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<rfc category="std" docName="draft-pedro-ite-01" ipr="trust200902" consensus="true" submissionType="IETF">

  <front>

    <title abbrev="Intent Translation Engine">Intent Translation Engine for Intent-Based Networking</title>

    <author fullname="Pedro Martinez-Julia" initials="P." role="editor" surname="Martinez-Julia">
      <organization>NICT</organization>
      <address>
        <postal>
          <street>4-2-1, Nukui-Kitamachi, Koganei</street>
          <region>Tokyo</region>
          <code>184-8795</code>
          <country>Japan</country>
        </postal>
        <phone>+81 42 327 7293</phone>
        <email>pedro@nict.go.jp</email>
      </address>
    </author>

    <author fullname="Jaehoon Paul Jeong" initials="J." role="editor" surname="Jeong">
        <organization abbrev="Sungkyunkwan University">
        Department of Computer Science and Engineering
        </organization>
        <address>
            <postal>
                <street>Sungkyunkwan University</street>
                <street>2066 Seobu-Ro, Jangan-Gu</street>
                <city>Suwon</city> <region>Gyeonggi-Do</region>
                <code>16419</code>
                <country>Republic of Korea</country>
            </postal>
            <phone>+82 31 299 4957</phone>
            <facsimile>+82 31 290 7996</facsimile>
            <email>pauljeong@skku.edu</email>
            <uri>http://iotlab.skku.edu/people-jaehoon-jeong.php
         </uri>
        </address>
    </author>

    <date year="2024" month="March" day="5"/>

    <area>Internet-Draft</area>

    <workgroup>Network Management Research Group</workgroup>

    <keyword>network</keyword>
    <keyword>intent</keyword>
    <keyword>translation</keyword>
    <keyword>translator</keyword>
    <keyword>engine</keyword>
    <keyword>policy</keyword>
    <keyword>management</keyword>

    <abstract>
      <t>This document specifies the schemas and models required to realize
      the data formats and interfaces for Intent-Based Networking (IBN).
      They are needed to enable the composition of services to build a
      translation engine for IBN-based network management.
      This intent translation engine (called an intent translator) is an
      essential function for network intents to be enforced into a target
      network for the configuration and management of the network and its
      security.</t>
    </abstract>

  </front>

  <middle>

    <section title="Introduction">
      <t>The increased difficulty to define management goals and policies enforced to networks and security
       has raised the definition of Intent-Based Networking (IBN). It abstracts the definition of those goals and policies in the form of network intents.</t>
       <t>
       An intent is a declarative statement to request a configuration or management for a network or security function <xref target="TS-28.312" /><xref target="TR-28.812" />. It addresses more on "What" is needed (i.e., declarative statement) to be fulfilled than "How" it should be fulfilled (i.e., imperative statement).</t>
      <t>For IBN to be properly realized, it is envisioned that many stakeholders would be involved in the translation of network intents to particular policies and configurations. Thus, there will be many components and services that would be composed to construct a solution to implement network intents.</t>
      <t>This document specifies the schemas and models required to realize the data formats and interfaces 
      for IBN-based network management. They are needed to enable the composition of services to build a translation engine for network intents, namely Intent Translation Engine (or Intent Translator).</t>
    </section>

    <section title="Terminology">
      <t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in <xref target="RFC2119">RFC 2119</xref>.</t>
    </section>

