<?xml version='1.0' encoding='utf-8'?>
<rfc xmlns:xi="http://www.w3.org/2001/XInclude" version="3" category="std" consensus="true" docName="draft-ietf-quic-bit-grease-04" indexInclude="true" ipr="trust200902" number="9287" prepTime="2022-08-23T16:09:07" scripts="Common,Latin" sortRefs="true" submissionType="IETF" symRefs="true" tocDepth="3" tocInclude="true" xml:lang="en">
  <link href="https://datatracker.ietf.org/doc/draft-ietf-quic-bit-grease-04" rel="prev"/>
  <link href="https://dx.doi.org/10.17487/rfc9287" rel="alternate"/>
  <link href="urn:issn:2070-1721" rel="alternate"/>
  <front>
    <title>Greasing the QUIC Bit</title>
    <seriesInfo name="RFC" value="9287" stream="IETF"/>
    <author initials="M." surname="Thomson" fullname="Martin Thomson">
      <organization showOnFrontPage="true">Mozilla</organization>
      <address>
        <email>mt@lowentropy.net</email>
      </address>
    </author>
    <date month="08" year="2022"/>
    <area>tsv</area>
    <workgroup>quic</workgroup>
    <keyword>Header</keyword>
    <keyword>Path signal</keyword>
    <abstract pn="section-abstract">
      <t indent="0" pn="section-abstract-1">This document describes a method for negotiating the ability to send an
arbitrary value for the second-most significant bit in QUIC packets.</t>
    </abstract>
    <boilerplate>
      <section anchor="status-of-memo" numbered="false" removeInRFC="false" toc="exclude" pn="section-boilerplate.1">
        <name slugifiedName="name-status-of-this-memo">Status of This Memo</name>
        <t indent="0" pn="section-boilerplate.1-1">
            This is an Internet Standards Track document.
        </t>
        <t indent="0" pn="section-boilerplate.1-2">
            This document is a product of the Internet Engineering Task Force
            (IETF).  It represents the consensus of the IETF community.  It has
            received public review and has been approved for publication by
            the Internet Engineering Steering Group (IESG).  Further
            information on Internet Standards is available in Section 2 of 
            RFC 7841.
        </t>
        <t indent="0" pn="section-boilerplate.1-3">
            Information about the current status of this document, any
            errata, and how to provide feedback on it may be obtained at
            <eref target="https://www.rfc-editor.org/info/rfc9287" brackets="none"/>.
        </t>
      </section>
      <section anchor="copyright" numbered="false" removeInRFC="false" toc="exclude" pn="section-boilerplate.2">
        <name slugifiedName="name-copyright-notice">Copyright Notice</name>
        <t indent="0" pn="section-boilerplate.2-1">
            Copyright (c) 2022 IETF Trust and the persons identified as the
            document authors. All rights reserved.
        </t>
        <t indent="0" pn="section-boilerplate.2-2">
            This document is subject to BCP 78 and the IETF Trust's Legal
            Provisions Relating to IETF Documents
            (<eref target="https://trustee.ietf.org/license-info" brackets="none"/>) in effect on the date of
            publication of this document. Please review these documents
            carefully, as they describe your rights and restrictions with
            respect to this document. Code Components extracted from this
            document must include Revised BSD License text as described in
            Section 4.e of the Trust Legal Provisions and are provided without
            warranty as described in the Revised BSD License.
