source: draft-ietf-httpbis/latest/p5-range.html @ 1355

Last change on this file since 1355 was 1355, checked in by ylafon@…, 8 years ago

Added security consideration on range flooding (See #175)

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355       content: "HTTP/1.1, Part 5"; 
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358       content: "Fielding, et al."; 
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379</style><link rel="Contents" href="#rfc.toc">
380      <link rel="Author" href="#rfc.authors">
381      <link rel="Copyright" href="#rfc.copyrightnotice">
382      <link rel="Index" href="#rfc.index">
383      <link rel="Chapter" title="1 Introduction" href="#rfc.section.1">
384      <link rel="Chapter" title="2 Range Units" href="#rfc.section.2">
385      <link rel="Chapter" title="3 Status Code Definitions" href="#rfc.section.3">
386      <link rel="Chapter" title="4 Combining Ranges" href="#rfc.section.4">
387      <link rel="Chapter" title="5 Header Field Definitions" href="#rfc.section.5">
388      <link rel="Chapter" title="6 IANA Considerations" href="#rfc.section.6">
389      <link rel="Chapter" title="7 Security Considerations" href="#rfc.section.7">
390      <link rel="Chapter" title="8 Acknowledgments" href="#rfc.section.8">
391      <link rel="Chapter" href="#rfc.section.9" title="9 References">
392      <link rel="Appendix" title="A Internet Media Type multipart/byteranges" href="#rfc.section.A">
393      <link rel="Appendix" title="B Compatibility with Previous Versions" href="#rfc.section.B">
394      <link rel="Appendix" title="C Collected ABNF" href="#rfc.section.C">
395      <link rel="Appendix" title="D Change Log (to be removed by RFC Editor before publication)" href="#rfc.section.D">
396      <meta name="generator" content="http://greenbytes.de/tech/webdav/rfc2629.xslt, Revision 1.550, 2011-05-30 14:02:12, XSLT vendor: SAXON 8.9 from Saxonica http://www.saxonica.com/">
397      <link rel="schema.dct" href="http://purl.org/dc/terms/">
398      <meta name="dct.creator" content="Fielding, R.">
399      <meta name="dct.creator" content="Gettys, J.">
400      <meta name="dct.creator" content="Mogul, J.">
401      <meta name="dct.creator" content="Frystyk, H.">
402      <meta name="dct.creator" content="Masinter, L.">
403      <meta name="dct.creator" content="Leach, P.">
404      <meta name="dct.creator" content="Berners-Lee, T.">
405      <meta name="dct.creator" content="Lafon, Y.">
406      <meta name="dct.creator" content="Reschke, J. F.">
407      <meta name="dct.identifier" content="urn:ietf:id:draft-ietf-httpbis-p5-range-latest">
408      <meta name="dct.issued" scheme="ISO8601" content="2011-07-26">
409      <meta name="dct.replaces" content="urn:ietf:rfc:2616">
410      <meta name="dct.abstract" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypermedia information systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 5 of the seven-part specification that defines the protocol referred to as &#34;HTTP/1.1&#34; and, taken together, obsoletes RFC 2616. Part 5 defines range-specific requests and the rules for constructing and combining responses to those requests.">
411      <meta name="description" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypermedia information systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 5 of the seven-part specification that defines the protocol referred to as &#34;HTTP/1.1&#34; and, taken together, obsoletes RFC 2616. Part 5 defines range-specific requests and the rules for constructing and combining responses to those requests.">
412   </head>
413   <body>
414      <table class="header">
415         <tbody>
416            <tr>
417               <td class="left">HTTPbis Working Group</td>
418               <td class="right">R. Fielding, Editor</td>
419            </tr>
420            <tr>
421               <td class="left">Internet-Draft</td>
422               <td class="right">Adobe</td>
423            </tr>
424            <tr>
425               <td class="left">Obsoletes: <a href="http://tools.ietf.org/html/rfc2616">2616</a> (if approved)
426               </td>
427               <td class="right">J. Gettys</td>
428            </tr>
429            <tr>
430               <td class="left">Intended status: Standards Track</td>
431               <td class="right">Alcatel-Lucent</td>
432            </tr>
433            <tr>
434               <td class="left">Expires: January 27, 2012</td>
435               <td class="right">J. Mogul</td>
436            </tr>
437            <tr>
438               <td class="left"></td>
439               <td class="right">HP</td>
440            </tr>
441            <tr>
442               <td class="left"></td>
443               <td class="right">H. Frystyk</td>
444            </tr>
445            <tr>
446               <td class="left"></td>