    <section title="Intent Translation Engine">
      <t>This document specifes the required data formats and interfaces that MUST be implmeented by the components of an Intent Translation Engine (ITE), that is, an Intent Translator. Therefore, this extends
      the Intent Classification in <xref target="RFC9316" /> and drives the implementation of the specifications REQUIRED to propertly classify network intents.</t>
      <section title="Iteraction Between the ITE and Network Tentants">
        <t>The data formats required for enabling interaction between the ITE and network tenants are as follows:
          <list style="symbols">
              <t>[TF1] Schema---Resource Description Framework (RDF) ontology and YANG model---that must be used to format intents introduced in the ITE.</t>
              <t>[TF2] Schema---RDF ontology and YANG model---that must be used to format declarations of intent semantics---namely, the set of concepts, relations, and ontologies that can be present in an intent.</t>
          </list>
        </t>
        <t>The intefaces required for enabling interaction between the ITE and network tenants are as follows:
          <list style="symbols">
            <t>[TI1] Schema---RDF ontology and YANG model---that must be used by a tenant or other external entity to format and transmit an intent to the ITE.</t>
            <t>[TI2] Schema---RDF ontology and YANG model---that must be used by an ITE to publish---via NETCONF and others---the intent semantics it supports. Particularly, the set of concepts, relations, and ontologies that can be used by tenants to define input intents.</t>
          </list>
        </t>
        <t>This document will also specify the minimum set of semantics that must be supported by any ITE and discovered by the interactions described in this section.</t>
      </section>
      <section title="Iteraction Between the ITE and Network Management Systems">
        <t>The data formats required for enabling interaction between the ITE and network management systems are as follows:
          <list style="symbols">
            <t>[MF1] Schema---RDF ontology and YANG model---that must be used by a management system to format declarations of management mechanisms and by an ITE to format their compositions. This schema and model comprehends the definitions for both management information and commands. Hence, this schema follows the definitions of <xref target="RFC9232" /> to specify data formats for telemetry transmission.</t>
          </list>
        </t>
        <t>The intefaces required for enabling interaction between the ITE and network management systems are as follows:
          <list style="symbols">
            <t>[MI1] Schema---RDF ontology and YANG model---that must be used by a management system to publish---via NETCONF and others---the management mechanisms it provides for being composed to implement policies and network services. This schema also follows the definitions of <xref target="RFC9232" /> to specify telemetry interactions.</t>
          </list>
        </t>
        <t>This document will also specify the minimum set of management mechanisms that must be provided by a management system for proper intent support.</t>
      </section>
      <section title="Iteraction Between the ITE and VIM">
        <t>The data formats required for enabling interaction between the ITE and the Virtualized Infrastructure Manager (VIM) are as follows:
          <list style="symbols">
            <t>[VF1] Schema---RDF ontology and YANG model---that must be used to format declarations of network resources and Virtual Network Functions (VNFs).</t>
            <t>[VF2] Schema---RDF ontology and YANG model---that must be used to format Network Service Descriptor (NSD).</t>
          </list>
        </t>
        <t>The intefaces required for enabling interaction between the ITE and the VIM are as follows:
          <list style="symbols">
            <t>[VI1] Schema---RDF ontology and YANG model---that must be used by a VIM to publish---via NETCONF and others---the network resources and Virtual Network Functions (VNFs) it provides.</t>
          </list>
        </t>
        <t>This document will also specify the minimum set of network resources and VNFs that must be provided by a VIM for proper intent support.</t>
      </section>
      <section title="Iteraction Between the ITE and External Services">
        <t>The data formats required for enabling interaction between the ITE and external services are as follows:
          <list style="symbols">
            <t>[EF1] Schema---RDF ontology and YANG model---that must be used to format declarations of networkintents, network resources, and VNFs. This schema will be used by elements that will use intents to interact with management systems, such as AINEMA <xref target="I-D.pedro-nmrg-ai-framework" />, which enables the ITE with Artificial Intelligence (AI) functions and which will express management decisions in terms of network intents, as shown in <xref target="TNSM-2018" />.
            </t>
          </list>
        </t>
        <t>The intefaces required for enabling interaction between the ITE and external services are as follows:
          <list style="symbols">
            <t>[EI1] Schema---RDF ontology and YANG model---that must be used by an ITE allow external agents to provide network intents and retrieve information about available resources and VNFs.</t>
          </list>
        </t>
      </section>
    </section>

