4.2.  The
      operation is a command given by a user.

   *  output: The result after executing the input.

6.4.2.  Resource Utilization Log

   Running reports record the device system's running status, which is
   useful for device monitoring.  The following information should be
   included in running report:

   o

   *  system-status: The current system's running status

   o status.

   *  cpu-usage: Specifies the aggregated CPU usage.

   o

   *  memory-usage: Specifies the memory usage.

   o

   *  disk-id: Specifies the disk ID to identify the storage disk.

   *  disk-usage: Specifies the disk usage.

   o usage of disk-id.

   *  disk-left: Specifies the available disk space left.

   o left of disk-id.

   *  session-number: Specifies total concurrent sessions.

   o

   *  process-number: Specifies total number of systems processes.

   o

   *  interface-id: Specifies the interface ID to identify the network
      interface.

   *  in-traffic-rate: The total inbound traffic rate in pps

   o packets per
      second.

   *  out-traffic-rate: The total outbound traffic rate in pps

   o packets per
      second.

   *  in-traffic-speed: The total inbound traffic speed in bps

   o bits per
      second.

   *  out-traffic-speed: The total outbound traffic speed in bps

7.4.3. bits per
      second.

6.4.3.  User Activity Log

   User activity logs provide visibility into users' online records
   (such as login time, online/lockout duration, and login IP addresses)
   and the actions that users perform.  User activity reports are
   helpful to identify exceptions during a user's login and network
   access activities.

   o

   *  user: Name of a user
   o user.

   *  group: Group to which a user belongs

   o belongs.

   *  login-ip-addr: Login IP address of a user

   o user.

   *  authentication: User authentication mode. e.g., Local
      Authentication, Third-Party Server Authentication, Authentication
      Exemption, SSO Authentication

   o  access: User access mode. e.g., PPP, SVN, LOCAL

   o The method to verify the valid user, i.e., pre-
      configured-key and certificate-authority.

   *  online-duration: Online The duration

   o of a user's activeness (stays in
      login) during a session.

   *  logout-duration: Logout The duration

   o of a user's inactiveness (not in
      login) from the last session.

   *  additional-info: Additional Information for login:

      1.  type: User activities. e.g., Successful User Login, Failed
          Login attempts, User Logout, Successful User Password Change,
          Failed User Password Change, User Lockout, and User Unlocking,
          Unknown Unlocking.

      2.  cause: Cause of a failed user activity

7.5. activity.

6.5.  NSF Logs

   Characteristics:

   o

   NSF logs have the folowing characteristics:

   *  acquisition-method: subscription

   o

   *  emission-type: on-change

   o

   *  dampening-type: on-repetition

7.5.1.  DPI

6.5.1.  Deep Packet Inspection Log

   DPI

   Deep Packet Inspection (DPI) Logs provide statistics on uploaded and
   downloaded files and data, sent and received emails, and alert and block
   blocking records on websites.  It is helpful to learn risky user
   behaviors and why access
   to some URLs is blocked or allowed with an alert record.

   o  attack-type: DPI action types. e.g., File Blocking, Data
      Filtering, and Application Behavior Control

   o  src-user: User source who generates the policy

   o  policy-name: Security policy name that traffic matches
   o  action: Action defined in the file blocking rule, data filtering
      rule, or application behavior control rule that traffic matches.

7.5.2.  Vulnerability Scanning Log

   Vulnerability scanning logs record the victim host and its related
   vulnerability information that should to be fixed.  The following
   information should be included in the report:

   o  victim-ip: IP address of the victim host which has vulnerabilities

   o  vulnerability-id: The vulnerability id

   o  level: The vulnerability level. e.g., high, middle, and low

   o  OS: The operating system of the victim host

   o  service: The service which has vulnerability in the victim host

   o  protocol: The protocol type. and why access to some URLs is blocked or allowed with an
   alert record.

   *  attack-type: DPI action types. e.g., TCP File Blocking, Data
      Filtering, and UDP

   o  port-num: The port number

   o  vulnerability-info: The information about Application Behavior Control.

   *  src-user: User source who generates the vulnerability

   o  fix-suggestion: The fix suggestion to policy.

   *  policy-name: Security policy name that traffic matches.

   *  action: Action defined in the vulnerability.

7.6. file blocking rule, data filtering
      rule, or application behavior control rule that traffic matches.

6.6.  System Counter

   Characteristics:

   o

   System counter has the following characteristics:

   *  acquisition-method: subscription or query

   o
   *  emission-type: periodical

   o periodic

   *  dampening-type: none

7.6.1.

6.6.1.  Interface Counter

   Interface counters provide visibility into traffic into and out of an
   NSF, and bandwidth usage.

   o  The statistics of the interface counters
   should be computed from the start of the service.  When the service
   is reset, the computation of statistics per counter should restart
   from 0.

   *  interface-name: Network interface name configured in NSF

   o NSF.

   *  in-total-traffic-pkts: Total inbound packets

   o packets.

   *  out-total-traffic-pkts: Total outbound packets
   o packets.

   *  in-total-traffic-bytes: Total inbound bytes

   o bytes.

   *  out-total-traffic-bytes: Total outbound bytes

   o bytes.

   *  in-drop-traffic-pkts: Total inbound drop packets

   o packets.

   *  out-drop-traffic-pkts: Total outbound drop packets

   o packets.

   *  in-drop-traffic-bytes: Total inbound drop bytes

   o bytes.

   *  out-drop-traffic-bytes: Total outbound drop bytes

   o bytes.

   *  in-traffic-average-rate: Inbound traffic average rate in pps

   o packets
      per second.

   *  in-traffic-peak-rate: Inbound traffic peak rate in pps

   o packets per
      second.

   *  in-traffic-average-speed: Inbound traffic average speed in bps

   o bits
      per second.

   *  in-traffic-peak-speed: Inbound traffic peak speed in bps

   o bits per
      second.

   *  out-traffic-average-rate: Outbound traffic average rate in pps

   o packets
      per second.

   *  out-traffic-peak-rate: Outbound traffic peak rate in pps

   o packets per
      second.

   *  out-traffic-average-speed: Outbound traffic average speed in bps

   o bits
      per second.

   *  out-traffic-peak-speed: Outbound traffic peak speed in bps

7.7. bits per
      second.

6.7.  NSF Counters

   Characteristics:

   o

   NSF counters have the following characteristics:

   *  acquisition-method: subscription or query

   o

   *  emission-type: periodical

   o periodic

   *  dampening-type: none

7.7.1.

6.7.1.  Firewall Counter

   Firewall counters provide visibility into traffic signatures,
   bandwidth usage, and how the configured security and bandwidth
   policies have been applied.

   o  src-zone: Source security zone of traffic

   o  dst-zone: Destination security zone of traffic
   o  src-region: Source region of traffic

   o  dst-region: Destination region of traffic

   o

   *  src-ip: Source IP address of traffic

   o traffic.

   *  src-user: User who generates traffic

   o the policy.

   *  dst-ip: Destination IP address of traffic

   o traffic.

   *  src-port: Source port of traffic

   o traffic.

   *  dst-port: Destination port of traffic

   o traffic.

   *  protocol: Protocol type of traffic

   o traffic.

   *  app: Application type of traffic

   o traffic.

   *  policy-id: Security policy id that traffic matches

   o matches.

   *  policy-name: Security policy name that traffic matches

   o matches.

   *  in-interface: Inbound interface of traffic

   o traffic.

   *  out-interface: Outbound interface of traffic

   o traffic.

   *  total-traffic: Total traffic volume

   o volume.

   *  in-traffic-average-rate: Inbound traffic average rate in pps

   o packets
      per second.

   *  in-traffic-peak-rate: Inbound traffic peak rate in pps

   o packets per
      second.

   *  in-traffic-average-speed: Inbound traffic average speed in bps

   o bits
      per second.

   *  in-traffic-peak-speed: Inbound traffic peak speed in bps

   o bits per
      second.

   *  out-traffic-average-rate: Outbound traffic average rate in pps

   o packets
      per second.

   *  out-traffic-peak-rate: Outbound traffic peak rate in pps

   o packets per
      second.

   *  out-traffic-average-speed: Outbound traffic average speed in bps

   o bits
      per second.

   *  out-traffic-peak-speed: Outbound traffic peak speed in bps.

7.7.2. bits per
      second.

6.7.2.  Policy Hit Counter

   Policy Hit Counters record the security policy that traffic matches
   and its hit count.  It can check if policy configurations are
   correct.

   o  src-zone: Source security zone of traffic

   o  dst-zone: Destination security zone of traffic

   o  src-region: Source region of the traffic

   o  dst-region: Destination region of the traffic

   o
   and its hit count.  It can check if policy configurations are
   correct.

   *  src-ip: Source IP address of traffic

   o traffic.

   *  src-user: User who generates traffic

   o the policy.

   *  dst-ip: Destination IP address of traffic

   o traffic.

   *  src-port: Source port of traffic

   o traffic.

   *  dst-port: Destination port of traffic

   o traffic.

   *  protocol: Protocol type of traffic

   o traffic.

   *  app: Application type of traffic

   o traffic.

   *  policy-id: Security policy id that traffic matches

   o matches.

   *  policy-name: Security policy name that traffic matches

   o matches.

   *  hit-times: The hit times that the security policy matches the
      specified traffic.

8.

7.  NSF Monitoring Management in I2NSF

   A standard model for monitoring data is required for an administrator
   to check the monitoring data generated by an NSF.  The administrator
   can check the monitoring data through the following process.  When
   the NSF monitoring data that is under the standard format is
   generated, the NSF forwards it to an NSF data collector via the I2NSF
   NSF Monitoring Interface.  The NSF data collector delivers it to
   I2NSF Consumer or Developer's Management System (DMS) so that the
   administrator can know the state of the I2NSF framework.

   In order to communicate with other components, an I2NSF framework
   [RFC8329] requires the interfaces.  The three main interfaces in
   I2NSF framework are used for sending monitoring data as follows:

   o

   *  I2NSF Consumer-Facing Interface
      [I-D.ietf-i2nsf-consumer-facing-interface-dm]: When an I2NSF User
      makes a security policy and forwards it to the Security Controller
      via Consumer-Facing Interface, it can specify the threat-feed for
      threat prevention, the custom list, the malicious code scan group,
      and the event map group.  They can be used as an event to be
      monitored by an NSF.

   o

   *  I2NSF Registration Interface
      [I-D.ietf-i2nsf-registration-interface-dm]: The Network Functions
      Virtualization (NFV) architecture provides the lifecycle
      management of a Virtual Network Function (VNF) via the Ve-Vnfm
      interface.  The role of Ve-Vnfm is to request VNF lifecycle
      management (e.g., the instantiation and de-instantiation of an
      NSF, and load balancing among NSFs), exchange configuration
      information, and exchange status information for a network
      service.  In the I2NSF framework, the DMS manages data about
      resource states and network traffic for the lifecycle management
      of an NSF.  Therefore, the generated monitoring data from NSFs are
      delivered from the NSF data collector to the DMS via either
      Registration Interface or a new interface (e.g., NSF Monitoring
      Interface).  These data are delivered from the DMS to the VNF
      Manager in the Management and Orchestration (MANO) in the NFV
      system [I-D.ietf-i2nsf-applicability].

   o

   *  I2NSF NSF Monitoring Interface [RFC8329]: After a high-level
      security policy from I2NSF User is translated by security policy
      translator [I-D.yang-i2nsf-security-policy-translation] in the
      Security Controller, the translated security policy (i.e., low-
      level policy) is applied to an NSF via NSF-Facing Interface.  The
      monitoring interface data model for an NSF specifies the list of
      events that can trigger Event-Condition-Action (ECA) policies via
      NSF Monitoring Interface.

9.