        </t>
      </section>
    </boilerplate>
    <toc>
      <section anchor="toc" numbered="false" removeInRFC="false" toc="exclude" pn="section-toc.1">
        <name slugifiedName="name-table-of-contents">Table of Contents</name>
        <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1">
          <li pn="section-toc.1-1.1">
            <t indent="0" keepWithNext="true" pn="section-toc.1-1.1.1"><xref derivedContent="1" format="counter" sectionFormat="of" target="section-1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-introduction">Introduction</xref></t>
          </li>
          <li pn="section-toc.1-1.2">
            <t indent="0" keepWithNext="true" pn="section-toc.1-1.2.1"><xref derivedContent="2" format="counter" sectionFormat="of" target="section-2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-conventions-and-definitions">Conventions and Definitions</xref></t>
          </li>
          <li pn="section-toc.1-1.3">
            <t indent="0" pn="section-toc.1-1.3.1"><xref derivedContent="3" format="counter" sectionFormat="of" target="section-3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-the-grease-quic-bit-transpo">The Grease QUIC Bit Transport Parameter</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2">
              <li pn="section-toc.1-1.3.2.1">
                <t indent="0" keepWithNext="true" pn="section-toc.1-1.3.2.1.1"><xref derivedContent="3.1" format="counter" sectionFormat="of" target="section-3.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-clearing-the-quic-bit">Clearing the QUIC Bit</xref></t>
              </li>
              <li pn="section-toc.1-1.3.2.2">
                <t indent="0" pn="section-toc.1-1.3.2.2.1"><xref derivedContent="3.2" format="counter" sectionFormat="of" target="section-3.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-using-the-quic-bit">Using the QUIC Bit</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.4">
            <t indent="0" pn="section-toc.1-1.4.1"><xref derivedContent="4" format="counter" sectionFormat="of" target="section-4"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-security-considerations">Security Considerations</xref></t>
          </li>
          <li pn="section-toc.1-1.5">
            <t indent="0" pn="section-toc.1-1.5.1"><xref derivedContent="5" format="counter" sectionFormat="of" target="section-5"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-iana-considerations">IANA Considerations</xref></t>
          </li>
          <li pn="section-toc.1-1.6">
            <t indent="0" pn="section-toc.1-1.6.1"><xref derivedContent="6" format="counter" sectionFormat="of" target="section-6"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-references">References</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.6.2">
              <li pn="section-toc.1-1.6.2.1">
                <t indent="0" pn="section-toc.1-1.6.2.1.1"><xref derivedContent="6.1" format="counter" sectionFormat="of" target="section-6.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-normative-references">Normative References</xref></t>
              </li>
              <li pn="section-toc.1-1.6.2.2">
                <t indent="0" pn="section-toc.1-1.6.2.2.1"><xref derivedContent="6.2" format="counter" sectionFormat="of" target="section-6.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-informative-references">Informative References</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.7">
            <t indent="0" pn="section-toc.1-1.7.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.a"/><xref derivedContent="" format="title" sectionFormat="of" target="name-authors-address">Author's Address</xref></t>
          </li>
        </ul>
      </section>
    </toc>
  </front>
  <middle>
    <section anchor="introduction" numbered="true" removeInRFC="false" toc="include" pn="section-1">
      <name slugifiedName="name-introduction">Introduction</name>
      <t indent="0" pn="section-1-1">The version-independent definition of QUIC <xref target="RFC8999" format="default" sectionFormat="of" derivedContent="QUIC-INVARIANTS"/>
intentionally describes a very narrow set of fields that are visible
to entities other than endpoints.  Beyond those characteristics that
are invariant, very little about the "wire image" <xref target="RFC8546" format="default" sectionFormat="of" derivedContent="RFC8546"/> of QUIC
is visible.</t>
      <t indent="0" pn="section-1-2">The second-most significant bit of the first byte in every QUIC packet is
      defined as having a fixed value in QUIC version 1 <xref target="RFC9000" format="default" sectionFormat="of" derivedContent="QUIC"/>.


 The purpose of having a fixed value is to allow endpoints to efficiently distinguish QUIC from other protocols; see  <xref target="I-D.ietf-avtcore-rfc7983bis" format="default" sectionFormat="of" derivedContent="DEMUX"/> for a description of a
system that might use this property.  As this bit can identify a packet as QUIC,
it is sometimes referred to as the "QUIC Bit".</t>
      <t indent="0" pn="section-1-3">Where endpoints and the intermediaries that support them do not depend on the
QUIC Bit having a fixed value, sending the same value in every packet is more of a 
liability than an asset.  If systems come to depend on a fixed value, then it
might become infeasible to define a version of QUIC that attributes semantics to
this bit.</t>
      <t indent="0" pn="section-1-4">In order to safeguard future use of this bit, this document defines a QUIC
transport parameter that indicates that an endpoint is willing to receive QUIC
packets containing any value for this bit.  By sending different values for this
bit, the hope is that the value will remain available for future use
<xref target="RFC9170" format="default" sectionFormat="of" derivedContent="USE-IT"/>.</t>
    </section>
    <section anchor="conventions-and-definitions" numbered="true" removeInRFC="false" toc="include" pn="section-2">
      <name slugifiedName="name-conventions-and-definitions">Conventions and Definitions</name>
      <t indent="0" pn="section-2-1">
    The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
    "<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as
    described in BCP 14 <xref target="RFC2119" format="default" sectionFormat="of" derivedContent="RFC2119"/> <xref target="RFC8174" format="default" sectionFormat="of" derivedContent="RFC8174"/> 
    when, and only when, they appear in all capitals, as shown here.