    <section title="Implementation Guide">
      <t>This document will specify an abstract algorithm that allows an ITE (i.e., intent translator)
       to obtain a set of network service definitions and the composition of management mechanisms that implements the required policies or rules from a set of inputs.
       The ITE can translate an intent into a network policy for a target network <xref target="I-D.jeong-nmrg-ibn-network-management-automation"/><xref target="I-D.yang-i2nsf-security-policy-translation"/>.
       </t>
      <t>The inputs are:
          <list style="numbers">
            <t> The intent provided by the tenant or some external agent.</t>
            <t> A set of management mechanisms -- retrieved from some management system available.</t>
            <t> A set of VNFs and network resources -- retrieved from some VIM.</t>
          </list>
      </t>
      <t>The abstract algorithm helps obtaining validated network service definitions and management mechanism compositions which are valid for the available instantiation infrastructure.</t>
    </section>

    <section title="Information Model">
      <t>TBD</t>
    </section>

    <section title="Relation to Other IETF/IRTF Initiatives">
      <t>TBD</t>
    </section>

    <section anchor="section:IANA-Considerations" title="IANA Considerations">
      <t>
      This document does not require any IANA actions.
      </t>
    </section>
    
    <section anchor="Security" title="Security Considerations">
      <t>As with other AI mechanisms, a major security concern for the adoption of intelligent reasoning on external events to manage SDN/NFV systems is that the boundaries of the control and management planes are crossed to introduce information from outside. Such communications MUST be highly and heavily secured since some malfunction or explicit attacks might compromise the integrity and execution of the controlled system (i.e., target entity) such as router, switch, and firewall. However, it is up to implementers to deploy the necessary countermeasures to avoid such situations. From the design point of view, since all operations are performed within the control and/or management planes, the security level of reasoning solutions is inherited and thus determined by the security measures established by the systems conforming to such planes.</t>
    </section>

    <section anchor="Acknowledgments" title="Acknowledgments">
      <t indent="0" pn="section-appendix.a-1">
      This work was supported in part by Institute of Information &amp; Communications
      Technology Planning &amp; Evaluation (IITP) grant funded by the Korea
      Ministry of Science and ICT (MSIT)(No. 2022-0-01015, Development of
      Candidate Element Technology for Intelligent 6G Mobile Core Network).
    </t>

    </section>

  </middle>

  <back>

    <references title="Normative References">
      &RFC2119;
      &RFC9232;
      &RFC9316;
    </references>

    <references title="Informative References">
      <?rfc include='reference.I-D.jeong-nmrg-ibn-network-management-automation'?>
      <?rfc include='reference.I-D.yang-i2nsf-security-policy-translation'?>

      <?rfc include="reference.I-D.pedro-nmrg-ai-framework"?>
      <reference anchor="TNSM-2018">
        <front>
          <title>Exploiting External Events for Resource Adaptation in Virtual Computer and Network Systems, in IEEE Transactions on Network and Service Management. Vol. 15, n. 2, pp. 555--566, 2018.</title>
          <author>
            <organization>P. Martinez-Julia, V. P. Kafle, and H. Harai</organization>
          </author>
          <date year="2018" />
        </front>
      </reference>

      <reference anchor="TS-28.312">
        <front>
            <title>Intent Driven Management Services for Mobile Networks</title>
            <author surname="3GPP TS 28.312 V18.1.1" />
            <date month="September" year="2023" />
        </front>
        <seriesInfo name="Available:" value="https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=3554" />
      </reference>

      <reference anchor="TR-28.812">
        <front>
            <title>Study on Scenarios for Intent Driven Management Services for Mobile Networks</title>
            <author surname="3GPP TR 28.812 V17.1.0" />
            <date month="December" year="2020" />
        </front>
        <seriesInfo name="Available:" value="https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=3553" />
      </reference>

    </references>

<section title="Changes from draft-pedro-ite-00">
    <t>
    The following changes are made from draft-pedro-ite-00:
    <list style="symbols">
      <t>
      An intent is clearly defined as a declarative statement for a specific goal for
      a target network with new references.
      </t>

      <t>
      Intent Translation Engine is also called Intent Translator.
      </t>

      <t>
      The contents are clarified and typos are corrected.
      </t>
    </list>
    </t>
</section>


  </back>

</rfc>