8.  Tree Structure

   The tree structure of the NSF monitoring YANG module is provided
   below:

   module: ietf-i2nsf-nsf-monitoring
     +--ro i2nsf-counters
     |  +--ro system-interface* [interface-name]
     |  |  +--ro acquisition-method?          identityref
     |  |  +--ro emission-type?               identityref
     |  |  +--ro dampening-type?              identityref
     |  |  +--ro interface-name               string
     |  |  +--ro in-total-traffic-pkts?       yang:counter32
     |  |  +--ro out-total-traffic-pkts?      yang:counter32
     |  |  +--ro in-total-traffic-bytes?      uint64
     |  |  +--ro out-total-traffic-bytes?     uint64
     |  |  +--ro in-drop-traffic-pkts?        yang:counter32
     |  |  +--ro out-drop-traffic-pkts?       yang:counter32
     |  |  +--ro in-drop-traffic-bytes?       uint64
     |  |  +--ro out-drop-traffic-bytes?      uint64
     |  |  +--ro total-traffic?               yang:counter32
     |  |  +--ro in-traffic-average-rate?     uint32
     |  |  +--ro in-traffic-peak-rate?        uint32
     |  |  +--ro in-traffic-average-speed?    uint32
     |  |  +--ro in-traffic-peak-speed?       uint32
     |  |  +--ro out-traffic-average-rate?    uint32
     |  |  +--ro out-traffic-peak-rate?       uint32
     |  |  +--ro out-traffic-average-speed?   uint32
     |  |  +--ro out-traffic-peak-speed?      uint32
     |  |  +--ro message?                     string
     |  |  +--ro vendor-name?                 string
     |  |  +--ro nsf-name?                      string                    union
     |  |  +--ro severity?                    severity
     |  |  +--ro timestamp?                   yang:date-and-time
     |  +--ro nsf-firewall* [policy-name]
     |  |  +--ro acquisition-method?          identityref
     |  |  +--ro emission-type?               identityref
     |  |  +--ro dampening-type?              identityref
     |  |  +--ro policy-name
            -> /nsfi:i2nsf-security-policy/system-policy/system-policy-name /nsfi:i2nsf-security-policy/system-policy-name
     |  |  +--ro src-user?                    string
     |  |  +--ro total-traffic?               yang:counter32
     |  |  +--ro in-traffic-average-rate?     uint32
     |  |  +--ro in-traffic-peak-rate?        uint32
     |  |  +--ro in-traffic-average-speed?    uint32
     |  |  +--ro in-traffic-peak-speed?       uint32
     |  |  +--ro out-traffic-average-rate?    uint32
     |  |  +--ro out-traffic-peak-rate?       uint32
     |  |  +--ro out-traffic-average-speed?   uint32
     |  |  +--ro out-traffic-peak-speed?      uint32
     |  |  +--ro message?                     string
     |  |  +--ro vendor-name?                 string
     |  |  +--ro nsf-name?                     string                    union
     |  |  +--ro severity?                    severity
     |  |  +--ro timestamp?                   yang:date-and-time
     |  +--ro nsf-policy-hits* [policy-name]
     |     +--ro acquisition-method?   identityref
     |     +--ro emission-type?        identityref
     |     +--ro dampening-type?       identityref
     |     +--ro policy-name
             -> /nsfi:i2nsf-security-policy/system-policy/system-policy-name /nsfi:i2nsf-security-policy/system-policy-name
     |     +--ro src-user?             string
     |     +--ro message?              string
     |     +--ro vendor-name?          string
     |     +--ro nsf-name?             string             union
     |     +--ro severity?             severity
     |     +--ro hit-times?            yang:counter32
     |     +--ro timestamp?            yang:date-and-time
     +--rw i2nsf-monitoring-configuration
        +--rw i2nsf-system-detection-alarm
        |  +--rw enabled?        boolean
        |  +--rw system-alarm* [alarm-type]
        |     +--rw alarm-type          enumeration
        |     +--rw threshold?          uint8
        |     +--rw dampening-period?   uint32
        +--rw i2nsf-system-detection-event
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-traffic-flows
        |  +--rw dampening-period?   uint32
        |  +--rw enabled?            boolean
        +--rw i2nsf-nsf-detection-ddos {i2nsf-nsf-detection-ddos}?
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-nsf-detection-session-table-configuration
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-nsf-detection-virus {i2nsf-nsf-detection-virus}?
      |  +--rw enabled?            boolean
      |  +--rw dampening-period?   uint32
      +--rw i2nsf-nsf-detection-intrusion
                      {i2nsf-nsf-detection-intrusion}?
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-nsf-detection-botnet {i2nsf-nsf-detection-botnet}?
      |  +--rw enabled?            boolean
      |  +--rw dampening-period?   uint32
      +--rw i2nsf-nsf-detection-web-attack
                     {i2nsf-nsf-detection-web-attack}?
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-nsf-system-access-log
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-system-res-util-log
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-system-user-activity-log
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-nsf-log-dpi {i2nsf-nsf-log-dpi}?
        |  +--rw enabled?            boolean
        |  +--rw dampening-period?   uint32
        +--rw i2nsf-nsf-log-vuln-scan {i2nsf-nsf-log-vuln-scan}?
      |  +--rw enabled?            boolean
      |  +--rw dampening-period?   uint32
      +--rw i2nsf-counter
           +--rw period?   uint16

     notifications:
       +---n i2nsf-event
       |  +--ro (sub-event-type)?
       |     +--:(i2nsf-system-detection-alarm)
       |     |  +--ro i2nsf-system-detection-alarm
       |     |     +--ro alarm-category?       identityref
       |     |     +--ro component-name?       string
       |     |     +--ro interface-name?       string
       |     |     +--ro interface-state?      enumeration
       |     |     +--ro acquisition-method?   identityref
       |     |     +--ro emission-type?        identityref
       |     |     +--ro dampening-type?       identityref
       |     |     +--ro usage?                uint8
       |     |     +--ro threshold?            uint8
       |     |     +--ro message?              string
       |     |     +--ro vendor-name?          string
       |     |     +--ro nsf-name?             string             union
       |     |     +--ro severity?             severity
       |     +--:(i2nsf-system-detection-event)
       |     |  +--ro i2nsf-system-detection-event
       |     |     +--ro event-category?       identityref
       |     |     +--ro acquisition-method?   identityref
       |     |     +--ro emission-type?        identityref
       |     |     +--ro dampening-type?       identityref
       |     |     +--ro user                  string
       |     |     +--ro group group*                string
       |     |     +--ro login-ip-addr ip-address            inet:ip-address
       |     |     +--ro authentication?       identityref
       |     |     +--ro message?              string
       |     |     +--ro vendor-name?          string
       |     |     +--ro nsf-name?             string             union
       |     |     +--ro severity?             severity
       |     +--:(i2nsf-traffic-flows)
       |     |  +--ro i2nsf-traffic-flows
       |     |     +--ro src-ip?               inet:ip-address
       |     |     +--ro dst-ip?               inet:ip-address
       |     |     +--ro protocol?             identityref
       |     |     +--ro src-port?             inet:port-number
       |     |     +--ro dst-port?             inet:port-number
       |     |     +--ro arrival-rate?         uint32
       |     |     +--ro acquisition-method?   identityref
       |     |     +--ro emission-type?        identityref
       |     |     +--ro dampening-type?       identityref
       |     |     +--ro message?              string
       |     |     +--ro vendor-name?          string
       |     |     +--ro nsf-name?             string             union
       |     |     +--ro severity?             severity
       |     +--:(i2nsf-nsf-detection-session-table)
       |        +--ro i2nsf-nsf-detection-session-table
       |           +--ro current-session?   uint32
       |           +--ro maximum-session?   uint32
       |           +--ro threshold?         uint32
       |           +--ro message?           string
       |           +--ro vendor-name?       string
       |           +--ro nsf-name?          string          union
       |           +--ro severity?          severity
       +---n i2nsf-log
       |  +--ro (sub-logs-type)?
       |     +--:(i2nsf-nsf-system-access-log)
       |     |  +--ro i2nsf-nsf-system-access-log
       |     |     +--ro login-ip              inet:ip-address
       |     |     +--ro administrator? username?             string
       |     |     +--ro login-mode?           login-mode login-role?           login-role
       |     |     +--ro operation-type?       operation-type
       |     |     +--ro result? input?                string
       |     |     +--ro content? output?               string
       |     |     +--ro acquisition-method?   identityref
       |     |     +--ro emission-type?        identityref
       |     |     +--ro dampening-type?       identityref
       |     |     +--ro message?              string
       |     |     +--ro vendor-name?          string
       |     |     +--ro nsf-name?             string             union
       |     |     +--ro severity?             severity
       |     +--:(i2nsf-system-res-util-log)
       |     |  +--ro i2nsf-system-res-util-log
       |     |     +--ro system-status?        string        enumeration
       |     |     +--ro cpu-usage?            uint8
       |     |     +--ro memory-usage?         uint8
       |     |     +--ro disk* [disk-id]
       |     |     |  +--ro disk-id       string
       |     |     |  +--ro disk-usage?   uint8
       |     |     |  +--ro disk-left?    uint8
       |     |     +--ro session-num?          uint8          uint32
       |     |     +--ro process-num?          uint8          uint32
       |     |     +--ro interface* [interface-id]
       |     |     |  +--ro interface-id         string
       |     |     |  +--ro in-traffic-rate?     uint32
       |     |     |  +--ro out-traffic-rate?    uint32
       |     |     |  +--ro in-traffic-speed?    uint32
       |     |     |  +--ro out-traffic-speed?   uint32
       |     |     +--ro acquisition-method?   identityref
       |     |     +--ro emission-type?        identityref
       |     |     +--ro dampening-type?       identityref
       |     |     +--ro message?              string
       |     |     +--ro vendor-name?          string
       |     |     +--ro nsf-name?             string             union
       |     |     +--ro severity?             severity
       |     +--:(i2nsf-system-user-activity-log)
       |        +--ro i2nsf-system-user-activity-log
       |           +--ro acquisition-method?   identityref
       |           +--ro emission-type?        identityref
       |           +--ro dampening-type?       identityref
       |           +--ro user                  string
       |           +--ro group group*                string
       |           +--ro login-ip-addr ip-address            inet:ip-address
       |           +--ro authentication?       identityref
       |           +--ro message?              string
       |           +--ro vendor-name?          string
       |           +--ro nsf-name?             string             union
       |           +--ro severity?             severity
       |           +--ro access?               identityref
     |           +--ro online-duration?      string      uint32
       |           +--ro logout-duration?      string      uint32
       |           +--ro additional-info?      string      enumeration
       +---n i2nsf-nsf-event
          +--ro (sub-event-type)?
             +--:(i2nsf-nsf-detection-ddos) {i2nsf-nsf-detection-ddos}?
             |  +--ro i2nsf-nsf-detection-ddos
             |     +--ro dst-ip?               inet:ip-address attack-type?          identityref
             |     +--ro dst-port?             inet:port-number start-time            yang:date-and-time
             |     +--ro rule-name
            -> /nsfi:i2nsf-security-policy/system-policy/rules/rule-name end-time              yang:date-and-time
             |     +--ro raw-info?             string attack-src-ip*        inet:ip-address
             |     +--ro attack-type?          identityref attack-dst-ip*        inet:ip-prefix
             |     +--ro start-time            yang:date-and-time attack-src-port*      inet:port-number
             |     +--ro end-time              yang:date-and-time attack-dst-port*      inet:port-number
             |     +--ro attack-src-ip?        inet:ip-address rule-name
                       -> /nsfi:i2nsf-security-policy/rules/rule-name
             |     +--ro attack-dst-ip?        inet:ip-address raw-info?             string
             |     +--ro attack-rate?          uint32
             |     +--ro attack-speed?         uint32
             |     +--ro action? action*               log-action
             |     +--ro acquisition-method?   identityref
             |     +--ro emission-type?        identityref
             |     +--ro dampening-type?       identityref
             |     +--ro message?              string
             |     +--ro vendor-name?          string
             |     +--ro nsf-name?             string             union
             |     +--ro severity?             severity
             +--:(i2nsf-nsf-detection-virus)
                        {i2nsf-nsf-detection-virus}?
             |  +--ro i2nsf-nsf-detection-virus
             |     +--ro dst-ip?               inet:ip-address
             |     +--ro dst-port?             inet:port-number
             |     +--ro rule-name
                       -> /nsfi:i2nsf-security-policy/system-policy/rules/rule-name /nsfi:i2nsf-security-policy/rules/rule-name
             |     +--ro raw-info?             string
             |     +--ro src-ip?               inet:ip-address
             |     +--ro src-port?             inet:port-number
             |     +--ro src-zone?             string
             |     +--ro dst-zone?             string
             |     +--ro virus?                identityref
             |     +--ro virus-name?           string
             |     +--ro file-type?            string
             |     +--ro file-name?            string
             |     +--ro os?                   string
             |     +--ro action? action*               log-action
             |     +--ro acquisition-method?   identityref
             |     +--ro emission-type?        identityref
             |     +--ro dampening-type?       identityref
             |     +--ro message?              string
             |     +--ro vendor-name?          string
             |     +--ro nsf-name?             string             union
             |     +--ro severity?             severity
             +--:(i2nsf-nsf-detection-intrusion)
               {i2nsf-nsf-detection-intrusion}?
           |  +--ro i2nsf-nsf-detection-intrusion
           |     +--ro dst-ip?               inet:ip-address
           |     +--ro dst-port?             inet:port-number
           |     +--ro rule-name
            -> /nsfi:i2nsf-security-policy/system-policy/rules/rule-name
           |     +--ro raw-info?             string
           |     +--ro src-ip?               inet:ip-address
           |     +--ro src-port?             inet:port-number
           |     +--ro src-zone?             string
           |     +--ro dst-zone?             string
           |     +--ro protocol?             identityref
           |     +--ro app?                  string
           |     +--ro attack-type?          identityref
           |     +--ro action?               log-action
           |     +--ro attack-rate?          uint32
           |     +--ro attack-speed?         uint32
           |     +--ro acquisition-method?   identityref
           |     +--ro emission-type?        identityref
           |     +--ro dampening-type?       identityref
           |     +--ro message?              string
           |     +--ro vendor-name?          string
           |     +--ro nsf-name?             string
           |     +--ro severity?             severity
           +--:(i2nsf-nsf-detection-botnet)
             {i2nsf-nsf-detection-botnet}?
                         {i2nsf-nsf-detection-intrusion}?
             |  +--ro i2nsf-nsf-detection-botnet i2nsf-nsf-detection-intrusion
             |     +--ro dst-ip?               inet:ip-address
             |     +--ro dst-port?             inet:port-number
             |     +--ro rule-name
                     -> /nsfi:i2nsf-security-policy/system-policy/rules/rule-name /nsfi:i2nsf-security-policy/rules/rule-name
             |     +--ro raw-info?             string
             |     +--ro src-ip?               inet:ip-address
             |     +--ro src-port?             inet:port-number
             |     +--ro src-zone?             string
             |     +--ro dst-zone?             string
             |     +--ro attack-type?          identityref
           |     +--ro protocol?             identityref
             |     +--ro botnet-name?          string app?                  identityref
             |     +--ro role?                 string attack-type?          identityref
             |     +--ro action? action*               log-action
             |     +--ro botnet-pkt-num?       uint8 attack-rate?          uint32
             |     +--ro os?                   string attack-speed?         uint32
             |     +--ro acquisition-method?   identityref
             |     +--ro emission-type?        identityref
             |     +--ro dampening-type?       identityref
             |     +--ro message?              string
             |     +--ro vendor-name?          string
             |     +--ro nsf-name?             string             union
             |     +--ro severity?             severity
             +--:(i2nsf-nsf-detection-web-attack)
                       {i2nsf-nsf-detection-web-attack}?
             |  +--ro i2nsf-nsf-detection-web-attack
             |     +--ro dst-ip?               inet:ip-address
             |     +--ro dst-port?             inet:port-number
             |     +--ro rule-name
                       -> /nsfi:i2nsf-security-policy/system-policy/rules/rule-name /nsfi:i2nsf-security-policy/rules/rule-name
             |     +--ro raw-info?             string
             |     +--ro src-ip?               inet:ip-address
             |     +--ro src-port?             inet:port-number
             |     +--ro src-zone?             string
             |     +--ro dst-zone?             string
             |     +--ro attack-type?          identityref
             |     +--ro request-method?       identityref
             |     +--ro req-uri?              string
             |     +--ro uri-category?         string
           |     +--ro filtering-type*       identityref
             |     +--ro rsp-code? req-user-agent?       string
             |     +--ro req-clientapp? req-cookie?           string
             |     +--ro req-cookies? req-host?             string
             |     +--ro req-host? response-code?        string
             |     +--ro acquisition-method?   identityref
             |     +--ro emission-type?        identityref
             |     +--ro dampening-type?       identityref
             |     +--ro action? action*               log-action
             |     +--ro message?              string
             |     +--ro vendor-name?          string
             |     +--ro nsf-name?             string             union
             |     +--ro severity?             severity
           +--:(i2nsf-nsf-log-vuln-scan) {i2nsf-nsf-log-vuln-scan}?
           |  +--ro i2nsf-nsf-log-vuln-scan
             +--:(i2nsf-nsf-detection-voip-volte)
                        {i2nsf-nsf-detection-voip-volte}?
             |  +--ro vulnerability-id?     uint8 i2nsf-nsf-detection-voip-volte
             |     +--ro victim-ip? dst-ip?                 inet:ip-address
             |     +--ro protocol?             identityref
           |     +--ro port-num? dst-port?               inet:port-number
             |     +--ro level?                severity rule-name
                       -> /nsfi:i2nsf-security-policy/rules/rule-name
             |     +--ro os? raw-info?               string
             |     +--ro vulnerability-info?   string src-ip?                 inet:ip-address
             |     +--ro fix-suggestion?       string src-port?               inet:port-number
             |     +--ro service? src-zone?               string
             |     +--ro acquisition-method?   identityref
           |     +--ro emission-type?        identityref
           |     +--ro dampening-type?       identityref
           |     +--ro message? dst-zone?               string
             |     +--ro vendor-name? source-voice-id*        string
             |     +--ro nsf-name? destination-voice-id*   string
             |     +--ro severity?             severity user-agent*             string
             +--:(i2nsf-nsf-log-dpi) {i2nsf-nsf-log-dpi}?
                +--ro i2nsf-nsf-log-dpi
                   +--ro attack-type?          dpi-type
                   +--ro acquisition-method?   identityref
                   +--ro emission-type?        identityref
                   +--ro dampening-type?       identityref
                   +--ro policy-name
                     -> /nsfi:i2nsf-security-policy/system-policy/system-policy-name /nsfi:i2nsf-security-policy/system-policy-name
                   +--ro src-user?             string
                   +--ro message?              string
                   +--ro vendor-name?          string
                   +--ro nsf-name?             string             union
                   +--ro severity?             severity