447               <td class="right">Microsoft</td>
448            </tr>
449            <tr>
450               <td class="left"></td>
451               <td class="right">L. Masinter</td>
452            </tr>
453            <tr>
454               <td class="left"></td>
455               <td class="right">Adobe</td>
456            </tr>
457            <tr>
458               <td class="left"></td>
459               <td class="right">P. Leach</td>
460            </tr>
461            <tr>
462               <td class="left"></td>
463               <td class="right">Microsoft</td>
464            </tr>
465            <tr>
466               <td class="left"></td>
467               <td class="right">T. Berners-Lee</td>
468            </tr>
469            <tr>
470               <td class="left"></td>
471               <td class="right">W3C/MIT</td>
472            </tr>
473            <tr>
474               <td class="left"></td>
475               <td class="right">Y. Lafon, Editor</td>
476            </tr>
477            <tr>
478               <td class="left"></td>
479               <td class="right">W3C</td>
480            </tr>
481            <tr>
482               <td class="left"></td>
483               <td class="right">J. Reschke, Editor</td>
484            </tr>
485            <tr>
486               <td class="left"></td>
487               <td class="right">greenbytes</td>
488            </tr>
489            <tr>
490               <td class="left"></td>
491               <td class="right">July 26, 2011</td>
492            </tr>
493         </tbody>
494      </table>
495      <p class="title">HTTP/1.1, part 5: Range Requests and Partial Responses<br><span class="filename">draft-ietf-httpbis-p5-range-latest</span></p>
496      <h1 id="rfc.abstract"><a href="#rfc.abstract">Abstract</a></h1> 
497      <p>The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypermedia information
498         systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 5 of the
499         seven-part specification that defines the protocol referred to as "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part
500         5 defines range-specific requests and the rules for constructing and combining responses to those requests.
501      </p> 
502      <h1 id="rfc.note.1"><a href="#rfc.note.1">Editorial Note (To be removed by RFC Editor)</a></h1> 
503      <p>Discussion of this draft should take place on the HTTPBIS working group mailing list (ietf-http-wg@w3.org), which is archived
504         at &lt;<a href="http://lists.w3.org/Archives/Public/ietf-http-wg/">http://lists.w3.org/Archives/Public/ietf-http-wg/</a>&gt;.
505      </p> 
506      <p>The current issues list is at &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/report/3">http://tools.ietf.org/wg/httpbis/trac/report/3</a>&gt; and related documents (including fancy diffs) can be found at &lt;<a href="http://tools.ietf.org/wg/httpbis/">http://tools.ietf.org/wg/httpbis/</a>&gt;.
507      </p> 
508      <p>The changes in this draft are summarized in <a href="#changes.since.15" title="Since draft-ietf-httpbis-p5-range-15">Appendix&nbsp;D.17</a>.
509      </p> 
510      <h1><a id="rfc.status" href="#rfc.status">Status of This Memo</a></h1>
511      <p>This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.</p>
512      <p>Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute
513         working documents as Internet-Drafts. The list of current Internet-Drafts is at <a href="http://datatracker.ietf.org/drafts/current/">http://datatracker.ietf.org/drafts/current/</a>.
514      </p>
515      <p>Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other
516         documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as “work
517         in progress”.
518      </p>
519      <p>This Internet-Draft will expire on January 27, 2012.</p>
520      <h1><a id="rfc.copyrightnotice" href="#rfc.copyrightnotice">Copyright Notice</a></h1>
521      <p>Copyright © 2011 IETF Trust and the persons identified as the document authors. All rights reserved.</p>
522      <p>This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (<a href="http://trustee.ietf.org/license-info">http://trustee.ietf.org/license-info</a>) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights
523         and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License
524         text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified
525         BSD License.
526      </p>
527      <p>This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November
528         10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to
529         allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s)
530         controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative
531         works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate
532         it into languages other than English.
