One document matched: draft-petithuguenin-behave-turn-uris-08.xml

<?xml version="1.0" ?>
<?rfc compact="yes" ?>
<?rfc strict="no" ?>
<?rfc symrefs="yes" ?>
<?rfc toc="yes" ?>
<rfc category="std" docName="draft-petithuguenin-behave-turn-uris-08" ipr="trust200902">
	<front>
		<title abbrev="TURN URIs">Traversal Using Relays around NAT (TURN) Uniform Resource Identifiers</title>

		<author fullname="Marc Petit-Huguenin" initials="M." surname="Petit-Huguenin">
			<organization>Impedance Mismatch</organization>

			<address>
				<email>petithug@acm.org</email>
			</address>
		</author>

		<author fullname="Suhas Nandakumar" initials="S." surname="Nandakumar">
			<organization>Cisco Systems</organization>

			<address>
				<postal>
					<street>170 West Tasman Drive</street>
					<city>San Jose</city>
					<region>CA</region>
					<code>95134</code>
					<country>US</country>
				</postal>

				<email>snandaku@cisco.com</email>
			</address>
		</author>

		<author fullname="Gonzalo Salgueiro" initials="G." surname="Salgueiro">
			<organization>Cisco Systems</organization>

			<address>
				<postal>
					<street>7200-12 Kit Creek Road</street>
					<city>Research Triangle Park</city>
					<region>NC</region>
					<code>27709</code>
					<country>US</country>
				</postal>

				<email>gsalguei@cisco.com</email>
			</address>
		</author>

		<author fullname="Paul E. Jones" initials="P." surname="Jones">
			<organization>Cisco Systems</organization>

			<address>
				<postal>
					<street>7025 Kit Creek Road</street>
					<city>Research Triangle Park</city>
					<region>NC</region>
					<code>27709</code>
					<country>US</country>
				</postal>

				<email>paulej@packetizer.com</email>
			</address>
		</author>

		<date day="09" month="September" year="2013"/>
		<area>TSV</area>
		<workgroup>BEHAVE</workgroup>

		<abstract>
			<t>
				This document specifies the syntax of Uniform Resource Identifier (URI) schemes for the Traversal Using Relays around NAT (TURN) protocol.
				It defines two URI schemes to provision the <xref target="RFC5928">TURN Resolution Mechanism</xref>.
			</t>
		</abstract>
	</front>

	<middle>
		<section anchor="section.intro" title="Introduction">
			<t>This document specifies the syntax and semantics of the Uniform Resource Identifier (URI) scheme for the Traversal Using Relays around NAT (TURN) protocol.</t>

			<t>
				The TURN protocol is a specification allowing hosts behind NAT to control the operation of a relay server.
				The relay server allows hosts to exchange packets with its peers.
				The peers themselves may also be behind NATs.
				<xref target="RFC5766">RFC 5766</xref> defines the specifics of the TURN protocol.
			</t>

			<t>
				The "turn" and "turns" URI schemes are used to designate a TURN server (also known as a relay) on Internet hosts accessible using the TURN protocol.
				With the advent of standards such as <xref target="WEBRTC"/>, we anticipate a plethora of endpoints and web applications to be able to identify and communicate with such a TURN server to carry out the TURN protocol.
				This also implies those endpoints and/or applications to be provisioned with appropriate configuration required to identify the TURN server.
				Having an inconsistent syntax has its drawbacks and can result in non-interoperable solutions.
				It can result in solutions that are ambiguous and have implementation limitations on the different aspects of the syntax and alike.
				The "turn/turns" URI scheme helps alleviate most of these issues by providing a consistent way to describe, configure and exchange the information identifying a TURN server.
				This would also prevent the shortcomings inherent with encoding similar information in non-uniform syntaxes such as the ones proposed in <xref target="WEBRTC"/>, for example.
			</t>

			<t>
<xref target="RFC5928"/> defines a resolution mechanism to convert a secure flag, a host name or IP address, a potentially empty port, and a potentially empty transport to a list of IP address, port, and TURN transport tuples.</t>

			<t>To simplify the provisioning of TURN clients, this document defines a TURN and a TURNS URI scheme that can carry the four components needed for the resolution mechanism.</t>
		</section>

		<section anchor="section.terminology" title="Terminology">
			<t>
				The key words "MUST", "MUST NOT", "REQUIRED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in <xref target="RFC2119"/> when they appear in ALL CAPS.
				When these words are not in ALL CAPS (such as "should" or "Should"), they have their usual English meanings, and are not to be interpreted as RFC 2119 key words.
			</t>
		</section>