      </t>
      <t indent="0" pn="section-2-2">This document uses terms and notational conventions from <xref target="RFC9000" format="default" sectionFormat="of" derivedContent="QUIC"/>.</t>
    </section>
    <section anchor="the-grease-quic-bit-transport-parameter" numbered="true" removeInRFC="false" toc="include" pn="section-3">
      <name slugifiedName="name-the-grease-quic-bit-transpo">The Grease QUIC Bit Transport Parameter</name>
      <t indent="0" pn="section-3-1">The grease_quic_bit transport parameter (0x2ab2) is defined for QUIC
version 1 <xref target="RFC9000" format="default" sectionFormat="of" derivedContent="QUIC"/>.  This transport parameter can be sent by both client and
server.  The transport parameter is sent with an empty value; an endpoint that
understands this transport parameter <bcp14>MUST</bcp14> treat receipt of a non-empty value of
the transport parameter as a connection error of type TRANSPORT_PARAMETER_ERROR.</t>
      <t indent="0" pn="section-3-2">An endpoint that advertises the grease_quic_bit transport parameter <bcp14>MUST</bcp14> accept
packets with the QUIC Bit set to a value of 0.  The QUIC Bit is defined as the
second-most significant bit of the first byte of QUIC packets (that is, the
value 0x40).</t>
      <section anchor="clearing-the-quic-bit" numbered="true" removeInRFC="false" toc="include" pn="section-3.1">
        <name slugifiedName="name-clearing-the-quic-bit">Clearing the QUIC Bit</name>
        <t indent="0" pn="section-3.1-1">Endpoints that receive the grease_quic_bit transport parameter from a peer
<bcp14>SHOULD</bcp14> set the QUIC Bit to an unpredictable value unless another extension
assigns specific meaning to the value of the bit.</t>
        <t indent="0" pn="section-3.1-2">Endpoints can set the QUIC Bit to 0 on all packets that are sent after receiving
and processing transport parameters. This could include Initial, Handshake, and
Retry packets.</t>
        <t indent="0" pn="section-3.1-3">A client <bcp14>MAY</bcp14> also set the QUIC Bit to 0 in Initial, Handshake, or 0-RTT packets
that are sent prior to receiving transport parameters from the server.  However,
a client <bcp14>MUST NOT</bcp14> set the QUIC Bit to 0 unless the Initial packets it sends
include a token provided by the server in a NEW_TOKEN frame (<xref section="19.7" sectionFormat="of" target="RFC9000" format="default" derivedLink="https://rfc-editor.org/rfc/rfc9000#section-19.7" derivedContent="QUIC"/>), received less than 604800 seconds (7 days) prior on a connection where
the server also included the grease_quic_bit transport parameter.</t>
        <aside pn="section-3.1-4">
          <t indent="0" pn="section-3.1-4.1">This 7-day limit allows for changes in server configuration.  If server
configuration changes and a client does not set the QUIC Bit, then it is
possible that a server will drop packets, resulting in connection failures.</t>
        </aside>
        <t indent="0" pn="section-3.1-5">A server <bcp14>MUST</bcp14> set the QUIC Bit to 0 only after processing transport parameters
from a client.  A server <bcp14>MUST NOT</bcp14> remember that a client negotiated the
extension in a previous connection and set the QUIC Bit to 0 based on that
information.</t>
        <t indent="0" pn="section-3.1-6">An endpoint <bcp14>MUST NOT</bcp14> set the QUIC Bit to 0 without knowing whether the peer
supports the extension.  As Stateless Reset packets (<xref section="10.3" sectionFormat="of" target="RFC9000" format="default" derivedLink="https://rfc-editor.org/rfc/rfc9000#section-10.3" derivedContent="QUIC"/>)
are only used after a loss of connection state, endpoints are unlikely to be
able to set the QUIC Bit to 0 on Stateless Reset packets.</t>
      </section>
      <section anchor="using-the-quic-bit" numbered="true" removeInRFC="false" toc="include" pn="section-3.2">
        <name slugifiedName="name-using-the-quic-bit">Using the QUIC Bit</name>
        <t indent="0" pn="section-3.2-1">The purpose of this extension is to allow for the use of the QUIC Bit by later
extensions.</t>
        <t indent="0" pn="section-3.2-2">Extensions to QUIC that define semantics for the QUIC Bit can be negotiated at
the same time as the grease_quic_bit transport parameter.  In this case, a
recipient needs to be able to distinguish a randomized value from a value
carrying information according to the extension.  Extensions that use the QUIC
Bit <bcp14>MUST</bcp14> negotiate their use prior to acting on any semantic.</t>