533      </p>
534      <hr class="noprint">
535      <h1 class="np" id="rfc.toc"><a href="#rfc.toc">Table of Contents</a></h1>
536      <ul class="toc">
537         <li>1.&nbsp;&nbsp;&nbsp;<a href="#introduction">Introduction</a><ul>
538               <li>1.1&nbsp;&nbsp;&nbsp;<a href="#intro.requirements">Requirements</a></li>
539               <li>1.2&nbsp;&nbsp;&nbsp;<a href="#notation">Syntax Notation</a><ul>
540                     <li>1.2.1&nbsp;&nbsp;&nbsp;<a href="#core.rules">Core Rules</a></li>
541                     <li>1.2.2&nbsp;&nbsp;&nbsp;<a href="#abnf.dependencies">ABNF Rules defined in other Parts of the Specification</a></li>
542                  </ul>
543               </li>
544            </ul>
545         </li>
546         <li>2.&nbsp;&nbsp;&nbsp;<a href="#range.units">Range Units</a><ul>
547               <li>2.1&nbsp;&nbsp;&nbsp;<a href="#range.specifier.registry">Range Specifier Registry</a></li>
548            </ul>
549         </li>
550         <li>3.&nbsp;&nbsp;&nbsp;<a href="#status.code.definitions">Status Code Definitions</a><ul>
551               <li>3.1&nbsp;&nbsp;&nbsp;<a href="#status.206">206 Partial Content</a></li>
552               <li>3.2&nbsp;&nbsp;&nbsp;<a href="#status.416">416 Requested Range Not Satisfiable</a></li>
553            </ul>
554         </li>
555         <li>4.&nbsp;&nbsp;&nbsp;<a href="#combining.byte.ranges">Combining Ranges</a></li>
556         <li>5.&nbsp;&nbsp;&nbsp;<a href="#header.fields">Header Field Definitions</a><ul>
557               <li>5.1&nbsp;&nbsp;&nbsp;<a href="#header.accept-ranges">Accept-Ranges</a></li>
558               <li>5.2&nbsp;&nbsp;&nbsp;<a href="#header.content-range">Content-Range</a></li>
559               <li>5.3&nbsp;&nbsp;&nbsp;<a href="#header.if-range">If-Range</a></li>
560               <li>5.4&nbsp;&nbsp;&nbsp;<a href="#header.range">Range</a><ul>
561                     <li>5.4.1&nbsp;&nbsp;&nbsp;<a href="#byte.ranges">Byte Ranges</a></li>
562                     <li>5.4.2&nbsp;&nbsp;&nbsp;<a href="#range.retrieval.requests">Range Retrieval Requests</a></li>
563                  </ul>
564               </li>
565            </ul>
566         </li>
567         <li>6.&nbsp;&nbsp;&nbsp;<a href="#IANA.considerations">IANA Considerations</a><ul>
568               <li>6.1&nbsp;&nbsp;&nbsp;<a href="#status.code.registration">Status Code Registration</a></li>
569               <li>6.2&nbsp;&nbsp;&nbsp;<a href="#header.field.registration">Header Field Registration</a></li>
570               <li>6.3&nbsp;&nbsp;&nbsp;<a href="#range.specifier.registration">Range Specifier Registration</a></li>
571            </ul>
572         </li>
573         <li>7.&nbsp;&nbsp;&nbsp;<a href="#security.considerations">Security Considerations</a><ul>
574               <li>7.1&nbsp;&nbsp;&nbsp;<a href="#overlapping.ranges">Overlapping Ranges</a></li>
575            </ul>
576         </li>
577         <li>8.&nbsp;&nbsp;&nbsp;<a href="#ack">Acknowledgments</a></li>
578         <li>9.&nbsp;&nbsp;&nbsp;<a href="#rfc.references">References</a><ul>
579               <li>9.1&nbsp;&nbsp;&nbsp;<a href="#rfc.references.1">Normative References</a></li>
580               <li>9.2&nbsp;&nbsp;&nbsp;<a href="#rfc.references.2">Informative References</a></li>
581            </ul>
582         </li>
583         <li><a href="#rfc.authors">Authors' Addresses</a></li>
584         <li>A.&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.multipart.byteranges">Internet Media Type multipart/byteranges</a></li>
585         <li>B.&nbsp;&nbsp;&nbsp;<a href="#compatibility">Compatibility with Previous Versions</a><ul>
586               <li>B.1&nbsp;&nbsp;&nbsp;<a href="#changes.from.rfc.2616">Changes from RFC 2616</a></li>
587            </ul>
588         </li>
589         <li>C.&nbsp;&nbsp;&nbsp;<a href="#collected.abnf">Collected ABNF</a></li>
590         <li>D.&nbsp;&nbsp;&nbsp;<a href="#change.log">Change Log (to be removed by RFC Editor before publication)</a><ul>
591               <li>D.1&nbsp;&nbsp;&nbsp;<a href="#rfc.section.D.1">Since RFC 2616</a></li>
592               <li>D.2&nbsp;&nbsp;&nbsp;<a href="#rfc.section.D.2">Since draft-ietf-httpbis-p5-range-00</a></li>
593               <li>D.3&nbsp;&nbsp;&nbsp;<a href="#rfc.section.D.3">Since draft-ietf-httpbis-p5-range-01</a></li>