		<section anchor="section.definition" title="Definitions of the TURN and TURNS URI">
			<section anchor="section.definition.syntax" title="URI Scheme Syntax">
				<t>A TURN/TURNS URI has the following formal ABNF syntax <xref target="RFC5234"/>:</t>

				<figure>
					<artwork type="abnf"><![CDATA[
turnURI       = scheme ":" host [ ":" port ]
                [ "?transport=" transport ]
scheme        = "turn" / "turns"
transport     = "udp" / "tcp" / transport-ext
transport-ext = 1*unreserved]]>
					</artwork>
				</figure>

				<t>
					<host>, and <port> are specified in <xref target="RFC3986"/>.
					While these two ABNF productions are defined in <xref target="RFC3986"/> as components of the generic hierarchical URI, this does not imply that that the turn and turns schemes are hierarchical URIs.
					Developers MUST NOT use a generic hierarchical URI parser to parse a turn or turns URI.
				</t>

				<t>
					The <host>, <port> and <transport> components are passed without modification to the <xref target="RFC5928"/> algorithm.
					<secure> is set to false if <scheme> is equal to "turn" and set to true if <scheme> is equal to "turns" and passed to the <xref target="RFC5928"/> algorithm with the other components.
				</t>
			</section>

			<section anchor="section.definition.semantics" title="URI Scheme Semantics">
				<t>
					The "turn" and "turns" URI schemes are used to designate a TURN server (also known as a relay) on Internet hosts accessible using the TURN protocol.
					The TURN protocol supports sending messages over UDP, TCP or TLS-over-TCP.
					The "turns" URI scheme MUST be used when TURN is run over TLS-over-TCP (or in the future DTLS-over-UDP) and the "turn" scheme MUST be used otherwise.
				</t>

				<t>The required <host> part of the "turn" URI denotes the TURN server host.</t>

				<t>
					As specified in <xref target="RFC5766"/> and <xref target="RFC5928"/>, the <port> part, if present, denotes the port on which the TURN server is awaiting connection requests.
					If it is absent, the default port is 3478 for both UDP and TCP.
					The default port for TURN over TLS is 5349.
				</t>
			</section>
		</section>

		<section anchor="section.ref-impl" title="Implementation Status">
			<t>Note to RFC Editor: Please remove this section and the reference to <xref target="RFC6982"/> before publication.</t>

			<t>
				This section records the status of known implementations of the protocol defined by this specification at the time of posting of this Internet-Draft, and is based on a proposal described in <xref target="RFC6982"/>.
				The description of implementations in this section is intended to assist the IETF in its decision processes in progressing drafts to RFCs.
				Please note that the listing of any individual implementation here does not imply endorsement by the IETF.
				Furthermore, no effort has been spent to verify the information presented here that was supplied by IETF contributors.
				This is not intended as, and must not be construed to be, a catalog of available implementations or their features.
				Readers are advised to note that other implementations may exist.
			</t>

			<t>
				According to <xref target="RFC6982"/>, "this will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature.
				It is up to the individual working groups to use this information as they see fit".
			</t>

			<section anchor="section.impl-status.turnuri" title="turnuri">
				<t>
					<list style="hanging">
						<t hangText="Organization: ">Impedance Mismatch</t>
						<t hangText="Name: ">
							turnuri 0.3.4
							http://debian.implementers.org/stable/source/turnuri.tar.gz
						</t>
						<t hangText="Description: ">A reference implementation of this document and of <xref target="RFC5928">RFC 5928</xref>.</t>
						<t hangText="Level of maturity: ">Beta.</t>
						<t hangText="Coverage: ">Fully implements this specification and RFC 5928.</t>
						<t hangText="Licensing: ">AGPL3</t>
						<t hangText="Implementation experience: "/>
						<t hangText="Contact: ">Marc Petit-Huguenin <marc@petit-huguenin.org>.</t>
					</list>
				</t>
			</section>