        <t indent="0" pn="section-3.2-3">For example, an extension might define a transport parameter that is sent in
addition to the grease_quic_bit transport parameter.  Though the value of the
QUIC Bit in packets received by a peer might be set according to rules defined
by the extension, they might also be randomized as specified in this document.</t>
        <t indent="0" pn="section-3.2-4">The receipt of a transport parameter for an extension that uses the QUIC Bit could be
used to confirm that a peer supports the semantic defined in the extension.  To
avoid acting on a randomized signal, the extension can require that endpoints
set the QUIC Bit according to the rules of the extension but defer acting on
the information conveyed until the transport parameter for the extension is
received.</t>
        <t indent="0" pn="section-3.2-5">Extensions that define semantics for the QUIC Bit can be negotiated without
using the grease_quic_bit transport parameter.  However, including both
extensions allows for the QUIC Bit to be greased even if the alternative use is
not supported.</t>
      </section>
    </section>
    <section anchor="security-considerations" numbered="true" removeInRFC="false" toc="include" pn="section-4">
      <name slugifiedName="name-security-considerations">Security Considerations</name>
      <t indent="0" pn="section-4-1">This document introduces no new security considerations for endpoints or
entities that can rely on endpoint cooperation.  However, this change makes the
task of identifying QUIC more difficult without cooperation of endpoints.  This
sometimes works counter to the security goals of network operators who rely on
network classification to identify threats; see <xref target="I-D.ietf-quic-manageability" section="3.1" sectionFormat="of" format="default" derivedLink="https://datatracker.ietf.org/doc/html/draft-ietf-quic-manageability-18#section-3.1" derivedContent="MANAGEABILITY"/> for a more comprehensive treatment of this topic.</t>
    </section>
    <section anchor="iana-considerations" numbered="true" removeInRFC="false" toc="include" pn="section-5">
      <name slugifiedName="name-iana-considerations">IANA Considerations</name>
      <t indent="0" pn="section-5-1">This document registers the grease_quic_bit transport parameter in the "QUIC
Transport Parameters" registry established in <xref section="22.3" sectionFormat="of" target="RFC9000" format="default" derivedLink="https://rfc-editor.org/rfc/rfc9000#section-22.3" derivedContent="QUIC"/>.  The
following fields are registered:</t>
      <dl indent="3" newline="false" spacing="normal" pn="section-5-2">
        <dt pn="section-5-2.1">Value:</dt>
        <dd pn="section-5-2.2">
          <t indent="0" pn="section-5-2.2.1">0x2ab2</t>
        </dd>
        <dt pn="section-5-2.3">Parameter Name:</dt>
        <dd pn="section-5-2.4">
          <t indent="0" pn="section-5-2.4.1">grease_quic_bit</t>
        </dd>
        <dt pn="section-5-2.5">Status:</dt>
        <dd pn="section-5-2.6">
          <t indent="0" pn="section-5-2.6.1">Permanent</t>
        </dd>
        <dt pn="section-5-2.7">Specification:</dt>
        <dd pn="section-5-2.8">
          <t indent="0" pn="section-5-2.8.1">RFC 9287</t>
        </dd>
        <dt pn="section-5-2.9">Date:</dt>
        <dd pn="section-5-2.10">
          <t indent="0" pn="section-5-2.10.1">2022-07-13</t>
        </dd>
        <dt pn="section-5-2.11">Change Controller:</dt>
        <dd pn="section-5-2.12">
          <t indent="0" pn="section-5-2.12.1">IETF (iesg@ietf.org)</t>
        </dd>
        <dt pn="section-5-2.13">Contact:</dt>
        <dd pn="section-5-2.14">
          <t indent="0" pn="section-5-2.14.1">QUIC Working Group (quic@ietf.org)</t>
        </dd>
        <dt pn="section-5-2.15">Notes:</dt>
        <dd pn="section-5-2.16">
          <t indent="0" pn="section-5-2.16.1">(none)</t>
        </dd>
      </dl>
    </section>
  </middle>
  <back>
    <displayreference target="RFC9000" to="QUIC"/>
    <displayreference target="RFC8999" to="QUIC-INVARIANTS"/>
    <displayreference target="I-D.ietf-avtcore-rfc7983bis" to="DEMUX"/>
    <displayreference target="RFC9170" to="USE-IT"/>
    <displayreference target="I-D.ietf-quic-manageability" to="MANAGEABILITY"/>
    <references pn="section-6">
      <name slugifiedName="name-references">References</name>
      <references pn="section-6.1">
        <name slugifiedName="name-normative-references">Normative References</name>