594               <li>D.4&nbsp;&nbsp;&nbsp;<a href="#changes.since.02">Since draft-ietf-httpbis-p5-range-02</a></li>
595               <li>D.5&nbsp;&nbsp;&nbsp;<a href="#changes.since.03">Since draft-ietf-httpbis-p5-range-03</a></li>
596               <li>D.6&nbsp;&nbsp;&nbsp;<a href="#changes.since.04">Since draft-ietf-httpbis-p5-range-04</a></li>
597               <li>D.7&nbsp;&nbsp;&nbsp;<a href="#changes.since.05">Since draft-ietf-httpbis-p5-range-05</a></li>
598               <li>D.8&nbsp;&nbsp;&nbsp;<a href="#changes.since.06">Since draft-ietf-httpbis-p5-range-06</a></li>
599               <li>D.9&nbsp;&nbsp;&nbsp;<a href="#changes.since.07">Since draft-ietf-httpbis-p5-range-07</a></li>
600               <li>D.10&nbsp;&nbsp;&nbsp;<a href="#changes.since.08">Since draft-ietf-httpbis-p5-range-08</a></li>
601               <li>D.11&nbsp;&nbsp;&nbsp;<a href="#changes.since.09">Since draft-ietf-httpbis-p5-range-09</a></li>
602               <li>D.12&nbsp;&nbsp;&nbsp;<a href="#changes.since.10">Since draft-ietf-httpbis-p5-range-10</a></li>
603               <li>D.13&nbsp;&nbsp;&nbsp;<a href="#changes.since.11">Since draft-ietf-httpbis-p5-range-11</a></li>
604               <li>D.14&nbsp;&nbsp;&nbsp;<a href="#changes.since.12">Since draft-ietf-httpbis-p5-range-12</a></li>
605               <li>D.15&nbsp;&nbsp;&nbsp;<a href="#changes.since.13">Since draft-ietf-httpbis-p5-range-13</a></li>
606               <li>D.16&nbsp;&nbsp;&nbsp;<a href="#changes.since.14">Since draft-ietf-httpbis-p5-range-14</a></li>
607               <li>D.17&nbsp;&nbsp;&nbsp;<a href="#changes.since.15">Since draft-ietf-httpbis-p5-range-15</a></li>
608            </ul>
609         </li>
610         <li><a href="#rfc.index">Index</a></li>
611      </ul>
612      <h1 id="rfc.section.1" class="np"><a href="#rfc.section.1">1.</a>&nbsp;<a id="introduction" href="#introduction">Introduction</a></h1>
613      <p id="rfc.section.1.p.1">HTTP clients often encounter interrupted data transfers as a result of cancelled requests or dropped connections. When a cache
614         has stored a partial representation, it is desirable to request the remainder of that representation in a subsequent request
615         rather than transfer the entire representation. There are also a number of Web applications that benefit from being able to
616         request only a subset of a larger representation, such as a single page of a very large document or only part of an image
617         to be rendered by a device with limited local storage.
618      </p>
619      <p id="rfc.section.1.p.2">This document defines HTTP/1.1 range requests, partial responses, and the multipart/byteranges media type. The protocol for
620         range requests is an <em class="bcp14">OPTIONAL</em> feature of HTTP, designed so resources or recipients that do not implement this feature can respond as if it is a normal GET
621         request without impacting interoperability. Partial responses are indicated by a distinct status code to not be mistaken for
622         full responses by intermediate caches that might not implement the feature.
623      </p>
624      <p id="rfc.section.1.p.3">Although the HTTP range request mechanism is designed to allow for extensible range types, this specification only defines
625         requests for byte ranges.
626      </p>
627      <h2 id="rfc.section.1.1"><a href="#rfc.section.1.1">1.1</a>&nbsp;<a id="intro.requirements" href="#intro.requirements">Requirements</a></h2>
628      <p id="rfc.section.1.1.p.1">The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL"
629         in this document are to be interpreted as described in <a href="#RFC2119" id="rfc.xref.RFC2119.1"><cite title="Key words for use in RFCs to Indicate Requirement Levels">[RFC2119]</cite></a>.
630      </p>
631      <p id="rfc.section.1.1.p.2">An implementation is not compliant if it fails to satisfy one or more of the "MUST" or "REQUIRED" level requirements for the
632         protocols it implements. An implementation that satisfies all the "MUST" or "REQUIRED" level and all the "SHOULD" level requirements
633         for its protocols is said to be "unconditionally compliant"; one that satisfies all the "MUST" level requirements but not
634         all the "SHOULD" level requirements for its protocols is said to be "conditionally compliant".