               Figure 1: Information Model for NSF Monitoring

10.

9.  YANG Data Model

   This section describes a YANG module of I2NSF NSF Monitoring.  The
   data model provided in this document uses identities to be used to
   get information of the monitored of an NSF's monitoring data.  Every
   identity used in the document gives information or status about the
   current situation of an NSF.  This YANG module imports from
   [RFC6991], and makes references to [RFC0768][RFC0791] [RFC0792][RFC0793][RFC0956]
   [RFC0959][RFC2616][RFC4443] [RFC8200][RFC8632][RFC8641].
   [RFC0792][RFC0793] [RFC0959][RFC4443] [RFC8200][RFC8641]
   [IANA-HTTP-Status-Code] [IANA-Media-Types].

   <CODE BEGINS> file "ietf-i2nsf-nsf-monitoring@2021-04-29.yang" "ietf-i2nsf-nsf-monitoring@2021-08-24.yang"
   module ietf-i2nsf-nsf-monitoring {
     yang-version 1.1;
     namespace
       "urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring";
     prefix
       nsfmi;
     import ietf-inet-types{
       prefix inet;
       reference
         "Section 4 of RFC 6991";
     }
     import ietf-yang-types {
       prefix yang;
       reference
         "Section 3 of RFC 6991";

     }
     import ietf-i2nsf-policy-rule-for-nsf {
       prefix nsfi;
       reference
         "Section 4.1 of draft-ietf-i2nsf-nsf-facing-interface-dm-12"; draft-ietf-i2nsf-nsf-facing-interface-dm-13";
     }
     organization
       "IETF I2NSF (Interface to Network Security Functions)
        Working Group";
     contact
       "WG Web: <http://tools.ietf.org/wg/i2nsf>
        WG List: <mailto:i2nsf@ietf.org>

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

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

     description
       "This module is a YANG module for I2NSF NSF Monitoring.

        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
        (RFC 2119) (RFC 8174) when, and only when, they appear
        in all capitals, as shown here.

        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.";

     revision "2021-04-29" "2021-08-24" {
       description "Latest revision";
       reference
         "RFC XXXX: I2NSF NSF Monitoring Interface YANG Data Model";

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

     /*
      * Typedefs
      */

     typedef severity {
       type enumeration {
         enum critical {
           description
             "The 'critical' severity level indicates that
              an immediate corrective action is required.
              A 'critical' severity is reported when a service
              becomes totally out of service and must be restored.";
         }
         enum high {
           description
             "The 'high' severity level indicates that
              an urgent corrective action is required.
              A 'high' severity is reported when there is
              a severe degradation in the capability of the
              service and its full capability must be restored.";
         }
         enum middle {
           description
             "The 'middle' severity level indicates the
              existence of a non-service-affecting fault
              condition and corrective action should be done
              to prevent a more serious fault. The 'middle'
              severity is reported when the detected problem
              is not degrading the capability of the service service, but
              some service degradation might happen if not
              prevented.";
         }
         enum low {
           description
             "The 'low' severity level indicates the detection
              of a potential fault before any effect is felt. observed.
              The 'low' severity is reported when an action should
              be done before a fault happen.";
         }
       }
       description
         "An indicator representing severity level. levels. The severity level
          levels starting from the highest are critical, high, middle,
          and low.";
     reference
       "RFC 8632: A YANG Data Model for Alarm Management -
        The severity levels are defined.";

     }

     typedef log-action {
       type enumeration {
         enum allow {
           description
             "If action is allowed";
         }
         enum alert {
           description
             "If action is alert";
         }
         enum block {
           description
             "If action is block";
         }
         enum discard {
           description
             "If action is discarded";
         }
         enum declare {
           description
             "If action is declared";
         }
         enum block-ip {
           description
             "If action is block-ip";
         }
         enum block-service{
           description
             "If action is block-service";
         }
       }
       description
         "The type representing action for logging.";
     }

     typedef dpi-type{
       type enumeration {
         enum file-blocking{
           description
             "DPI for blocking file"; preventing the specified file types from flowing
              in the network.";
         }
         enum data-filtering{
           description
             "DPI for filtering data"; preventing sensitive information (e.g., Credit
              Card Number or Social Security Numbers) leaving a
              protected network.";
         }
         enum application-behavior-control{
           description
             "DPI for controlling filtering packet based on the application behavior"; or
              network behavior analysis to identify malicious or
              unusual activity.";
         }
       }
       description
         "The type of deep packet inspection."; Deep Packet Inspection (DPI).
          The defined types are file-blocking, data-filtering, and
          application-behavior-control.";
     }

     typedef operation-type{
       type enumeration {
         enum login{ login {
           description
           "Login operation";
             "The operation type is Login.";
         }
         enum logout {
           description
             "The operation type is Logout.";
         }
         enum logout{ configuration {
           description
           "Logout operation";
             "The operation type is Configuration. The configuration
              operation includes the command for writing a new
              configuration and modifying an existing configuration.";
         }
         enum configuration{ other {
           description
           "Configuration operation";
             "The operation type is Other operation. This other
              includes all operations done by a user except login,
              logout, and configuration.";
         }
       }
       description
         "The type of operation done by a user during a session."; session.
          The user operation is not considering their privileges.";
     }

     typedef login-mode{ login-role {
       type enumeration {
         enum root{ administrator {
           description
           "Root login-mode";
             "Administrator (i.e., Super User) login role.

              Non-restricted role.";
         }
         enum user{ user {
           description
             "User login-mode"; login role. Semi-restricted role, some data and
              configurations are available but confidential or important
              data and configuration are restricted.";
         }
         enum guest{ guest {
           description
             "Guest login-mode"; login role. Restricted role, only few read data are
              available and write configurations are restricted.";
         }
       }
       description
         "The authorization login-mode done by role of a user."; user after login.";
     }

     /*
      * Identity
      */

     identity characteristics {
       description
         "Base identity for monitoring information
          characteristics";
     }
     identity acquisition-method {
       base characteristics;
       description
         "The type of acquisition-method. It can be multiple
          types at once.";
     }
     identity subscription {
       base acquisition-method;
       description
         "The acquisition-method type is subscription.";
     }
     identity query {
       base acquisition-method;
       description
         "The acquisition-method type is query.";
     }
     identity emission-type {
       base characteristics;
       description
         "The type of emission-type.";
     }
     identity periodical periodic {
       base emission-type;
       description
         "The emission-type type is periodical."; periodic.";
     }
     identity on-change {
       base emission-type;
       description
         "The emission-type type is on-change.";
     }
     identity dampening-type {
       base characteristics;
       description
         "The type of dampening-type."; message dampening to stop the rapid transmission
          of messages. The dampening types are on-repetition and
          no-dampening";
     }
     identity no-dampening {
       base dampening-type;
       description
         "The dampening-type is no-dampening."; no-dampening. No-dampening type does
          not limit the transmission for the messages of the same
          type.";
     }
     identity on-repetition {
       base dampening-type;
       description
         "The dampening-type is on-repetition.";
   }
   identity none {
     base dampening-type;
     description
       "The dampening-type is none."; on-repetition. On-repetition type limits
          the transmitted on-change message to one message at a certain
          interval.";
     }

     identity authentication-mode {
       description
       "User
         "The authentication mode types: for a user to connect to the NSF,
          e.g., Local Authentication,
        Third-Party Server Authentication,
        Authentication Exemption, or Single Sign-On (SSO)
        Authentication."; pre-configured-key and certificate-authority";
     }
     identity local-authentication pre-configured-key {
       base authentication-mode;
       description
       "Authentication-mode : local
         "The pre-configured-key is an authentication using a key
          authentication.";
     }
     identity third-party-server-authentication certificate-authority {
       base authentication-mode;
       description
       "If authentication-mode
         "The certificate-authority (CA) is
        third-party-server-authentication"; an authentication using a
          digital certificate.";

     }

     identity exemption-authentication event {
     base authentication-mode;
       description
       "If authentication-mode is
        exemption-authentication";
         "Base identity for I2NSF events.";
     }

     identity sso-authentication system-event {
       base authentication-mode; event;
       description
       "If authentication-mode is
        sso-authentication";
         "Identity for system event";
     }

     identity alarm-type system-alarm {
       base event;
       description
         "Base identity for detectable system alarm types";
     }

     identity mem-usage-alarm memory-alarm {
       base alarm-type; system-alarm;
       description
         "A memory alarm is alerted.";
     }
     identity cpu-usage-alarm cpu-alarm {
       base alarm-type; system-alarm;
       description
         "A CPU alarm is alerted.";
     }
     identity disk-usage-alarm disk-alarm {
       base alarm-type; system-alarm;
       description
         "A disk alarm is alerted.";
     }
     identity hw-failure-alarm hardware-alarm {
       base alarm-type; system-alarm;
       description
         "A hardware alarm (i.e., hardware failure) is alerted.";
     }
     identity ifnet-state-alarm interface-alarm {
       base alarm-type; system-alarm;
       description
         "An interface alarm is alerted.";
     }

     identity event-type access-violation {
       base system-event;
       description
       "Base identity for detectable
         "The access-violation system event types"; is an event when a user
          tries to access (read or write) any information above their
          privilege.";
     }
     identity access-denied configuration-change {
       base event-type; system-event;
       description
         "The configuration-change system event is access-denied."; an event when a user
          adds a new configuration or modify an existing configuration
          (write configuration).";
     }

     identity attack-type {
       description
         "The root ID of attack-based notification
          in the notification taxonomy";
     }
     identity nsf-attack-type {
       base attack-type;
       description
         "This ID is intended to be used
          in the context of NSF event.";
     }

     identity virus-type {
       base nsf-attack-type;
       description
         "The type of virus. It can be multiple types at once.
          This attack type is associated with a detected
          system-log virus-attack.";
     }
     identity config-change trojan {
       base event-type; virus-type;
       description
         "The system event virus type is config-change."; a trojan. Trojan is able to disguise the
          intent of the files or programs to misleads the users.";
     }
     identity attack-type worm {
       base virus-type;
       description
         "The virus type is a worm. Worm can self-replicate and
          spread through the network automatically.";
     }
     identity macro {
       base virus-type;
       description
         "The root ID virus type is a macro virus. Macro causes a series of attack-based notification
        in
          threats automatically after the notification taxonomy"; program is executed.";