			<section anchor="section.impl-status.libjingle" title="libjingle">
				<t>
					<list style="hanging">
						<t hangText="Organization: ">Google Inc.</t>
						<t hangText="Name: ">
							libjingle revision 4831
							https://code.google.com/p/chromium/codesearch#chromium/src/third_party/libjingle/source/talk/app/webrtc/peerconnection.cc
						</t>
						<t hangText="Description: ">Libjingle is a set of components provided by Google to implement Jingle protocols XEP-166 (http://xmpp.org/extensions/xep-0166.html) and XEP-167 (http://xmpp.org/extensions/xep-0167.html).</t>
						<t hangText="Level of maturity: ">Beta.</t>
						<t hangText="Coverage: ">
							Implements draft-petithuguenin-behave-turn-uris-07 without IPv6.
							The turn and turns schemes are parsed, and TLS is used when the secure bit is set.
							The libjingle library does not use the SRV and NAPTR RR from the RFC 5928 resolution mechanism.
						</t>
						<t hangText="Licensing: ">BSD 3-clauses license.</t>
						<t hangText="Contact: ">https://code.google.com/p/chromium/</t>
					</list>
				</t>
			</section>

			<section anchor="section.impl-status.firefox" title="Firefox">
				<t>
					<list style="hanging">
						<t hangText="Organization: ">Mozilla</t>
						<t hangText="Name: ">
							Firefox Aurora 21
							http://hg.mozilla.org/mozilla-central/rev/6b5016ab9ebb
						</t>
						<t hangText="Description: ">Mozilla Firefox is a free and open source web browser.</t>
						<t hangText="Level of maturity: ">Beta.</t>
						<t hangText="Coverage: ">
							Implements draft-petithuguenin-behave-turn-uri-03 without RFC 5928.
							The mozilla code parses the turn and turns schemes but does not seems to use TLS.
						</t>
						<t hangText="Licensing: ">Mozilla Public License, v2.0.</t>
						<t hangText="Contact: ">http://www.mozilla.org/en-US/firefox/channel/</t>
					</list>
				</t>
			</section>
		</section>

		<section anchor="section.security" title="Security Considerations">
			<t>
				Security considerations for the resolution mechanism are discussed in Section 5 of <xref target="RFC5928"/>.
				Note that this section contains normative text defining authentication procedures to be followed by turn clients when TLS is used.
			</t>

			<t>The "turn" and "turns" URI schemes do not introduce any specific security issues beyond the security considerations discussed in <xref target="RFC3986"/>.</t>

			<t>
				While the turn and turns URIs do not themselves include the username or password that will be used to authenticate the TURN client, in certain environments, such as WebRTC, the username and password will almost certainly be provisioned remotely by an external agent at the same time as a turns URI is sent to that client.
				Thus, in such situations, if the username and password were received in clear there would be little or no benefit to using a turns URI.
				For this reason a TURN client MUST ensure that the username, password, and turns URI and any other security-relevant parameters are received with equivalent security before using the turns URI.
				Receiving those parameters over another TLS session can provide the appropriate level of security, if both TLS sessions are similarly parameterised, e.g.  with commensurate strength ciphersuites.
			</t>
		</section>

		<section anchor="section.iana" title="IANA Considerations">
			<t>This section contains the registration information for the "turn" and "turns" URI Schemes (in accordance with <xref target="RFC4395"/>).</t>

			<section title="TURN URI Registration">
				<t>URI scheme name: turn</t>
				<t>Status: permanent</t>
				<t>URI scheme syntax: See <xref target="section.definition.syntax"/>.</t>
				<t>URI scheme semantics: See <xref target="section.definition.semantics"/>.</t>
				<t>Encoding considerations: There are no encoding considerations beyond those in <xref target="RFC3986"/>.</t>
				<t>Applications/protocols that use this URI scheme name:</t>
				<t>
					<list>
						<t>The "turn" URI scheme is intended to be used by applications with a need to identify a TURN server to be used for NAT traversal.</t>
					</list>
				</t>
				<t>Interoperability considerations: N/A</t>
				<t>Security considerations: See <xref target="section.security"/>.</t>
				<t>Contact: Marc Petit-Huguenin <petithug@acm.org></t>
				<t>Author/Change controller: The IESG</t>
				<t>References: RFCXXXX</t>
				<t>[[NOTE TO RFC EDITOR: Please change XXXX to the number assigned to this specification, and remove this paragraph on publication.]]</t>
			</section>

			<section title="TURNS URI Registration">
				<t>URI scheme name: turns</t>
				<t>Status: permanent</t>
				<t>URI scheme syntax: See <xref target="section.definition.syntax"/>.</t>
				<t>URI scheme semantics: See <xref target="section.definition.semantics"/>.</t>
				<t>Encoding considerations: There are no encoding considerations beyond those in <xref target="RFC3986"/>.</t>
				<t>Applications/protocols that use this URI scheme name:</t>
				<t>
					<list>
						<t>The "turns" URI scheme is intended to be used by applications with a need to identify a TURN server to be used for NAT traversal over a secure connection.</t>
					</list>
				</t>