        <reference anchor="RFC9000" target="https://www.rfc-editor.org/info/rfc9000" quoteTitle="true" derivedAnchor="QUIC">
          <front>
            <title>QUIC: A UDP-Based Multiplexed and Secure Transport</title>
            <author fullname="J. Iyengar" initials="J" role="editor" surname="Iyengar"/>
            <author fullname="M. Thomson" initials="M" role="editor" surname="Thomson"/>
            <date month="May" year="2021"/>
            <abstract>
              <t indent="0">This document defines the core of the QUIC transport protocol.  QUIC provides applications with flow-controlled streams for structured communication, low-latency connection establishment, and network path migration.  QUIC includes security measures that ensure confidentiality, integrity, and availability in a range of deployment circumstances.  Accompanying documents describe the integration of TLS for key negotiation, loss detection, and an exemplary congestion control algorithm.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="9000"/>
          <seriesInfo name="DOI" value="10.17487/RFC9000"/>
        </reference>
        <reference anchor="RFC8999" target="https://www.rfc-editor.org/info/rfc8999" quoteTitle="true" derivedAnchor="QUIC-INVARIANTS">
          <front>
            <title>Version-Independent Properties of QUIC</title>
            <author fullname="M. Thomson" initials="M" surname="Thomson"/>
            <date month="May" year="2021"/>
            <abstract>
              <t indent="0">This document defines the properties of the QUIC transport protocol that are common to all versions of the protocol.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8999"/>
          <seriesInfo name="DOI" value="10.17487/RFC8999"/>
        </reference>
        <reference anchor="RFC2119" target="https://www.rfc-editor.org/info/rfc2119" quoteTitle="true" derivedAnchor="RFC2119">
          <front>
            <title>Key words for use in RFCs to Indicate Requirement Levels</title>
            <author fullname="S. Bradner" initials="S" surname="Bradner"/>
            <date month="March" year="1997"/>
            <abstract>
              <t indent="0">In many standards track documents several words are used to signify the requirements in the specification.  These words are often capitalized.  This document defines these words as they should be interpreted in IETF documents.  This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="2119"/>
          <seriesInfo name="DOI" value="10.17487/RFC2119"/>
        </reference>
        <reference anchor="RFC8174" target="https://www.rfc-editor.org/info/rfc8174" quoteTitle="true" derivedAnchor="RFC8174">
          <front>
            <title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
            <author fullname="B. Leiba" initials="B" surname="Leiba"/>
            <date month="May" year="2017"/>
            <abstract>
              <t indent="0">RFC 2119 specifies common key words that may be used in protocol specifications.  This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="8174"/>
          <seriesInfo name="DOI" value="10.17487/RFC8174"/>
        </reference>
      </references>
      <references pn="section-6.2">
        <name slugifiedName="name-informative-references">Informative References</name>
        <reference anchor="I-D.ietf-avtcore-rfc7983bis" quoteTitle="true" target="https://datatracker.ietf.org/doc/html/draft-ietf-avtcore-rfc7983bis-06" derivedAnchor="DEMUX">
          <front>
            <title>Multiplexing Scheme Updates for QUIC</title>
            <author fullname="Bernard Aboba">
              <organization showOnFrontPage="true">Microsoft Corporation</organization>
            </author>
            <author fullname="Gonzalo Salgueiro">
              <organization showOnFrontPage="true">Cisco Systems</organization>
            </author>
            <author fullname="Colin Perkins">
              <organization showOnFrontPage="true">University of Glasgow</organization>
            </author>
            <date month="August" day="5" year="2022"/>
            <abstract>
              <t indent="0">   This document defines how QUIC, Datagram Transport Layer Security
   (DTLS), Real-time Transport Protocol (RTP), RTP Control Protocol
   (RTCP), Session Traversal Utilities for NAT (STUN), Traversal Using
   Relays around NAT (TURN), and ZRTP packets are multiplexed on a
   single receiving socket.