     }
     identity system-attack-type boot-sector {
       base attack-type; virus-type;
       description
       "This ID
         "The virus type is intended to be used
        in a boot sector virus. Boot sector is a virus
          that infects the context core of system events."; the computer, affecting the startup
          process.";
     }
     identity nsf-attack-type polymorphic {
       base attack-type; virus-type;
       description
       "This ID
         "The virus type is intended a polymorphic virus. Polymorphic can
          modify its version when it replicates, making it hard to be used
        in the context of NSF event.";
          detect.";
     }
     identity botnet-attack-type overwrite {
       base nsf-attack-type; virus-type;
       description
       "This indicates that this attack
         "The virus type is botnet.
        The usual semantic and taxonomy is missing an overwrite virus. Overwrite can remove
          existing software and a name is used."; replace it with malicious code by
          overwriting it.";
     }
     identity virus-type resident {
       base nsf-attack-type; virus-type;
       description
         "The type of virus. It caan be multiple types at once.
        This attack type virus-type is associated with a detected
        system-log virus-attack."; resident virus. Resident saves itself in
          the computer's memory and infects other files and software.";
     }
     identity trojan non-resident {
       base virus-type;
       description
         "The detected virus type virus-type is trojan."; a non-resident virus. Non-resident attaches
          directly to an executable file and enters the device when
          executed.";
     }
     identity worm multipartite {
       base virus-type;
       description
         "The detected virus type virus-type is worm."; a multipartite virus. Multipartite attacks
          both the boot sector and executables files of a computer.";
     }
     identity macro spacefiller {
       base virus-type;
       description
         "The detected virus type virus-type is macro."; a spacefiller virus. Spacefiller fills empty
          spaces of a file or software with malicious code.";
     }
     identity intrusion-attack-type {
       base nsf-attack-type;
       description
         "The attack type is associated with a detected
          system-log intrusion.";
     }
     identity brute-force {
       base intrusion-attack-type;
       description
         "The intrusion type is brute-force.";
     }
     identity buffer-overflow {
       base intrusion-attack-type;
       description
         "The intrusion type is buffer-overflow.";
     }
     identity web-attack-type {
       base nsf-attack-type;
       description
         "The attack type is associated with a detected
          system-log web-attack.";
     }
     identity command-injection {
       base web-attack-type;
       description
         "The detected web attack type is command injection.";
     }
     identity xss {
       base web-attack-type;
       description
         "The detected web attack type is XSS.";
     }
     identity csrf {
       base web-attack-type;
       description
         "The detected web attack type is CSRF.";
     }

     identity flood-type ddos-type {
       base nsf-attack-type;
       description
         "Base identity for detectable flood types";
     }
     identity syn-flood {
       base flood-type; ddos-type;
       description
         "A SYN flood is detected.";
     }
     identity ack-flood {
       base flood-type; ddos-type;
       description
         "An ACK flood is detected.";
     }
     identity syn-ack-flood {
       base flood-type; ddos-type;
       description
         "A SYN-ACK flood is detected.";
     }
     identity fin-rst-flood {
       base flood-type; ddos-type;
       description
         "A FIN-RST flood is detected.";
     }
     identity tcp-con-flood {
       base flood-type; ddos-type;
       description
         "A TCP connection flood is detected.";
     }
     identity udp-flood {
       base flood-type; ddos-type;
       description
         "A UDP flood is detected.";
     }
     identity icmp-flood icmpv4-flood {
       base flood-type; ddos-type;
       description
       "Either an
         "An ICMPv4 or flood is detected.";
     }
     identity icmpv6-flood {
       base ddos-type;
       description
         "An ICMPv6 flood is detected.";
     }
     identity icmpv4-flood http-flood {
       base flood-type; ddos-type;
       description
         "An ICMPv4 HTTP flood is detected.";
     }
     identity icmpv6-flood https-flood {
       base flood-type; ddos-type;
       description
         "An ICMPv6 HTTPS flood is detected.";
     }
     identity http-flood dns-query-flood {
       base ddos-type;
       description
         "A Domain Name System (DNS) query flood is detected.";
     }
     identity dns-reply-flood {
       base ddos-type;
       description
        "A Domain Name System (DNS) reply flood is detected.";
     }
     identity sip-flood {
       base ddos-type;
       description
         "A Session Initiation Protocol (SIP) flood is detected.";
     }
     identity ssl-flood {
       base flood-type; ddos-type;
       description
         "An HTTP Secure Sockets Layer (SSL) flood is detected."; detected";
     }
     identity ntp-amp-flood {
       base ddos-type;
       description
         "A Network Time Protocol (NTP) amplification is detected";
     }

     identity request-method {
       description
         "A set of request types in HTTP (if applicable).";
     }
     identity put {
       base request-method;
       description
         "The detected request type is PUT.";
       reference
         "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content - Request Method PUT";
     }
     identity https-flood post {
       base flood-type; request-method;
       description
       "An HTTPS flood
         "The detected request type is detected."; POST.";
       reference
         "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content - Request Method POST";
     }
     identity dns-query-flood get {
       base flood-type; request-method;
       description
       "A DNS query flood
         "The detected request type is detected."; GET.";
       reference
         "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content - Request Method GET";
     }
     identity dns-reply-flood head {
       base flood-type; request-method;
       description
      "A DNS reply flood
         "The detected request type is detected."; HEAD.";
       reference
         "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content - Request Method HEAD";
     }
     identity sip-flood delete {
       base flood-type; request-method;
       description
       "An SIP flood
         "The detected request type is detected."; DELETE.";
       reference
         "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content - Request Method DELETE";
     }
     identity req-method connect {
       base request-method;
       description
       "A set of
         "The detected request types (if applicable).
        For instance, PUT or GET in HTTP."; type is CONNECT.";
       reference
         "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content - Request Method CONNECT";
     }
     identity put-req options {
       base req-method; request-method;
       description
         "The detected request type is PUT."; OPTIONS.";
       reference
         "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content - Request Method OPTIONS";
     }
     identity get-req trace {
       base req-method; request-method;
       description
         "The detected request type is GET."; TRACE.";
       reference
         "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content - Request Method TRACE";
     }

     identity filter-type {
       description
         "The type of filter used to detect an attack,
          for example, a web-attack.  It can be applicable to
          more than web-attacks.  It can be more than one type."; web-attacks.";
     }
     identity whitelist allow-list {
       base filter-type;
       description
         "The applied filter type is whitelist.";
   }
   identity blacklist {
     base filter-type;
     description
       "The applied an allow list. This filter type is blacklist."; blocks
          all connection except the specified list.";
     }
     identity user-defined deny-list {
       base filter-type;
       description
         "The applied filter type is user-defined.";
   }
   identity malicious-category {
     base filter-type;
     description
       "The applied a deny list. This filter is malicious category."; opens all
          connection except the specified list.";
     }
     identity unknown-filter {
       base filter-type;
       description
         "The applied filter is unknown.";
     }

     identity access-mode {
     description
       "Base identity for detectable access mode.";
   }
   identity ppp {
     base access-mode;
     description
       "Access-mode: ppp";
   }
   identity svn {
     base access-mode;
     description
       "Access-mode: svn";
   }
   identity local {
     base access-mode;
     description
       "Access-mode: local";
   }

   identity protocol-type protocol {
       description
         "An identity used to enable type choices in leaves
          and leaflists with respect to protocol metadata."; metadata. This is used
          to identify the type of protocol that goes through the NSF.";
     }
     identity tcp ip {
       base ipv4;
     base ipv6; protocol;
       description
       "TCP
         "General IP protocol type.";
       reference
         "RFC 793: Transmission Control Protocol"; 791: Internet Protocol
          RFC 8200: Internet Protocol, Version 6 (IPv6)";
     }
     identity udp ipv4 {
       base ipv4;
     base ipv6; ip;
       description
       "UDP
         "IPv4 protocol type.";
       reference
         "RFC 768: User Datagram 791: Internet Protocol";
     }
     identity icmp ipv6 {
       base ipv4;
     base ipv6; ip;
       description
       "General ICMP
         "IPv6 protocol type.";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)";
     }
     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"; Specification
          - ICMPv6";
     }
     identity icmpv4 {
       base ipv4; icmp;
       description
         "ICMPv4 protocol type.";
       reference
         "RFC 791: Internet Protocol
          RFC 792: Internet Control Message Protocol";
     }
     identity icmpv6 {
       base ipv6; icmp;
       description
         "ICMPv6 protocol type.";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)
          RFC 4443: Internet Control Message Protocol (ICMPv6)
          for the Internet Protocol Version 6 (IPv6)
          Specification";
     }
     identity ip transport-protocol {
       base protocol-type; protocol;
       description
       "General IP
         "Base identity for Layer 4 protocol condition capabilities,
          e.g., TCP, UDP, SCTP, DCCP, and ICMP";
     }
     identity tcp {
       base transport-protocol;
       description
         "TCP protocol type.";
       reference
         "RFC 791: Internet Protocol
        RFC 8200: Internet Protocol, Version 6 (IPv6)"; 793: Transmission Control Protocol";
     }
     identity ipv4 udp {
       base ip; transport-protocol;
       description
       "IPv4
         "UDP protocol type.";
       reference
         "RFC 791: Internet 768: User Datagram Protocol";
     }
     identity ipv6 sctp {
       base ip; transport-protocol;
       description
       "IPv6 protocol type.";
         "Identity for SCTP condition capabilities";
       reference
         "RFC 8200: Internet Protocol, Version 6 (IPv6)"; 4960: Stream Control Transmission Protocol";
     }
     identity dccp {
       base transport-protocol;
       description
         "Identity for DCCP condition capabilities";
       reference
         "RFC 4340: Datagram Congestion Control Protocol";
     }
     identity application-protocol {
       base protocol;
       description
         "Base identity for Application protocol, e.g., HTTP, FTP";
     }
     identity http {
       base tcp; application-protocol;
       description
       "HTPP
         "HTTP protocol type.";
       reference
       "RFC 2616:
         "RFC7230: Hypertext Transfer Protocol"; Protocol (HTTP/1.1): Message
          Syntax and Routing
          RFC7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content";
     }
     identity https {
       base application-protocol;
       description
         "HTTPS protocol type.";
       reference
         "RFC7230: Hypertext Transfer Protocol (HTTP/1.1): Message
          Syntax and Routing
          RFC7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics
          and Content";
     }
     identity ftp {
       base tcp; application-protocol;
       description
         "FTP protocol type.";
       reference
         "RFC 959: File Transfer Protocol";
     }
     identity ssh {
       base application-protocol;
       description
         "SSH protocol type.";
       reference
         "RFC 959: File Transfer 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 smtp.";
       reference
         "RFC 5321: Simple Mail Transfer Protocol (SMTP)";
     }
     identity sftp {
       base application-protocol;
       description
         "The identity for sftp.";
       reference
         "RFC 913: Simple File Transfer Protocol (SFTP)";
     }
     identity pop3 {
       base application-protocol;
       description
         "The identity for pop3.";
       reference
         "RFC 1081: Post Office Protocol -Version 3 (POP3)";
     }

     /*
      * Grouping
      */

     grouping timestamp {
       description
         "Grouping for identifying the time of the message.";
       leaf timestamp {
         type yang:date-and-time;
         description
           "Specify the time of a message being delivered.";
       }
     }
     grouping common-monitoring-data {
       description
         "A set of common monitoring data that is needed
         as the basic information.";
       leaf message {
         type string;
         description
           "This is a freetext annotation for
            monitoring a notification's content.";
       }
       leaf vendor-name {
         type string;
         description
           "The name of the NSF vendor"; vendor. The string is unrestricted to
            identify the provider or vendor of the NSF.";
       }
       leaf nsf-name {
         type union {
           type string;
           type inet:ip-address;
         }
         description
           "The name (or IP) or IP address of the NSF generating the message.
            If the given nsf-name is not IP address, the name can be an
            arbitrary string including FQDN (Fully Qualified Domain
            Name). The name MUST be unique for different NSF to
            identify the NSF that generates the message.";
       }
       leaf severity {
         type severity;
         description
           "The severity of the alarm such as critical, high,
            middle, and low.";
       }
     }
     grouping characteristics {
       description
         "A set of characteristics of a notification.";
       leaf acquisition-method {
         type identityref {
           base acquisition-method;
         }
         description
           "The acquisition-method for characteristics";
       }
       leaf emission-type {
         type identityref {
           base emission-type;