				<t>Interoperability considerations: N/A</t>
				<t>Security considerations: See <xref target="section.security"/>.</t>
				<t>Contact: Marc Petit-Huguenin <petithug@acm.org></t>
				<t>Author/Change controller: The IESG</t>
				<t>References: RFCXXXX</t>
				<t>[[NOTE TO RFC EDITOR: Please change XXXX to the number assigned to this specification, and remove this paragraph on publication.]]</t>
			</section>
		</section>

		<section anchor="section.acknowledgements" title="Acknowledgements">
			<t>Thanks to Margaret Wasserman, Magnus Westerlund, Juergen Schoenwaelder, Sean Turner, Ted Hardie, Dave Thaler, Alfred E. Heggestad, Eilon Yardeni, Dan Wing, Alfred Hoenes, and Jim Kleck for the comments, suggestions and questions that helped improve the draft-petithuguenin-behave-turn-uri-bis document.</t>
			<t>Many thanks to Cullen Jennings for his detailed review and thoughtful comments on the draft-nandakumar-rtcweb-turn-uri document.</t>
			<t>Thanks to Bjoern Hoehrmann, Dan Wing, Russ Housley, S. Moonesamy, Graham Klyne, Harald Alvestrand, Hadriel Kaplan, Tina Tsou, Spencer Dawkins, Ted Lemon, Barry Leiba, Pete Resnick, and Stephen Farrell for the comments, suggestions and questions that helped improve this document.</t>

			<t>
				The authors would also like to express their gratitude to Dan Wing for his assistance in shepherding this document.
				We also want to thank Gonzalo Camarillo, the Real-time Applications and Infrastructure Director, for sponsoring this document as well his careful reviews.
			</t>
		</section>
	</middle>

	<back>
		<references title="Normative References">
			<reference anchor="RFC2119">
	
	<front>
	<title abbrev="RFC Key Words">Key words for use in RFCs to Indicate Requirement Levels</title>
	<author fullname="Scott Bradner" initials="S." surname="Bradner">
	<organization>Harvard University</organization>
	<address>
	<postal>
	<street>1350 Mass. Ave.</street>
	<street>Cambridge</street>
	<street>MA 02138</street>
</postal>
	<phone>- +1 617 495 3864</phone>
	<email>sob@harvard.edu</email>
</address>
</author>
	<date month="March" year="1997"/>
	<area>General</area>
	<keyword>keyword</keyword>
	<abstract>
	<t>
	   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.  Authors who follow these guidelines
	   should incorporate this phrase near the beginning of their document:
	
	<list>
	<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
	      RFC 2119.
	</t>
</list>
</t>
	<t>
	   Note that the force of these words is modified by the requirement
	   level of the document in which they are used.
	</t>
</abstract>
</front>
	
	<seriesInfo name="BCP" value="14"/>
	<seriesInfo name="RFC" value="2119"/>
	<format octets="4723" target="ftp://ftp.isi.edu/in-notes/rfc2119.txt" type="TXT"/>
	<format octets="17491" target="http://xml.resource.org/public/rfc/html/rfc2119.html" type="HTML"/>
	<format octets="5777" target="http://xml.resource.org/public/rfc/xml/rfc2119.xml" type="XML"/>
	</reference>