635      </p>
636      <h2 id="rfc.section.1.2"><a href="#rfc.section.1.2">1.2</a>&nbsp;<a id="notation" href="#notation">Syntax Notation</a></h2>
637      <p id="rfc.section.1.2.p.1">This specification uses the ABNF syntax defined in <a href="p1-messaging.html#notation" title="Syntax Notation">Section 1.2</a> of <a href="#Part1" id="rfc.xref.Part1.1"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a> (which extends the syntax defined in <a href="#RFC5234" id="rfc.xref.RFC5234.1"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a> with a list rule). <a href="#collected.abnf" title="Collected ABNF">Appendix&nbsp;C</a> shows the collected ABNF, with the list rule expanded.
638      </p>
639      <p id="rfc.section.1.2.p.2">The following core rules are included by reference, as defined in <a href="#RFC5234" id="rfc.xref.RFC5234.2"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>, <a href="http://tools.ietf.org/html/rfc5234#appendix-B.1">Appendix B.1</a>: ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double quote), HEXDIG
640         (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any 8-bit sequence of data), SP (space), VCHAR (any visible USASCII character),
641         and WSP (whitespace).
642      </p>
643      <h3 id="rfc.section.1.2.1"><a href="#rfc.section.1.2.1">1.2.1</a>&nbsp;<a id="core.rules" href="#core.rules">Core Rules</a></h3>
644      <p id="rfc.section.1.2.1.p.1">The core rules below are defined in <a href="p1-messaging.html#basic.rules" title="Basic Rules">Section 1.2.2</a> of <a href="#Part1" id="rfc.xref.Part1.2"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>:
645      </p>
646      <div id="rfc.figure.u.1"></div><pre class="inline">  <a href="#core.rules" class="smpl">token</a>      = &lt;token, defined in <a href="#Part1" id="rfc.xref.Part1.3"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#basic.rules" title="Basic Rules">Section 1.2.2</a>&gt;
647  <a href="#core.rules" class="smpl">OWS</a>        = &lt;OWS, defined in <a href="#Part1" id="rfc.xref.Part1.4"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#basic.rules" title="Basic Rules">Section 1.2.2</a>&gt;
648</pre><h3 id="rfc.section.1.2.2"><a href="#rfc.section.1.2.2">1.2.2</a>&nbsp;<a id="abnf.dependencies" href="#abnf.dependencies">ABNF Rules defined in other Parts of the Specification</a></h3>
649      <p id="rfc.section.1.2.2.p.1">The ABNF rules below are defined in other parts:</p>
650      <div id="rfc.figure.u.2"></div><pre class="inline">  <a href="#abnf.dependencies" class="smpl">HTTP-date</a>  = &lt;HTTP-date, defined in <a href="#Part1" id="rfc.xref.Part1.5"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#date.time.formats.full.date" title="Date/Time Formats: Full Date">Section 6.1</a>&gt;
651</pre><div id="rfc.figure.u.3"></div><pre class="inline">  <a href="#abnf.dependencies" class="smpl">entity-tag</a> = &lt;entity-tag, defined in <a href="#Part4" id="rfc.xref.Part4.1"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>, <a href="p4-conditional.html#header.etag" title="ETag">Section 2.2</a>&gt;
652</pre><h1 id="rfc.section.2"><a href="#rfc.section.2">2.</a>&nbsp;<a id="range.units" href="#range.units">Range Units</a></h1>
653      <p id="rfc.section.2.p.1">HTTP/1.1 allows a client to request that only part (a range) of the representation be included within the response. HTTP/1.1
654         uses range units in the Range (<a href="#header.range" id="rfc.xref.header.range.1" title="Range">Section&nbsp;5.4</a>) and Content-Range (<a href="#header.content-range" id="rfc.xref.header.content-range.1" title="Content-Range">Section&nbsp;5.2</a>) header fields. A representation can be broken down into subranges according to various structural units.
655      </p>
656      <div id="rfc.figure.u.4"></div><pre class="inline"><span id="rfc.iref.g.1"></span><span id="rfc.iref.g.2"></span><span id="rfc.iref.g.3"></span>  <a href="#range.units" class="smpl">range-unit</a>       = <a href="#range.units" class="smpl">bytes-unit</a> / <a href="#range.units" class="smpl">other-range-unit</a>
657  <a href="#range.units" class="smpl">bytes-unit</a>       = "bytes"
658  <a href="#range.units" class="smpl">other-range-unit</a> = <a href="#core.rules" class="smpl">token</a>
659</pre><p id="rfc.section.2.p.3">HTTP/1.1 has been designed to allow implementations of applications that do not depend on knowledge of ranges. The only range
660         unit defined by HTTP/1.1 is "bytes". Additional specifiers can be defined as described in <a href="#range.specifier.registry" title="Range Specifier Registry">Section&nbsp;2.1</a>.