         }
        description
           "The emission-type for characteristics";
       }
       leaf dampening-type {
         type identityref {
           base dampening-type;
         }
         description
           "The dampening-type for characteristics";
       }
     }
     grouping i2nsf-system-alarm-type-content {
       description
         "A set of contents for alarm type notification.";
       leaf usage {
         type uint8 {
           range "0..100";
         }
         units "percent";
         description
           "Specifies the used percentage";
       }
       leaf threshold {
         type uint8 {
           range "0..100";
         }
         units "percent";
         description
           "The threshold percentage triggering the alarm or
            the event";
       }
     }
     grouping i2nsf-system-event-type-content {
       description
         "System event metadata associated with system events
          caused by user activity.";
       leaf user {
         type string;
         mandatory true;
         description
           "The name of a user";
       }
     leaf
       leaf-list group {
         type string;
       mandatory true;
         description
           "The group group(s) to which a user belongs.";
       }
       leaf login-ip-addr ip-address {
         type inet:ip-address;
         mandatory true;
         description
           "The login IPv4 (or IPv6) address of a user."; user that trigger the
            event.";
       }
       leaf authentication {
         type identityref {
           base authentication-mode;
         }
         description
           "The authentication-mode for authentication"; of a user.";
       }
     }
     grouping i2nsf-nsf-event-type-content {
       description
         "A set of common IPv4 (or IPv6)-related NSF event
          content elements";
       leaf dst-ip {
         type inet:ip-address;
         description
           "The destination IPv4 (IPv6) address of the packet";
       }
       leaf dst-port {
         type inet:port-number;
         description
           "The destination port of the packet";
       }
       leaf rule-name {
         type leafref {
           path
           "/nsfi:i2nsf-security-policy/nsfi:system-policy"
             "/nsfi:i2nsf-security-policy"
            +"/nsfi:rules/nsfi:rule-name";
         }
         mandatory true;
         description
           "The name of the rule I2NSF Policy Rule being triggered";
       }
       leaf raw-info {
         type string;
         description
           "The information describing the packet
            triggering the event.";
       }
     }
     grouping i2nsf-nsf-event-type-content-extend {
       description
         "A set of extended common IPv4 (or IPv6)-related NSF
          event content elements";
       uses i2nsf-nsf-event-type-content;
       leaf src-ip {
         type inet:ip-address;
         description
           "The source IPv4 (or IPv6) address of the packet";
       }
       leaf src-port {
         type inet:port-number;
         description
           "The source port of the packet";
       }
       leaf src-zone {
         type string {
           length "1..100";
           pattern "[0-9a-zA-Z ]*";
         }
         description
           "The source security zone geographical location (e.g., country and city) of
            the packet"; packet.";
       }
       leaf dst-zone {
         type string {
           length "1..100";
           pattern "[0-9a-zA-Z ]*";
         }
         description
           "The destination security zone geographical location (e.g., country and
            city) of the packet"; packet.";
       }
     }
     grouping log-action {
       description
         "A grouping for logging action.";
     leaf
       leaf-list action {
         type log-action;
         description
           "Action type: allow, alert, block, discard, declare,
            block-ip, block-service";
       }
     }
     grouping attack-rates {
       description
         "A set of traffic rates for monitoring attack traffic
          data";
       leaf attack-rate {
         type uint32;
         units "pps";
         description
           "The PPS average packets per second (pps) rate of attack
            traffic";
       }
       leaf attack-speed {
         type uint32;
         units "bps";
         description
           "The BPS average bits per second (bps) speed of attack traffic";
       }
     }
     grouping traffic-rates {
       description
         "A set of traffic rates for statistics data";
       leaf total-traffic {
         type yang:counter32;
         units "packets";
         description
         "Total traffic";
           "The total number of traffic packets (in and out) in the
            NSF.";
       }
       leaf in-traffic-average-rate {
         type uint32;
         units "pps";
         description
           "Inbound traffic average rate in packets per second (pps)"; (pps).
            The average is calculated from the start of the NSF service
            until the generation of this record.";
       }
       leaf in-traffic-peak-rate {
         type uint32;
         units "pps";
         description
           "Inbound traffic peak rate in packets per second (pps)"; (pps).";
       }
       leaf in-traffic-average-speed {
         type uint32;
         units "bps";
         description
           "Inbound traffic average speed in bits per second (bps)"; (bps).
            The average is calculated from the start of the NSF service
            until the generation of this record.";
       }
       leaf in-traffic-peak-speed {
         type uint32;
         units "bps";
         description
           "Inbound traffic peak speed in bits per second (bps)"; (bps).";
       }
       leaf out-traffic-average-rate {
         type uint32;
         units "pps";
         description
           "Outbound traffic average rate in packets per second (pps)"; (pps).
            The average is calculated from the start of the NSF service
            until the generation of this record.";
       }
       leaf out-traffic-peak-rate {
         type uint32;
         units "pps";
         description
          "Outbound traffic peak rate in packets per Second (pps)"; (pps).";
       }
       leaf out-traffic-average-speed {
         type uint32;
         units "bps";
         description
           "Outbound traffic average speed in bits per second (bps)"; (bps).
            The average is calculated from the start of the NSF service
            until the generation of this record.";
       }
       leaf out-traffic-peak-speed {
         type uint32;
         units "bps";
         description
           "Outbound traffic peak speed in bits per second (bps)"; (bps).";
       }
     }
     grouping i2nsf-system-counter-type-content{
       description
         "A set of counters for an interface traffic data.";
       leaf interface-name {
         type string;
         description
           "Network interface name configured in an NSF";
       }
       leaf in-total-traffic-pkts {
         type yang:counter32;
         description
           "Total inbound packets";
       }
       leaf out-total-traffic-pkts {
         type yang:counter32;
         description
           "Total outbound packets";

       }
       leaf in-total-traffic-bytes {
         type uint64;
         units "bytes";
         description
           "Total inbound bytes";
       }
       leaf out-total-traffic-bytes {
         type uint64;
         units "bytes";
         description
           "Total outbound bytes";
       }
       leaf in-drop-traffic-pkts {
         type yang:counter32;
         description
           "Total inbound drop packets";
       }
       leaf out-drop-traffic-pkts {
         type yang:counter32;
         description
           "Total outbound drop packets";
       }
       leaf in-drop-traffic-bytes {
         type uint64;
         units "bytes";
         description
           "Total inbound drop bytes";
       }
       leaf out-drop-traffic-bytes {
         type uint64;
         units "bytes";
         description
           "Total outbound drop bytes";
       }
       uses traffic-rates;
     }

     grouping i2nsf-nsf-counters-type-content{
       description
         "A set of contents of a policy in an NSF.";
       leaf policy-name {
         type leafref {
           path
           "/nsfi:i2nsf-security-policy/nsfi:system-policy"
             "/nsfi:i2nsf-security-policy"
            +"/nsfi:system-policy-name";
         }
         mandatory true;
         description
           "The name of the policy being triggered";
       }
       leaf src-user{
         type string;
         description
         "User
           "The I2NSF User's name who generates the policy"; policy.";
       }
     }

     grouping enable-notification {
       description
         "A grouping for enabling or disabling notification";
       leaf enabled {
         type boolean;
         default "true";
         description
           "Enables or Disables the notification.
            If 'true', then the notification is enabled.
            If 'false, then the notification is disabled.";
       }
     }

     grouping dampening {
       description
         "A grouping for dampening period of notification.";
       leaf dampening-period {
         type uint32;
         units "centiseconds";
         default "0";
         description
           "Specifies the minimum interval between the assembly of
            successive update records for a single receiver of a
            subscription. Whenever subscribed objects change and
            a dampening-period interval (which may be zero) has
            elapsed since the previous update record creation for
            a receiver, any subscribed objects and properties
            that have changed since the previous update record
            will have their current values marshalled and placed
            in a new update record. But if the subscribed objects change
            when the dampening-period is active, it should update the
            record without sending the notification until the dampening-
            period is finished. If multiple changes happen during the
            active dampening-period, it should update the record with
            the latest data. And at the end of the dampening-period, it
            should send the record as a notification with the latest
            updated record and restart the countdown.";
         reference
           "RFC 8641:  Subscription to YANG Notifications for
            Datastore Updates - Section 5.";
       }
     }

     /*
      * Feature Nodes
      */

     feature i2nsf-nsf-detection-ddos {
       description
         "This feature means it supports I2NSF nsf-detection-ddos
          notification";
     }
     feature i2nsf-nsf-detection-virus {
       description
         "This feature means it supports I2NSF nsf-detection-virus
          notification";
     }
     feature i2nsf-nsf-detection-intrusion {
       description
         "This feature means it supports I2NSF nsf-detection-intrusion
          notification";
     }
     feature i2nsf-nsf-detection-botnet {
     description
       "This feature means it supports I2NSF nsf-detection-botnet
        notification";
   }
   feature i2nsf-nsf-detection-web-attack {
       description
         "This feature means it supports I2NSF nsf-detection-web-attack
          notification";
     }
     feature i2nsf-nsf-log-dpi i2nsf-nsf-detection-voip-volte {
       description
         "This feature means it supports I2NSF nsf-log-dpi nsf-detection-voip-volte
          notification";
     }
     feature i2nsf-nsf-log-vuln-scan i2nsf-nsf-log-dpi {
       description
         "This feature means it supports I2NSF nsf-log-vuln-scan nsf-log-dpi
          notification";
     }

     /*
      * Notification nodes
      */

     notification i2nsf-event {
       description
         "Notification for I2NSF Event.";
       choice sub-event-type {
         description
           "This choice must be augmented with cases for each allowed
            sub-event. Only 1 sub-event will be instantiated in each
            i2nsf-event message. Each case is expected to define one
            container with all the sub-event fields.";
         case i2nsf-system-detection-alarm {
           container i2nsf-system-detection-alarm{
             description
               "This notification is sent, when a system alarm
                is detected.";
             leaf alarm-category {
               type identityref {
                base alarm-type; system-alarm;
               }
               description
                 "The alarm category for
                  system-detection-alarm notification";
             }
             leaf component-name {
               type string;
               description
                 "The hardware component responsible for generating
                  the message. Applicable for Hardware Failure
                  Alarm.";
             }
             leaf interface-name {
               type string;
               description
                 "The interface name responsible for generating
                  the message. Applicable for Network Interface
                  Failure Alarm.";
             }
             leaf interface-state {
               type enumeration {
                 enum down {
                   description
                     "The interface state is down.";
                 }
                 enum up {
                   description
                     "The interface state is up."; up and not congested.";
                 }
                 enum congested {
                   description
                     "The interface state is up but congested.";
                 }
               }
               description
                 "The state of the interface (i.e., up, down,
                  congested). Applicable for Network Interface Failure
                  Alarm.";
             }
             uses characteristics;
             uses i2nsf-system-alarm-type-content;
             uses common-monitoring-data;
           }
         }

         case i2nsf-system-detection-event {
           container i2nsf-system-detection-event {
             description
               "This notification is sent when a security-sensitive
                authentication action fails.";
             leaf event-category {
               type identityref {
                 base event-type; system-event;
               }
               description
                 "The event category for system-detection-event";
             }
             uses characteristics;
             uses i2nsf-system-event-type-content;
             uses common-monitoring-data;
           }
         }

         case i2nsf-traffic-flows {
           container i2nsf-traffic-flows {
             description
               "This notification is sent to inform about the traffic
                flows.";
             leaf src-ip {
               type inet:ip-address;
               description
                 "The source IPv4 (or IPv6) address of the packet"; flow";
             }
             leaf dst-ip {
               type inet:ip-address;
               description
                 "The destination IPv4 (or IPv6) address of the packet"; flow";
             }
             leaf protocol {
               type identityref {
                 base protocol-type; protocol;
               }
               description
                 "The protocol type for nsf-detection-intrusion
                  notification";
             }
             leaf src-port {
               type inet:port-number;
               description
                 "The source port of the packet"; flow";
             }
             leaf dst-port {
               type inet:port-number;
               description
                 "The destination port of the packet"; flow";
             }
             leaf arrival-rate {
               type uint32;
               units "pps";
               description
                 "The average arrival rate of the packet flow in packets per second";
                  second. The average is calculated from the start of
                  the NSF service until the generation of this
                  record.";
             }
             uses characteristics;
             uses common-monitoring-data;
           }
         }

         case i2nsf-nsf-detection-session-table {
           container i2nsf-nsf-detection-session-table {
             description
               "This notification is sent, when a session table
                event is detected.";
             leaf current-session {
               type uint32;
               description
                 "The number of concurrent sessions";
             }
             leaf maximum-session {
               type uint32;
               description
                 "The maximum number of sessions that the session
                  table can support";
             }
             leaf threshold {
               type uint32;
               description
                 "The threshold triggering the event";
             }
             uses common-monitoring-data;
           }
         }
       }
     }

     notification i2nsf-log {
       description
         "Notification for I2NSF log. The notification is generated
          from the logs of the NSF.";
       choice sub-logs-type {
         description
           "This choice must be augmented with cases for each allowed
            sub-logs. Only 1 sub-event will be instantiated in each
            i2nsf-logs message. Each case is expected to define one
            container with all the sub-logs fields.";
         case i2nsf-nsf-system-access-log {
           container i2nsf-nsf-system-access-log {
             description
               "The notification is sent, if there is a new system
                log entry about a system access event.";
             leaf login-ip {
               type inet:ip-address;
               mandatory true;
               description
                 "Login IP address of a user";
             }
             leaf administrator username {
               type string;
               description
               "Administrator
                 "The login username that maintains the device";
             }
             leaf login-mode login-role {
               type login-mode; login-role;
               description
                 "Specifies the administrator user log-in mode"; role, i.e., administrator,
                  user, or guest.";
             }
             leaf operation-type {
               type operation-type;
               description
                 "The operation type that the administrator user executes";
             }
             leaf result input {
               type string;
               description
               "Command execution result";
                 "The operation performed by a user after login. The
                  operation is a command given by a user.";