			<reference anchor="RFC3986">
	
	<front>
	<title abbrev="URI Generic Syntax">Uniform Resource Identifier (URI): Generic Syntax</title>
	<author fullname="Tim Berners-Lee" initials="T." surname="Berners-Lee">
	<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
	<address>
	<postal>
	<street>Massachusetts Institute of Technology</street>
	<street>77 Massachusetts Avenue</street>
	<city>Cambridge</city>
	<region>MA</region>
	<code>02139</code>
	<country>USA</country>
</postal>
	<phone>+1-617-253-5702</phone>
	<facsimile>+1-617-258-5999</facsimile>
	<email>timbl@w3.org</email>
	<uri>http://www.w3.org/People/Berners-Lee/</uri>
</address>
</author>
	<author fullname="Roy T. Fielding" initials="R." surname="Fielding">
	<organization abbrev="Day Software">Day Software</organization>
	<address>
	<postal>
	<street>5251 California Ave., Suite 110</street>
	<city>Irvine</city>
	<region>CA</region>
	<code>92617</code>
	<country>USA</country>
</postal>
	<phone>+1-949-679-2960</phone>
	<facsimile>+1-949-679-2972</facsimile>
	<email>fielding@gbiv.com</email>
	<uri>http://roy.gbiv.com/</uri>
</address>
</author>
	<author fullname="Larry Masinter" initials="L." surname="Masinter">
	<organization abbrev="Adobe Systems">Adobe Systems Incorporated</organization>
	<address>
	<postal>
	<street>345 Park Ave</street>
	<city>San Jose</city>
	<region>CA</region>
	<code>95110</code>
	<country>USA</country>
</postal>
	<phone>+1-408-536-3024</phone>
	<email>LMM@acm.org</email>
	<uri>http://larry.masinter.net/</uri>
</address>
</author>
	<date month="January" year="2005"/>
	<area>Applications</area>
	<keyword>uniform resource identifier</keyword>
	<keyword>URI</keyword>
	<keyword>URL</keyword>
	<keyword>URN</keyword>
	<keyword>WWW</keyword>
	<keyword>resource</keyword>
	<abstract>
	<t>
	A Uniform Resource Identifier (URI) is a compact sequence of characters
	that identifies an abstract or physical resource.  This specification
	defines the generic URI syntax and a process for resolving URI references
	that might be in relative form, along with guidelines and security
	considerations for the use of URIs on the Internet.
	The URI syntax defines a grammar that is a superset of all valid URIs,
	allowing an implementation to parse the common components of a URI
	reference without knowing the scheme-specific requirements of every
	possible identifier.  This specification does not define a generative
	grammar for URIs; that task is performed by the individual
	specifications of each URI scheme.
	</t>
</abstract>
</front>
	
	<seriesInfo name="STD" value="66"/>
	<seriesInfo name="RFC" value="3986"/>
	<format octets="141811" target="ftp://ftp.isi.edu/in-notes/rfc3986.txt" type="TXT"/>
	<format octets="213584" target="http://xml.resource.org/public/rfc/html/rfc3986.html" type="HTML"/>
	<format octets="163534" target="http://xml.resource.org/public/rfc/xml/rfc3986.xml" type="XML"/>
	</reference>

			<reference anchor="RFC5234">
	
	<front>
	<title>Augmented BNF for Syntax Specifications: ABNF</title>
	<author fullname="D. Crocker" initials="D." surname="Crocker">
	<organization/>
</author>
	<author fullname="P. Overell" initials="P." surname="Overell">
	<organization/>
</author>
	<date month="January" year="2008"/>
</front>
	
	<seriesInfo name="STD" value="68"/>
	<seriesInfo name="RFC" value="5234"/>
	<format octets="26359" target="ftp://ftp.isi.edu/in-notes/rfc5234.txt" type="TXT"/>
	</reference>

			<reference anchor="RFC5766">
	
	<front>
	<title>Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN)</title>
	<author fullname="R. Mahy" initials="R." surname="Mahy">
	<organization/>
</author>
	<author fullname="P. Matthews" initials="P." surname="Matthews">
	<organization/>
</author>
	<author fullname="J. Rosenberg" initials="J." surname="Rosenberg">
	<organization/>
</author>
	<date month="April" year="2010"/>
</front>
	
	<seriesInfo name="RFC" value="5766"/>
	<format octets="172112" target="ftp://ftp.isi.edu/in-notes/rfc5766.txt" type="TXT"/>
	</reference>

			<reference anchor="RFC5928">
	
	<front>
	<title>Traversal Using Relays around NAT (TURN) Resolution Mechanism</title>
	<author fullname="M. Petit-Huguenin" initials="M." surname="Petit-Huguenin">
	<organization/>
</author>
	<date month="August" year="2010"/>
</front>
	
	<seriesInfo name="RFC" value="5928"/>
	<format octets="23993" target="ftp://ftp.isi.edu/in-notes/rfc5928.txt" type="TXT"/>
	</reference>

		</references>

		<references title="Informative References">
			<reference anchor="RFC4395">
	
	<front>
	<title>Guidelines and Registration Procedures for New URI Schemes</title>
	<author fullname="T. Hansen" initials="T." surname="Hansen">
	<organization/>
</author>
	<author fullname="T. Hardie" initials="T." surname="Hardie">
	<organization/>
</author>
	<author fullname="L. Masinter" initials="L." surname="Masinter">
	<organization/>
</author>
	<date month="February" year="2006"/>
</front>
	