661      </p>
662      <p id="rfc.section.2.p.4">If a range unit is not understood in a request, a server <em class="bcp14">MUST</em> ignore the whole Range header field (<a href="#header.range" id="rfc.xref.header.range.2" title="Range">Section&nbsp;5.4</a>). If a range unit is not understood in a response, an intermediary <em class="bcp14">SHOULD</em> pass the response to the client; a client <em class="bcp14">MUST</em> fail.
663      </p>
664      <h2 id="rfc.section.2.1"><a href="#rfc.section.2.1">2.1</a>&nbsp;<a id="range.specifier.registry" href="#range.specifier.registry">Range Specifier Registry</a></h2>
665      <p id="rfc.section.2.1.p.1">The HTTP Range Specifier Registry defines the name space for the range specifier names.</p>
666      <p id="rfc.section.2.1.p.2">Registrations <em class="bcp14">MUST</em> include the following fields:
667      </p>
668      <ul>
669         <li>Name</li>
670         <li>Description</li>
671         <li>Pointer to specification text</li>
672      </ul>
673      <p id="rfc.section.2.1.p.3">Values to be added to this name space are subject to IETF review (<a href="#RFC5226" id="rfc.xref.RFC5226.1"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>).
674      </p>
675      <p id="rfc.section.2.1.p.4">The registry itself is maintained at &lt;<a href="http://www.iana.org/assignments/http-range-specifiers">http://www.iana.org/assignments/http-range-specifiers</a>&gt;.
676      </p>
677      <h1 id="rfc.section.3"><a href="#rfc.section.3">3.</a>&nbsp;<a id="status.code.definitions" href="#status.code.definitions">Status Code Definitions</a></h1>
678      <div id="rfc.iref.3"></div>
679      <div id="rfc.iref.s.1"></div>
680      <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a id="status.206" href="#status.206">206 Partial Content</a></h2>
681      <p id="rfc.section.3.1.p.1">The server has fulfilled the partial GET request for the resource. The request <em class="bcp14">MUST</em> have included a Range header field (<a href="#header.range" id="rfc.xref.header.range.3" title="Range">Section&nbsp;5.4</a>) indicating the desired range, and <em class="bcp14">MAY</em> have included an If-Range header field (<a href="#header.if-range" id="rfc.xref.header.if-range.1" title="If-Range">Section&nbsp;5.3</a>) to make the request conditional.
682      </p>
683      <p id="rfc.section.3.1.p.2">The response <em class="bcp14">MUST</em> include the following header fields:
684      </p>
685      <ul>
686         <li>Either a Content-Range header field (<a href="#header.content-range" id="rfc.xref.header.content-range.2" title="Content-Range">Section&nbsp;5.2</a>) indicating the range included with this response, or a multipart/byteranges Content-Type including Content-Range fields
687            for each part. If a Content-Length header field is present in the response, its value <em class="bcp14">MUST</em> match the actual number of octets transmitted in the message-body.
688         </li>
689         <li>Date</li>
690         <li>Cache-Control, ETag, Expires, Content-Location, Last-Modified, and/or Vary, if the header field would have been sent in a
691            200 response to the same request
692         </li>
693      </ul>
694      <p id="rfc.section.3.1.p.3">If the 206 response is the result of an If-Range request, the response <em class="bcp14">SHOULD NOT</em> include other representation header fields. Otherwise, the response <em class="bcp14">MUST</em> include all of the representation header fields that would have been returned with a 200 (OK) response to the same request.
695      </p>
696      <p id="rfc.section.3.1.p.4">A cache <em class="bcp14">MUST NOT</em> combine a 206 response with other previously cached content if the ETag or Last-Modified header fields do not match exactly,
697         see <a href="#combining.byte.ranges" title="Combining Ranges">Section&nbsp;4</a>.
698      </p>
699      <p id="rfc.section.3.1.p.5">A cache that does not support the Range and Content-Range header fields <em class="bcp14">MUST NOT</em> cache 206 (Partial Content) responses. Furthermore, if a response uses a range unit that is not understood by the cache, then
700         it <em class="bcp14">MUST NOT</em> be cached either.