             }
             leaf content output {
               type string;
               description
                 "The Operation performed by an administrator result in text format after
                login"; executing the
                  input.";
             }
             uses characteristics;
             uses common-monitoring-data;
           }
         }

         case i2nsf-system-res-util-log {
           container i2nsf-system-res-util-log {
             description
               "This notification is sent, if there is a new log
                entry representing resource utilization updates.";
             leaf system-status {
               type string; enumeration {
                 enum running {
                   description
                     "The system is active and running the security
                      service.";
                 }
                 enum waiting {
                   description
                     "The system is active but waiting for an event to
                      provide the security service.";
                 }
                 enum inactive {
                   description
                     "The system is inactive and not running the
                      security service.";
                 }
               }
               description
                 "The current systems system's running status";
             }
             leaf cpu-usage {
               type uint8;
               units "percent";
               description
                 "Specifies the relative size percentage of CPU usage with
                  respect to platform resources";
             }
             leaf memory-usage {
               type uint8;
               units "percent";
               description
                 "Specifies the size percentage of memory usage.";
             }
             list disk {
               key disk-id;
               description
                 "Disk is the hardware to store information for a
                  long period, i.e., Hard Disk or Solid-State Drive.";
               leaf disk-id {
                 type string;
                 description
                   "The ID of memory usage."; the storage disk. It is a free form
                    identifier to identify the storage disk.";
               }
               leaf disk-usage {
                 type uint8;
                 units "percent";
                 description
                   "Specifies the size percentage of disk usage";
               }
               leaf disk-left {
                 type uint8;
                 units "percent";
                 description
                   "Specifies the size percentage of disk left";
               }
             }
             leaf session-num {
               type uint8; uint32;
               description
                 "The total number of sessions";
             }
             leaf process-num {
               type uint8; uint32;
               description
                 "The total number of process"; processes";
             }
             list interface {
               key interface-id;
               description
                 "The network interface for connecting a device
                  with the network.";
               leaf interface-id {
                 type string;
                 description
                   "The ID of the network interface. It is a free form
                    identifier to identify the network interface.";
               }
               leaf in-traffic-rate {
                 type uint32;
                 units "pps";
                 description
                   "The total inbound traffic rate in pps"; packets per
                    second";
               }
               leaf out-traffic-rate {
                 type uint32;
                 units "pps";
                 description
                    "The total outbound traffic rate in pps"; packets per
                     second";
               }
               leaf in-traffic-speed {
                 type uint32;
                 units "bps";
                 description
                   "The total inbound traffic speed in bps"; bits per second";
               }
               leaf out-traffic-speed {
                 type uint32;
                 units "bps";
                 description
                   "The total outbound traffic speed in bps"; bits per
                    second";
               }
             }
             uses characteristics;
             uses common-monitoring-data;
           }
         }

         case i2nsf-system-user-activity-log {
           container i2nsf-system-user-activity-log {
             description
               "This notification is sent, if there is a new user
                activity log entry.";
             uses characteristics;
             uses i2nsf-system-event-type-content;
             uses common-monitoring-data;
             leaf access online-duration {
               type identityref {
               base access-mode;
             } uint32;
               units "seconds";
               description
                 "The access type for system-user-activity-log
                notification"; duration of a user's activeness (stays in login)
                  during a session.";

             }
             leaf online-duration logout-duration {
               type string; uint32;
               units "seconds";
               description
               "Online duration";
                 "The duration of a user's inactiveness (not in login)
                  from the last session.";
             }
             leaf logout-duration additional-info {
               type string; enumeration {
                 enum successful-login {
                   description
               "Lockout duration";
                     "The user has succeeded in login.";
                 }
           leaf additional-info
                 enum failed-login {
                   description
                     "The user has failed in login (e.g., wrong
                      password)";
                 }
                 enum logout {
                   description
                     "The user has succeeded in logout";
                 }
                 enum successful-password-changed {
                   description
                     "The password has been changed successfully";
                 }
                 enum failed-password-changed{
                   description
                     "The attempt to change password has failed";
                 }
                 enum lock {
                   description
                     "The user has been locked. A locked user cannot
                      login.";
                 }
                 enum unlock {
             type string;
                   description
                     "The user has been unlocked.";
                 }
               }
               description
                 "User activities, e.g., Successful User Login,
                  Failed Login attempts, User Logout, Successful User
                  Password Change, Failed User Password Change, User
                  Lockout, User Unlocking, and Unknown.";
             }
           }

         }
       }
     }

     notification i2nsf-nsf-event {
       description
         "Notification for I2NSF NSF Event. This notification is
          used for a specific NSF that supported such feature.";
       choice sub-event-type {
         description
         "This choice must be augmented with cases for each allowed
          sub-event. Only 1 sub-event will be instantiated in each
          i2nsf-event message. Each case is expected to define one
          container with all the sub-event fields.";
         case i2nsf-nsf-detection-ddos {
           if-feature "i2nsf-nsf-detection-ddos";
           container i2nsf-nsf-detection-ddos {
             description
               "This notification is sent, when a specific flood type
                is detected.";
           uses i2nsf-nsf-event-type-content;
             leaf attack-type {
               type identityref {
                 base flood-type; ddos-type;
               }
               description
                 "Any one of Syn flood, ACK flood, SYN-ACK flood,
                  FIN/RST flood, TCP Connection flood, UDP flood,
                  ICMP (i.e., ICMPv4 or ICMPv6) flood, HTTP flood,
                  HTTPS flood, DNS query flood, DNS reply flood, SIP
                  flood, etc.";
             }
             leaf start-time {
               type yang:date-and-time;
               mandatory true;
               description
                 "The time stamp indicating when the attack started";
             }
             leaf end-time {
               type yang:date-and-time;
               mandatory true;
               description
                 "The time stamp indicating when the attack ended";
             }
           leaf
             leaf-list attack-src-ip {
               type inet:ip-address;
               description
                 "The source IPv4 (or IPv6) addresses of attack
                  traffic. If there are a large number of It can hold multiple IPv4 (or IPv6) addresses, then pick a certain number
                of resources according to different rules.";
                  addresses.";
             }
           leaf
             leaf-list attack-dst-ip {
               type inet:ip-address; inet:ip-prefix;
               description
                 "The destination IPv4 (or IPv6) addresses of attack
                  traffic. If there are a large number of It can hold multiple IPv4 (or IPv6) addresses, then pick a certain number
                  addresses.";
             }
             leaf-list attack-src-port {
               type inet:port-number;
               description
                 "The source ports of resources according to different rules."; the DDoS attack";
             }
             leaf-list attack-dst-port {
               type inet:port-number;
               description
                 "The destination ports of the DDoS attack";
             }
             leaf rule-name {
               type leafref {
                 path
                   "/nsfi:i2nsf-security-policy"
                  +"/nsfi:rules/nsfi:rule-name";
               }
               mandatory true;
               description
                 "The name of the I2NSF Policy Rule being triggered";
             }
             leaf raw-info {
               type string;
               description
                 "The information describing the packet
                  triggering the event.";
             }
             uses attack-rates;
             uses log-action;
             uses characteristics;
             uses common-monitoring-data;
           }
         }
         case i2nsf-nsf-detection-virus {
           if-feature "i2nsf-nsf-detection-virus";
           container i2nsf-nsf-detection-virus {
             description
               "This notification is sent, when a virus is detected.";
             uses i2nsf-nsf-event-type-content-extend;
             leaf virus {
               type identityref {
                 base virus-type;
               }
               description
                 "The virus type for nsf-detection-virus notification";
             }
             leaf virus-name {
               type string;
               description
                 "The name of the detected virus";
             }
             leaf file-type {
               type string;
               description
                 "The type of file virus code is found in (if
                  applicable).";
               reference
                 "IANA Website: Media Types";
             }
             leaf file-name {
               type string;
               description
                 "The name of file virus code is found in (if
                  applicable).";
             }
             leaf os {
               type string;
               description
               "Simple OS information";
                 "The operating system of the device.";
             }
             uses log-action;
             uses characteristics;
             uses common-monitoring-data;
           }
         }
         case i2nsf-nsf-detection-intrusion {
           if-feature "i2nsf-nsf-detection-intrusion";
           container i2nsf-nsf-detection-intrusion {
             description
               "This notification is sent, when an intrusion event
                is detected.";
             uses i2nsf-nsf-event-type-content-extend;
             leaf protocol {
               type identityref {
                 base protocol-type; transport-protocol;
               }
               description
                 "The transport protocol type for
                  nsf-detection-intrusion notification";
             }
             leaf app {
               type string; identityref {
                 base application-protocol;
               }
               description
                 "The employed application layer protocol";
             }
             leaf attack-type {
               type identityref {
                 base intrusion-attack-type;
               }
               description
                 "The sub attack type for intrusion attack";
             }
             uses log-action;
             uses attack-rates;
             uses characteristics;
             uses common-monitoring-data;
           }
         }
         case i2nsf-nsf-detection-botnet {
         if-feature "i2nsf-nsf-detection-botnet";
         container i2nsf-nsf-detection-botnet {
           description
             "This notification is sent, when a botnet event is
              detected.";
           uses i2nsf-nsf-event-type-content-extend;
           leaf attack-type {
             type identityref {
               base botnet-attack-type;
             }
            description
               "The attack type for botnet attack";
           }
           leaf protocol {
             type identityref {
               base protocol-type;
             }
             description
               "The protocol type for nsf-detection-botnet
                notification";
           }
           leaf botnet-name {
             type string;
             description
               "The name of the detected botnet";
           }
           leaf role {
             type string;
             description
               "The role of the communicating
                parties within the botnet";
           }
           uses log-action;
           leaf botnet-pkt-num{
             type uint8;
             description
               "The number of the packets sent to or from the detected
                botnet";
           }
           leaf os{
             type string;
             description
               "Simple OS information";
           }
           uses characteristics;
           uses common-monitoring-data;
         }
       }
       case i2nsf-nsf-detection-web-attack {
           if-feature "i2nsf-nsf-detection-web-attack";
           container i2nsf-nsf-detection-web-attack {
             description
               "This notification is sent, when an attack event is
                detected.";
             uses i2nsf-nsf-event-type-content-extend;
             leaf attack-type {
               type identityref {
                 base web-attack-type;
               }
               description
                 "Concrete web attack type, e.g., SQL injection,
                  command injection, XSS, and CSRF.";
             }
             leaf request-method {
               type identityref {
                 base req-method; request-method;
               }
               description
                 "The method of requirement. For instance, HTTP request method, e.g., PUT or
                GET in HTTP.";

           }
           leaf req-uri {
             type string;
             description
               "Requested URI";
           }
           leaf uri-category {
             type string;
             description
               "Matched URI category";
           }
           leaf-list filtering-type {
             type identityref {
               base filter-type;
             }
             description
               "URL filtering type, e.g., Blacklist, Whitelist,
                User-Defined, Predefined, Malicious Category, GET.";
               reference
                 "RFC 7231: Hypertext Transfer Protocol (HTTP/1.1):
                  Semantics and Unknown";
           }
           leaf rsp-code {
             type string;
             description
               "Response code";
           }
           leaf req-clientapp {
             type string;
             description
               "The client application";
           }
           leaf req-cookies {
             type string;
             description
               "Cookies"; Content - Request Methods";
             }
             leaf req-host req-uri {
               type string;
               description
                 "The domain name of the requested host";
           }
           uses characteristics;
           uses log-action;
           uses common-monitoring-data;
         }
       }
       case i2nsf-nsf-log-vuln-scan {
         if-feature "i2nsf-nsf-log-vuln-scan";
         container i2nsf-nsf-log-vuln-scan {
           description
             "This notification is sent, if there is a new
              vulnerability-scan report in the NSF log.";
           leaf vulnerability-id {
             type uint8;
             description
               "The vulnerability ID";
           }
           leaf victim-ip {
             type inet:ip-address;
             description
               "IPv4 (or IPv6) address of the victim host which
                has vulnerabilities"; Requested URI";
             }
           leaf protocol
             leaf-list filtering-type {
               type identityref {
                 base protocol-type; filter-type;
               }
               description
               "The protocol type for nsf-log-vuln-scan
                notification";
                 "URL filtering type, e.g., deny-list, allow-list,
                  and Unknown";
             }
             leaf port-num req-user-agent {
               type inet:port-number; string;
               description
                 "The port number"; request user agent";
             }
             leaf level req-cookie {
               type severity; string;
               description
                 "The vulnerability severity"; HTTP Cookie previously sent by the server with
                  Set-Cookie";
             }
             leaf os req-host {
               type string;
               description
               "simple OS information";
                 "The domain name of the requested host";
             }
             leaf vulnerability-info response-code {
               type string;
               description
                 "The information about HTTP Response code";
               reference
                 "IANA Website: Hypertext Transfer Protocol (HTTP)
                  Status Code Registry";
             }
             uses characteristics;
             uses log-action;
             uses common-monitoring-data;
           }
         }
         case i2nsf-nsf-detection-voip-volte{
           if-feature "i2nsf-nsf-detection-voip-volte";
           container i2nsf-nsf-detection-voip-volte {
             description
               "This notification is sent, when a VoIP/VoLTE violation
                is detected.";
             uses i2nsf-nsf-event-type-content-extend;
             leaf-list source-voice-id {
               type string;
               description
                 "The detected source voice ID for VoIP and VoLTE that
                  violates the vulnerability"; security policy.";
             }
           leaf fix-suggestion
             leaf-list destination-voice-id {
               type string;
               description
                 "The fix suggestion to detected destination voice ID for VoIP and VoLTE
                  that violates the vulnerability"; security policy.";
             }
           leaf service
             leaf-list user-agent {
               type string;
               description
                 "The service which has vulnerability in detected user-agent for VoIP and VoLTE that violates
                  the victim
                host"; security policy.";
             }
           uses characteristics;
           uses common-monitoring-data;
           }
         }
         case i2nsf-nsf-log-dpi {
           if-feature "i2nsf-nsf-log-dpi";
           container i2nsf-nsf-log-dpi {
             description
               "This notification is sent, if there is a new DPI
                event in the NSF log.";
             leaf attack-type {
               type dpi-type;
               description
                 "The type of the DPI";
             }
             uses characteristics;
             uses i2nsf-nsf-counters-type-content;
             uses common-monitoring-data;
           }
         }
       }
     }
     /*
      * Data nodes
      */
     container i2nsf-counters {
       config false;
       description
         "This is probably better covered by an import as this
          will not be notifications.  Counters are not very
          suitable as telemetry, maybe via periodic
          subscriptions, which would still violate the principle
          of least surprise.";
       list system-interface {
         key interface-name;
         description
           "Interface counters provide the visibility of traffic into
            and out of an NSF, and bandwidth usage.";
         uses characteristics;
         uses i2nsf-system-counter-type-content;
         uses common-monitoring-data;
         uses timestamp;
       }
       list nsf-firewall {
         key policy-name;
         description
           "Firewall counters provide the visibility of traffic
            signatures, bandwidth usage, and how the configured security
            and bandwidth policies have been applied.";
         uses characteristics;
         uses i2nsf-nsf-counters-type-content;
         uses traffic-rates;
         uses common-monitoring-data;
         uses timestamp;
       }
       list nsf-policy-hits {
         key policy-name;
         description
           "Policy Hit Counters record the number of hits that traffic
            packets match a security policy. It can check if policy
            configurations are correct or not.";
         uses characteristics;
         uses i2nsf-nsf-counters-type-content;
         uses common-monitoring-data;
         leaf hit-times {
           type yang:counter32;
           description
             "The number of times a policy is hit";
         }
         uses timestamp;
       }
     }