   This document updates RFC 7983 and RFC 5764.

              </t>
            </abstract>
          </front>
          <seriesInfo name="Internet-Draft" value="draft-ietf-avtcore-rfc7983bis-06"/>
          <format type="TXT" target="https://www.ietf.org/archive/id/draft-ietf-avtcore-rfc7983bis-06.txt"/>
          <refcontent>Work in Progress</refcontent>
        </reference>
        <reference anchor="I-D.ietf-quic-manageability" quoteTitle="true" target="https://datatracker.ietf.org/doc/html/draft-ietf-quic-manageability-18" derivedAnchor="MANAGEABILITY">
          <front>
            <title>Manageability of the QUIC Transport Protocol</title>
            <author fullname="Mirja Kuehlewind">
              <organization showOnFrontPage="true">Ericsson</organization>
            </author>
            <author fullname="Brian Trammell">
              <organization showOnFrontPage="true">Google Switzerland GmbH</organization>
            </author>
            <date month="July" day="15" year="2022"/>
            <abstract>
              <t indent="0">   This document discusses manageability of the QUIC transport protocol,
   focusing on the implications of QUIC's design and wire image on
   network operations involving QUIC traffic.  It is intended as a
   "user's manual" for the wire image, providing guidance for network
   operators and equipment vendors who rely on the use of transport-
   aware network functions.

              </t>
            </abstract>
          </front>
          <seriesInfo name="Internet-Draft" value="draft-ietf-quic-manageability-18"/>
          <format type="TXT" target="https://www.ietf.org/archive/id/draft-ietf-quic-manageability-18.txt"/>
          <refcontent>Work in Progress</refcontent>
        </reference>
        <reference anchor="RFC8546" target="https://www.rfc-editor.org/info/rfc8546" quoteTitle="true" derivedAnchor="RFC8546">
          <front>
            <title>The Wire Image of a Network Protocol</title>
            <author fullname="B. Trammell" initials="B" surname="Trammell"/>
            <author fullname="M. Kuehlewind" initials="M" surname="Kuehlewind"/>
            <date month="April" year="2019"/>
            <abstract>
              <t indent="0">This document defines the wire image, an abstraction of the information available to an on-path non-participant in a networking protocol.  This abstraction is intended to shed light on the implications that increased encryption has for network functions that use the wire image.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8546"/>
          <seriesInfo name="DOI" value="10.17487/RFC8546"/>
        </reference>
        <reference anchor="RFC9170" target="https://www.rfc-editor.org/info/rfc9170" quoteTitle="true" derivedAnchor="USE-IT">
          <front>
            <title>Long-Term Viability of Protocol Extension Mechanisms</title>
            <author fullname="M. Thomson" initials="M" surname="Thomson"/>
            <author fullname="T. Pauly" initials="T" surname="Pauly"/>
            <date month="December" year="2021"/>
            <abstract>
              <t indent="0">The ability to change protocols depends on exercising the extension and version-negotiation mechanisms that support change.  This document explores how regular use of new protocol features can ensure that it remains possible to deploy changes to a protocol.  Examples are given where lack of use caused changes to be more difficult or costly.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="9170"/>
          <seriesInfo name="DOI" value="10.17487/RFC9170"/>
        </reference>
      </references>
    </references>
    <section anchor="authors-addresses" numbered="false" removeInRFC="false" toc="include" pn="section-appendix.a">
      <name slugifiedName="name-authors-address">Author's Address</name>
      <author initials="M." surname="Thomson" fullname="Martin Thomson">
        <organization showOnFrontPage="true">Mozilla</organization>
        <address>
          <email>mt@lowentropy.net</email>
        </address>
      </author>
    </section>
  </back>
</rfc>