701      </p>
702      <div id="rfc.iref.4"></div>
703      <div id="rfc.iref.s.2"></div>
704      <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a>&nbsp;<a id="status.416" href="#status.416">416 Requested Range Not Satisfiable</a></h2>
705      <p id="rfc.section.3.2.p.1">A server <em class="bcp14">SHOULD</em> return a response with this status code if a request included a Range header field (<a href="#header.range" id="rfc.xref.header.range.4" title="Range">Section&nbsp;5.4</a>), and none of the ranges-specifier values in this field overlap the current extent of the selected resource, and the request
706         did not include an If-Range header field (<a href="#header.if-range" id="rfc.xref.header.if-range.2" title="If-Range">Section&nbsp;5.3</a>). (For byte-ranges, this means that the first-byte-pos of all of the byte-range-spec values were greater than the current
707         length of the selected resource.)
708      </p>
709      <p id="rfc.section.3.2.p.2">When this status code is returned for a byte-range request, the response <em class="bcp14">SHOULD</em> include a Content-Range header field specifying the current length of the representation (see <a href="#header.content-range" id="rfc.xref.header.content-range.3" title="Content-Range">Section&nbsp;5.2</a>). This response <em class="bcp14">MUST NOT</em> use the multipart/byteranges content-type.
710      </p>
711      <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="combining.byte.ranges" href="#combining.byte.ranges">Combining Ranges</a></h1>
712      <p id="rfc.section.4.p.1">A response might transfer only a subrange of a representation, either because the request included one or more Range specifications,
713         or because a connection closed prematurely. After several such transfers, a cache might have received several ranges of the
714         same representation.
715      </p>
716      <p id="rfc.section.4.p.2">If a cache has a stored non-empty set of subranges for a representation, and an incoming response transfers another subrange,
717         the cache <em class="bcp14">MAY</em> combine the new subrange with the existing set if both the following conditions are met:
718      </p>
719      <ul>
720         <li>Both the incoming response and the cache entry have a cache validator.</li>
721         <li>The two cache validators match using the strong comparison function (see <a href="p4-conditional.html#weak.and.strong.validators" title="Weak versus Strong">Section 2.2.2</a> of <a href="#Part4" id="rfc.xref.Part4.2"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>).
722         </li>
723      </ul>
724      <p id="rfc.section.4.p.3">If either requirement is not met, the cache <em class="bcp14">MUST</em> use only the most recent partial response (based on the Date values transmitted with every response, and using the incoming
725         response if these values are equal or missing), and <em class="bcp14">MUST</em> discard the other partial information.
726      </p>
727      <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="header.fields" href="#header.fields">Header Field Definitions</a></h1>
728      <p id="rfc.section.5.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to range requests and partial responses.</p>
729      <div id="rfc.iref.a.1"></div>
730      <div id="rfc.iref.h.1"></div>
731      <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a>&nbsp;<a id="header.accept-ranges" href="#header.accept-ranges">Accept-Ranges</a></h2>
732      <p id="rfc.section.5.1.p.1">The "Accept-Ranges" header field allows a resource to indicate its acceptance of range requests.</p>
733      <div id="rfc.figure.u.5"></div><pre class="inline"><span id="rfc.iref.g.4"></span><span id="rfc.iref.g.5"></span>  <a href="#header.accept-ranges" class="smpl">Accept-Ranges</a>     = <a href="#header.accept-ranges" class="smpl">acceptable-ranges</a>
734  <a href="#header.accept-ranges" class="smpl">acceptable-ranges</a> = 1#<a href="#range.units" class="smpl">range-unit</a> / "none"
735</pre><p id="rfc.section.5.1.p.3">Origin servers that accept byte-range requests <em class="bcp14">MAY</em> send
736      </p>
737      <div id="rfc.figure.u.6"></div><pre class="text">  Accept-Ranges: bytes
738</pre><p id="rfc.section.5.1.p.5">but are not required to do so. Clients <em class="bcp14">MAY</em> generate range requests without having received this header field for the resource involved. Range units are defined in <a href="#range.units" title="Range Units">Section&nbsp;2</a>.
739      </p>
740      <p id="rfc.section.5.1.p.6">Servers that do not accept any kind of range request for a resource <em class="bcp14">MAY</em> send
741      </p>
742      <div id="rfc.figure.u.7"></div><pre class="text">  Accept-Ranges: none
743</pre><p id="rfc.section.5.1.p.8">to advise the client not to attempt a range request.</p>
744      <div id="rfc.iref.c.1"></div>
745      <div id="rfc.iref.h.2"></div>
746      <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</a>&nbsp;<a id="header.content-range" href="#header.content-range">Content-Range</a></h2>
747      <p id="rfc.section.5.2.p.1">The "Content-Range" header field is sent with a partial representation to specify where in the full representation the payload
748         body is intended to be applied.