	<seriesInfo name="BCP" value="35"/>
	<seriesInfo name="RFC" value="4395"/>
	<format octets="31933" target="ftp://ftp.isi.edu/in-notes/rfc4395.txt" type="TXT"/>
	</reference>


			<reference anchor="WEBRTC" target="http://www.w3.org/TR/2012/WD-webrtc-20120821">
				<front>
					<title>WebRTC 1.0: Real-time Communication Between Browsers</title>

					<author fullname="Adam Bergkvist" initials="A." surname="Bergkvist">
						<organization/>
					</author>

					<author fullname="Daniel C. Burnett" initials="D." surname="Burnett">
						<organization/>
					</author>

					<author fullname="Cullen Jennings" initials="C." surname="Jennings">
						<organization/>
					</author>

					<author fullname="Anant Narayanan" initials="A." surname="Narayanan">
						<organization/>
					</author>

					<date day="21" month="August" year="2012"/>
				</front>

				<seriesInfo name="World Wide Web Consortium WD" value="WD-webrtc-20120821"/>
				<format target="http://www.w3.org/TR/2012/WD-webrtc-20120821" type="HTML"/>
			</reference>

			<reference anchor="RFC6982">
				<front>
					<title>Improving Awareness of Running Code: The Implementation Status Section</title>

					<author fullname="Y. Sheffer" initials="Y." surname="Sheffer">
						<organization/>
					</author>

					<author fullname="A. Farrel" initials="A." surname="Farrel">
						<organization/>
					</author>

					<date month="July" year="2013"/>
				</front>

				<seriesInfo name="RFC" value="6982"/>

				<format octets="15100" target="ftp://ftp.isi.edu/in-notes/rfc6982.txt" type="TXT"/>
			</reference>
		</references>

		<section anchor="section.examples" title="Examples">
			<t>
				<xref target="example.1"/> shows how the <secure>, <port> and <transport> components are populated from various URIs.
				For all these examples, the <host> component is populated with "example.org".
			</t>

			<texttable anchor="example.1">
				<ttcol>URI</ttcol>
				<ttcol><secure></ttcol>
				<ttcol><port></ttcol>
				<ttcol><transport></ttcol>
				<c>turn:example.org</c> <c>false</c> <c/> <c/>
				<c>turns:example.org</c> <c>true</c> <c/> <c/>
				<c>turn:example.org:8000</c> <c>false</c> <c>8000</c> <c/>
				<c>turn:example.org?transport=udp</c> <c>false</c> <c/> <c>UDP</c>
				<c>turn:example.org?transport=tcp</c> <c>false</c> <c/> <c>TCP</c>
				<c>turns:example.org?transport=tcp</c> <c>true</c> <c/> <c>TLS</c>
			</texttable>
		</section>

		<section title="Design Notes">
			<t>
				<list style="symbols">
					<t>
						One recurring comment was to stop using the suffix "s" on URI scheme, and to move the secure option to a parameter (e.g. ";proto=tls").
						We decided against this idea because the STUN URI does not have a ";proto=" parameter and we would have lost the symmetry between the TURN and STUN URIs.
						A more detailed account of the reasoning behind this is available at <http://blog.marc.petit-huguenin.org/2012/09/on-design-of-stun-and-turn-uri-formats.html>
					</t>

					<t>Following the advice of RFC 4395 section 2.2., and because the TURN URI does not describe a hierarchical structure, the TURN URIs are opaque URIs.</t>

					<t>
						<password> is not used in the URIs because it is deprecated <xref target="RFC3986"/>.
						<username> and <auth> are not used in the URIs because they do not guide the resolution mechanism.
					</t>

					<t>As discussed at IETF 72 in Dublin, there is no generic parameters in the URI to prevent compatibility issues.</t>
				</list>
			</t>
		</section>

		<section title="Release notes">
			<t>This section must be removed before publication as an RFC.</t>

			<section title="Modifications between petithuguenin-behave-turn-uris-08 and petithuguenin-behave-turn-uris-07">
				<t>
					<list style="symbols">
						<t>s/eventually/potentially/</t>
						<t>Changed the ABNF to use references from RFC 3986 instead of copying them.</t>
						<t>Converted the design note about hierarchical parsers into a MUST NOT statement.</t>
						<t>Updated the RFC 6982 forms for Chrome and Firefox.</t>
						<t>Added text in security section about verifying that username, password and uris are received over a secure connection.</t>
					</list>
				</t>
			</section>
		</section>
	</back>
</rfc>