     container i2nsf-monitoring-configuration {
       description
         "The container for configuring I2NSF monitoring.";
       container i2nsf-system-detection-alarm {
         description
           "The container for configuring I2NSF system-detection-alarm
            notification";

         uses enable-notification;
         list system-alarm {
           key alarm-type;
           description
             "Configuration for system alarm (i.e., CPU, Memory,
              and Disk Usage)";
           leaf alarm-type {
             type enumeration {
               enum CPU {
                 description
                   "To configure the CPU usage threshold to trigger the
                    CPU-USAGE-ALARM";
               }
               enum Memory {
                 description
                   "To configure the Memory usage threshold to trigger
                    the MEM-USAGE-ALARM";
               }
               enum Disk {
                 description
                   "To configure the Disk (storage) usage threshold to
                    trigger the DISK-USAGE-ALARM";
               }
             }
             description
               "Type of alarm to be configured";
           }
           leaf threshold {
             type uint8 {
               range "1..100";
             }
             units "percent";
             description
               "The configuration for threshold percentage to trigger
                the alarm. The alarm will be triggered if the usage
                is exceeded the threshold.";
           }
           uses dampening;
         }
       }
       container i2nsf-system-detection-event {
         description
           "The container for configuring I2NSF system-detection-event
            notification";
         uses enable-notification;
         uses dampening;
       }
       container i2nsf-traffic-flows {
         description
           "The container for configuring I2NSF traffic-flows
            notification";
         uses dampening;
         uses enable-notification;
       }
       container i2nsf-nsf-detection-ddos {
         if-feature "i2nsf-nsf-detection-ddos";
         description
           "The container for configuring I2NSF nsf-detection-ddos
            notification";
         uses enable-notification;
         uses dampening;
       }
       container i2nsf-nsf-detection-session-table-configuration {
         description
           "The container for configuring I2NSF nsf-detection-session-
            table notification";
         uses enable-notification;
         uses dampening;
       }
       container i2nsf-nsf-detection-virus {
       if-feature "i2nsf-nsf-detection-virus";
       description
         "The container for configuring I2NSF nsf-detection-virus
          notification";
       uses enable-notification;
       uses dampening;
     }
     container i2nsf-nsf-detection-intrusion {
         if-feature "i2nsf-nsf-detection-intrusion";
         description
           "The container for configuring I2NSF nsf-detection-intrusion
            notification";
         uses enable-notification;
         uses dampening;
       }
       container i2nsf-nsf-detection-botnet {
       if-feature "i2nsf-nsf-detection-botnet";
       description
         "The container for configuring I2NSF nsf-detection-botnet
          notification";
       uses enable-notification;
       uses dampening;
     }
     container i2nsf-nsf-detection-web-attack {
         if-feature "i2nsf-nsf-detection-web-attack";
         description
           "The container for configuring I2NSF nsf-detection-web-attack
            notification";
         uses enable-notification;
         uses dampening;
       }
       container i2nsf-nsf-system-access-log {
         description
           "The container for configuring I2NSF system-access-log
            notification";
         uses enable-notification;
         uses dampening;
       }
       container i2nsf-system-res-util-log {
         description
           "The container for configuring I2NSF system-res-util-log
            notification";

         uses enable-notification;
         uses dampening;
       }
       container i2nsf-system-user-activity-log {
         description
           "The container for configuring I2NSF system-user-activity-log
            notification";
         uses enable-notification;
         uses dampening;
       }
       container i2nsf-nsf-log-dpi {
         if-feature "i2nsf-nsf-log-dpi";
         description
           "The container for configuring I2NSF nsf-log-dpi
            notification";
         uses enable-notification;
         uses dampening;
       }
       container i2nsf-nsf-log-vuln-scan {
       if-feature "i2nsf-nsf-log-vuln-scan";
       description
         "The container for configuring I2NSF nsf-log-vuln-scan
          notification";
       uses enable-notification;
       uses dampening;
     }
     container i2nsf-counter {
         description
           "This is used to configure the counters
            for monitoring an NSF";
         leaf period {
           type uint16;
           units "minutes";
           default 0;
           description
             "The configuration for the period interval of reporting
              the counter. If 0, then the counter period is disabled.
              If value is not 0, then the counter will be reported
              following the period value.";
         }
       }
     }
   }
   <CODE ENDS>

                     Figure 2: Data Model of Monitoring

11.

10.  I2NSF Event Stream

   This section discusses the NETCONF event stream for I2NSF NSF
   Monitoring subscription.  The YANG module in this document supports
   "ietf-subscribed-notifications" YANG module [RFC8639] for
   subscription.  The reserved event stream name for this document is
   "I2NSF-Monitoring".  The NETCONF Server (e.g., an NSF) MUST support
   "I2NSF-Monitoring" event stream for an NSF data collector (e.g.,
   Security Controller and NSF data analyzer). Controller).  The "I2NSF-Monitoring" event stream contains
   all I2NSF events described in this document.  The following example
   shows the capabilities of the event streams of an NSF (e.g.,
   "NETCONF" and "I2NSF-Monitoring" event streams) by the subscription
   of an NSF data collector; note that this example XML file is
   delivered by an NSF to an NSF data collector:

   <?xml version="1.0" encoding="UTF-8"?>
   <rpc-reply message-id="1"
              xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
     <data>
       <netconf xmlns="urn:ietf:params:xml:ns:netmod:notification">
         <streams>
           <stream>
             <name>NETCONF</name>
             <description>Default NETCONF Event Stream</description>
             <replaySupport>false</replaySupport>
           </stream>
           <stream>
             <name>I2NSF-Monitoring</name>
             <description>I2NSF Monitoring Event Stream</description>
             <replaySupport>true</replaySupport>
             <replayLogCreationTime>
               2021-04-29T09:37:39+00:00
             </replayLogCreationTime>
           </stream>
         </streams>
       </netconf>
     </data>
   </rpc-reply>

      Figure 3: Example of NETCONF Server supporting I2NSF-Monitoring
                                Event Stream

12.

11.  XML Examples for I2NSF NSF Monitoring

   This section shows the XML examples of I2NSF NSF Monitoring data
   delivered via Monitoring Interface from an NSF.

12.1.

11.1.  I2NSF System Detection Alarm

   The following example shows an alarm triggered by Memory Usage of the
   server; note that this example XML file is delivered by an NSF to an
   NSF data collector:

   <?xml version="1.0" encoding="UTF-8"?>
   <notification
    xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
     <eventTime>2021-04-29T07:43:52.181088+00:00</eventTime>
     <i2nsf-event
       xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring">
       <i2nsf-system-detection-alarm>
         <alarm-category
           xmlns:nsfmi="urn:ietf:params:xml:ns:yang:\
                      ietf-i2nsf-nsf-monitoring">
          nsfmi:mem-usage-alarm
           nsfmi:memory-alarm
         </alarm-category>
         <acquisition-method
           xmlns:nsfmi="urn:ietf:params:xml:ns:yang:\
                        ietf-i2nsf-nsf-monitoring">
           nsfmi:subscription
         </acquisition-method>
         <emission-type
           xmlns:nsfmi="urn:ietf:params:xml:ns:yang:\
                        ietf-i2nsf-nsf-monitoring">
           nsfmi:on-change
         </emission-type>
         <dampening-type
           xmlns:nsfmi="urn:ietf:params:xml:ns:yang:\
                        ietf-i2nsf-nsf-monitoring">
           nsfmi:on-repetition
         </dampening-type>
         <usage>91</usage>
         <threshold>90</threshold>
         <message>Memory Usage Exceeded the Threshold</message>
         <nsf-name>time_based_firewall</nsf-name>
         <severity>high</severity>
       </i2nsf-system-detection-alarm>
     </i2nsf-event>
   </notification>

       Figure 4: Example of I2NSF System Detection Alarm triggered by
                                Memory Usage

   The XML data above shows:

   1.  The NSF that sends the information is named
       "time_based_firewall".

   2.  The memory usage of the NSF triggered the alarm.

   3.  The monitoring information is received by subscription method.

   4.  The monitoring information is emitted "on-change".

   5.  The monitoring information is dampened "on-repetition".

   6.  The memory usage of the NSF is 91 percent.

   7.  The memory threshold to trigger the alarm is 90 percent.

   8.  The severity level of the notification is high.

12.2.

11.2.  I2NSF Interface Counters

   To get the I2NSF system interface counters information by query,
   NETCONF Client (e.g., NSF data collector) needs to initiate GET
   connection with NETCONF Server (e.g., NSF).  The following XML file
   can be used to get the state data and filter the information.

   <?xml version="1.0" encoding="UTF-8"?>
   <rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="1">
     <get>
       <filter
         xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring">
         <i2nsf-counters>
           <system-interface/>
         </i2nsf-counters>
       </filter>
     </get>
   </rpc>

     Figure 5: XML Example for NETCONF GET with System Interface Filter

   The following XML file shows the reply from the NETCONF Server (e.g.,
   NSF):

   <?xml version="1.0" encoding="UTF-8"?>
   <rpc-reply message-id="1"
              xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
     <data>
       <i2nsf-counters
         xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring">
         <system-interface>
           <interface-name>ens3</interface-name>
           <acquisition-method
             xmlns:nsfmi="urn:ietf:params:xml:ns:yang:\
                          ietf-i2nsf-nsf-monitoring">
             nsfmi:query
           </acquisition-method>
           <in-total-traffic-bytes>549050</in-total-traffic-bytes>
           <out-total-traffic-bytes>814956</out-total-traffic-bytes>
           <in-drop-traffic-bytes>0</in-drop-traffic-bytes>
           <out-drop-traffic-bytes>5078</out-drop-traffic-bytes>
           <nsf-name>time_based_firewall</nsf-name>
         </system-interface>
         <system-interface>
           <interface-name>lo</interface-name>
           <acquisition-method
             xmlns:nsfmi="urn:ietf:params:xml:ns:yang:\
                          ietf-i2nsf-nsf-monitoring">
             nsfmi:query
           </acquisition-method>
           <in-total-traffic-bytes>48487</in-total-traffic-bytes>
           <out-total-traffic-bytes>48487</out-total-traffic-bytes>
           <in-drop-traffic-bytes>0</in-drop-traffic-bytes>
           <out-drop-traffic-bytes>0</out-drop-traffic-bytes>
           <nsf-name>time_based_firewall</nsf-name>
         </system-interface>
       </i2nsf-counters>
     </data>
   </rpc-reply>

    Figure 6: Example of I2NSF System Interface Counters XML Information

13.

12.  IANA Considerations

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

     URI: urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring
     Registrant Contact: The IESG.
     XML: N/A; the requested URI is an XML namespace.

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

     name: ietf-i2nsf-nsf-monitoring
     namespace: urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring
     prefix: nsfmi
     reference: RFC XXXX

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

14.

13.  Security Considerations

   The

   YANG module described in this document defines a schema for data that
   is designed to be accessed via network management protocols such as
   NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer is
   the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].

   The NETCONF access control model [RFC8341] provides the means to
   restrict access for particular NETCONF or RESTCONF users to a
   preconfigured subset of all available NETCONF or RESTCONF protocol
   operations and content.

   All data nodes defined in the YANG module which can be created,
   modified and deleted (i.e., config true, which is the default) are
   considered sensitive. sensitive as they all could potentially impact security
   monitoring and mitigation activities.  Write operations (e.g., edit-config) edit-
   config) applied to these data nodes without proper protection can negatively affect
   framework operations.  The monitoring YANG module should could
   result in missed alarms or incorrect alarms information being
   returned to the NSF data collector.  There are threats that need to
   be protected
   by considered and mitigated:

   Compromised NSF with valid credentials:  It can send falsified
      information to the secure communication channel, NSF data collector to ensure its confidentiality mislead detection or
      mitigation activities; and/or to hide activity.  Currently, there
      is no in-framework mechanism to mitigate this and integrity.  In another side, an issue for all
      monitoring infrastructures.  It is important to keep the enclosure
      of confidential information to unauthorized persons to mitigate
      the possibility of compromising the NSF and with this information.

   Compromised NSF data collector can with valid credentials:  It has
      visibility to all collected security alarms; entire detection and
      mitigation infrastructure may be faked, which lead suspect.  It is important to undesirable results (i.e., leakage keep
      the enclosure of an
   NSF's important operational information, and faked confidential information to unauthorized persons
      to mitigate the possibility of compromising the NSF sending with this
      information.

   Impersonating NSF:  It is a system trying to send false information
      while imitating an NSF; client authentication would help the NSF
      data collector to mislead identify this invalid NSF in the "push" model
      (NSF-to-collector), while the "pull" model (collector-to-NSF)
      should already be addressed with the authentication.

   Impersonating NSF data collector).  The mutual
   authentication collector:  It is a rogue NSF data collector
      with which a legitimate NSF is essential tricked into communicating; for
      "push" model (NSF-to-collector), it is important to protected against this kind of attack.
   The current mainstream security technologies (i.e., TLS, DTLS, IPsec,
   and X.509 PKI) can have valid
      credentials, without it it should not work; for "pull" model
      (collector-to-NSF), mutual authentication should be employed appropriately used to provide
      mitigate the above
   security functions. threat.

   In addition, to defend against the DDoS attack caused by a lot of
   NSFs sending massive notifications to the NSF data collector, the
   rate limiting or similar mechanisms should be considered in both an
   NSF and NSF data collector, whether in advance or just in the process
   of DDoS attack.

15.

   All of the readable data nodes in this YANG module may be considered
   vulnerable in some network environments.  Some data also may contain
   private information that is highly sensitive to the user, such as the
   IP address of a user in the container "i2nsf-system-user-activity-
   log" and the container "i2nsf-system-detection-event".  It is
   important to control read access (e.g., via get, get-config, or
   notification) to the data nodes.  If access control is not properly
   configured, it can expose system internals to those who should not
   have access to this information.

14.  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 (2020-0-00395, Standard Development of Blockchain based
   Network Management Automation Technology).  This work was supported
   in part by the MSIT under the Information Technology Research Center
   (ITRC) support program (IITP-2021-2017-0-01633) supervised by the
   IITP.

16.

15.  Contributors

   This document is made by the group effort of I2NSF working group.
   Many people actively contributed to this document.  The authors
   sincerely appreciate their contributions.

   The following are co-authors of this document:

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

   Jinyong (Tim) Kim Department of Electronic, Electrical and Computer
   Engineering Sungkyunkwan University 2066 Seo-ro Jangan-gu Suwon,
   Gyeonggi-do 16419 Republic of Korea EMail: timkim@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

   Dacheng Zhang Huawei EMail: dacheng.zhang@huawei.com

   Yi Wu Aliababa Group EMail: anren.wy@alibaba-inc.com

   Rakesh Kumar Juniper Networks 1133 Innovation Way Sunnyvale, CA 94089
   USA EMail: rkkumar@juniper.net

   Anil Lohiya Juniper Networks EMail: alohiya@juniper.net

17.

16.  References

17.1.

16.1.  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>.

   [RFC0793]  Postel, J., "Transmission Control Protocol", STD 7,
              RFC 793, DOI 10.17487/RFC0793, September 1981,
              <https://www.rfc-editor.org/info/rfc793>.

   [RFC0956]  Mills, D., "Algorithms for synchronizing network clocks",
              RFC 956, DOI 10.17487/RFC0956, September 1985,
              <https://www.rfc-editor.org/info/rfc956>.

   [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>.

   [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>.

   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
              Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
              Transfer Protocol -- HTTP/1.1", RFC 2616,
              DOI 10.17487/RFC2616, June 1999,
              <https://www.rfc-editor.org/info/rfc2616>.

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

   [RFC3877]  Chisholm, S. and D. Romascanu, "Alarm Management
              Information Base (MIB)", RFC 3877, DOI 10.17487/RFC3877,
              September 2004, <https://www.rfc-editor.org/info/rfc3877>.

   [RFC3954]  Claise, B., Ed., "Cisco Systems NetFlow Services Export
              Version 9", RFC 3954, DOI 10.17487/RFC3954, October 2004,
              <https://www.rfc-editor.org/info/rfc3954>.

   [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>.

   [RFC4949]  Shirey, R., "Internet Security Glossary, Version 2",
              FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
              <https://www.rfc-editor.org/info/rfc4949>.

   [RFC5424]  Gerhards, R., "The Syslog Protocol",

   [RFC5277]  Chisholm, S. and H. Trevino, "NETCONF Event
              Notifications", RFC 5424, 5277, DOI 10.17487/RFC5424, March 2009,
              <https://www.rfc-editor.org/info/rfc5424>. 10.17487/RFC5277, July 2008,
              <https://www.rfc-editor.org/info/rfc5277>.

   [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>.

   [RFC6587]  Gerhards, R. and C. Lonvick, "Transmission of Syslog
              Messages over TCP", RFC 6587, 6242, DOI 10.17487/RFC6587, April
              2012, <https://www.rfc-editor.org/info/rfc6587>. 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

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

   [RFC7011]  Claise, B., Ed., Trammell, B., Ed., and P. Aitken,
              "Specification of the IP Flow Information Export (IPFIX)
              Protocol for the Exchange of Flow Information", STD 77,
              RFC 7011, DOI 10.17487/RFC7011, September 2013,
              <https://www.rfc-editor.org/info/rfc7011>.

   [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>.

   [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>.

   [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>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [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>.

   [RFC8632]  Vallin, S. and M. Bjorklund, "A YANG Data Model for Alarm
              Management", RFC 8632, DOI 10.17487/RFC8632, September
              2019, <https://www.rfc-editor.org/info/rfc8632>.

   [RFC8639]  Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
              E., and A. Tripathy, "Subscription to YANG Notifications",
              RFC 8639, DOI 10.17487/RFC8639, September 2019,
              <https://www.rfc-editor.org/info/rfc8639>.

   [RFC8641]  Clemm, A. and E. Voit, "Subscription to YANG Notifications
              for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641,
              September 2019, <https://www.rfc-editor.org/info/rfc8641>.

17.2.

16.2.  Informative References

   [I-D.ietf-i2nsf-applicability]
              Jeong, J., Hyun, S., Ahn, T., Hares, S., and D. Lopez,
              "Applicability of Interfaces to Network Security Functions
              to Network-Based

   [RFC4949]  Shirey, R., "Internet Security Services", draft-ietf-i2nsf-
              applicability-18 (work in progress), September 2019.

   [I-D.ietf-i2nsf-capability]
              Xia, Glossary, Version 2",
              FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
              <https://www.rfc-editor.org/info/rfc4949>.

   [RFC8329]  Lopez, D., Lopez, E., Dunbar, L., Strassner, J., Basile, C., and D. Lopez,
              "Information Model of NSFs Capabilities", draft-ietf-
              i2nsf-capability-05 (work in progress), April 2019. R.
              Kumar, "Framework for Interface to Network Security
              Functions", RFC 8329, DOI 10.17487/RFC8329, February 2018,
              <https://www.rfc-editor.org/info/rfc8329>.

   [I-D.ietf-i2nsf-consumer-facing-interface-dm]
              Jeong, J., J. (., Chung, C., Ahn, T., Kumar, R., and S. Hares,
              "I2NSF Consumer-Facing Interface YANG Data Model", draft-
              ietf-i2nsf-consumer-facing-interface-dm-13 (work Work in
              progress),
              Progress, Internet-Draft, draft-ietf-i2nsf-consumer-
              facing-interface-dm-13, 8 March 2021. 2021,
              <https://www.ietf.org/archive/id/draft-ietf-i2nsf-
              consumer-facing-interface-dm-13.txt>.

   [I-D.ietf-i2nsf-nsf-facing-interface-dm]
              Kim, J., J. (., Jeong, J. (., Park, J., J., J., PARK, P., Hares, S., and Q. Lin,
              "I2NSF Network Security Function-Facing Interface YANG
              Data Model", draft-ietf-i2nsf-nsf-facing-interface-
              dm-12 (work Work in progress), Progress, Internet-Draft, draft-ietf-
              i2nsf-nsf-facing-interface-dm-12, 8 March 2021. 2021,
              <https://www.ietf.org/archive/id/draft-ietf-i2nsf-nsf-
              facing-interface-dm-12.txt>.

   [I-D.ietf-i2nsf-registration-interface-dm]
              Hyun, S., Jeong, J., J. P., Roh, T., Wi, S., J., J., and P. PARK, J. Park,
              "I2NSF Registration Interface YANG Data Model", draft-
              ietf-i2nsf-registration-interface-dm-10 (work Work in
              progress),
              Progress, Internet-Draft, draft-ietf-i2nsf-registration-
              interface-dm-10, 21 February 2021.

   [I-D.ietf-netconf-subscribed-notifications]
              Voit, E., Clemm, A., Prieto, A., Nilsen-Nygaard, E., 2021,
              <https://www.ietf.org/archive/id/draft-ietf-i2nsf-
              registration-interface-dm-10.txt>.

   [I-D.ietf-i2nsf-applicability]
              Jeong, J. P., Hyun, S., Ahn, T., Hares, S., and
              A. Tripathy, "Subscription D. R.
              Lopez, "Applicability of Interfaces to YANG Event Notifications",
              draft-ietf-netconf-subscribed-notifications-26 (work in
              progress), May 2019.

   [I-D.ietf-netconf-yang-push]
              Clemm, A. and E. Voit, "Subscription Network Security
              Functions to YANG Datastores",
              draft-ietf-netconf-yang-push-25 (work Network-Based Security Services", Work in progress), May
              2019.
              Progress, Internet-Draft, draft-ietf-i2nsf-applicability-
              18, 16 September 2019, <https://www.ietf.org/archive/id/
              draft-ietf-i2nsf-applicability-18.txt>.

   [I-D.yang-i2nsf-security-policy-translation]
              Jeong, J., J. (., Lingga, P., Yang, J., and C. Chung,
              "Security Policy Translation in Interface to Network
              Security Functions", draft-yang-i2nsf-security-policy-
              translation-08 (work Work in progress), Progress, Internet-Draft,
              draft-yang-i2nsf-security-policy-translation-08, 22
              February 2021. 2021, <https://www.ietf.org/archive/id/draft-
              yang-i2nsf-security-policy-translation-08.txt>.

   [IANA-HTTP-Status-Code]
              Internet Assigned Numbers Authority (IANA), "Hypertext
              Transfer Protocol (HTTP) Status Code Registry", September
              2018, <https://www.iana.org/assignments/http-status-codes/
              http-status-codes.xhtml>.

   [IANA-Media-Types]
              Internet Assigned Numbers Authority (IANA), "Media Types",
              August 2021, <https://www.iana.org/assignments/media-
              types/media-types.xhtml>.

Appendix A.  Changes from draft-ietf-i2nsf-nsf-monitoring-data-model-07 draft-ietf-i2nsf-nsf-monitoring-data-model-08

   The following changes are made from draft-ietf-i2nsf-nsf-monitoring-
   data-model-07:

   o
   data-model-08:

   *  This version is revised according to the comments from both following Tom
      Petch and Andy Bierman. Petch's, Martin Bjorklund's,
      and Roman Danyliw's Comments.

   *  This version is revised to synchronize with other I2NSF documents.

Authors' Addresses

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

   Phone: +82 31 299 4957
   Fax:   +82 31 290 7996
   EMail:
   Email: pauljeong@skku.edu
   URI:   http://iotlab.skku.edu/people-jaehoon-jeong.php

   Patrick Lingga
   Department of Electronic, Electrical and Computer Engineering
   Sungkyunkwan University
   2066 Seobu-Ro, Jangan-Gu
   Suwon,
   Suwon
   Gyeonggi-Do
   16419
   Republic of Korea

   Phone: +82 31 299 4957
   EMail:
   Email: patricklink@skku.edu
   Susan Hares
   Huawei
   7453 Hickory Hill
   Saline, MI 48176
   USA
   United States of America

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

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

   EMail:

   Email: Frank.xialiang@huawei.com

   Henk Birkholz
   Fraunhofer Institute for Secure Information Technology
   Rheinstrasse 75
   Darmstadt
   64295 Darmstadt
   Germany

   EMail:

   Email: henk.birkholz@sit.fraunhofer.de