749      </p>
750      <p id="rfc.section.5.2.p.2">Range units are defined in <a href="#range.units" title="Range Units">Section&nbsp;2</a>.
751      </p>
752      <div id="rfc.figure.u.8"></div><pre class="inline"><span id="rfc.iref.g.6"></span><span id="rfc.iref.g.7"></span><span id="rfc.iref.g.8"></span><span id="rfc.iref.g.9"></span><span id="rfc.iref.g.10"></span>  <a href="#header.content-range" class="smpl">Content-Range</a> = <a href="#header.content-range" class="smpl">content-range-spec</a>
753 
754  <a href="#header.content-range" class="smpl">content-range-spec</a>      = <a href="#header.content-range" class="smpl">byte-content-range-spec</a>
755                          / <a href="#header.content-range" class="smpl">other-content-range-spec</a>
756  <a href="#header.content-range" class="smpl">byte-content-range-spec</a> = <a href="#range.units" class="smpl">bytes-unit</a> <a href="#notation" class="smpl">SP</a>
757                            <a href="#header.content-range" class="smpl">byte-range-resp-spec</a> "/"
758                            ( <a href="#header.content-range" class="smpl">instance-length</a> / "*" )
759 
760  <a href="#header.content-range" class="smpl">byte-range-resp-spec</a>    = (<a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> "-" <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a>)
761                          / "*"
762                         
763  <a href="#header.content-range" class="smpl">instance-length</a>         = 1*<a href="#notation" class="smpl">DIGIT</a>
764 
765  <a href="#header.content-range" class="smpl">other-content-range-spec</a> = <a href="#range.units" class="smpl">other-range-unit</a> <a href="#notation" class="smpl">SP</a>
766                             <a href="#header.content-range" class="smpl">other-range-resp-spec</a>
767  <a href="#header.content-range" class="smpl">other-range-resp-spec</a>    = *<a href="#notation" class="smpl">CHAR</a>
768</pre><p id="rfc.section.5.2.p.4">The header field <em class="bcp14">SHOULD</em> indicate the total length of the full representation, unless this length is unknown or difficult to determine. The asterisk
769         "*" character means that the instance-length is unknown at the time when the response was generated.
770      </p>
771      <p id="rfc.section.5.2.p.5">Unlike byte-ranges-specifier values (see <a href="#byte.ranges" title="Byte Ranges">Section&nbsp;5.4.1</a>), a byte-range-resp-spec <em class="bcp14">MUST</em> only specify one range, and <em class="bcp14">MUST</em> contain absolute byte positions for both the first and last byte of the range.
772      </p>
773      <p id="rfc.section.5.2.p.6">A byte-content-range-spec with a byte-range-resp-spec whose last-byte-pos value is less than its first-byte-pos value, or
774         whose instance-length value is less than or equal to its last-byte-pos value, is invalid. The recipient of an invalid byte-content-range-spec <em class="bcp14">MUST</em> ignore it and any content transferred along with it.
775      </p>
776      <p id="rfc.section.5.2.p.7">In the case of a byte range request: A server sending a response with status code 416 (Requested range not satisfiable) <em class="bcp14">SHOULD</em> include a Content-Range field with a byte-range-resp-spec of "*". The instance-length specifies the current length of the
777         selected resource. A response with status code 206 (Partial Content) <em class="bcp14">MUST NOT</em> include a Content-Range field with a byte-range-resp-spec of "*".
778      </p>
779      <p id="rfc.section.5.2.p.8">Examples of byte-content-range-spec values, assuming that the representation contains a total of 1234 bytes: </p>
780      <ul>
781         <li>The first 500 bytes:
782            <div id="rfc.figure.u.9"></div><pre class="text">  bytes 0-499/1234
783</pre> </li>
784         <li>The second 500 bytes:
785            <div id="rfc.figure.u.10"></div><pre class="text">  bytes 500-999/1234
786</pre> </li>
787         <li>All except for the first 500 bytes:
788            <div id="rfc.figure.u.11"></div><pre class="text">  bytes 500-1233/1234
789</pre> </li>
790         <li>The last 500 bytes:
791            <div id="rfc.figure.u.12"></div><pre class="text">  bytes 734-1233/1234
792</pre> </li>
793      </ul>
794      <p id="rfc.section.5.2.p.9">When an HTTP message includes the content of a single range (for example, a response to a request for a single range, or to
795         a request for a set of ranges that overlap without any holes), this content is transmitted with a Content-Range header field,
796         and a Content-Length header field showing the number of bytes actually transferred. For example,
797      </p>
798      <div id="rfc.figure.u.13"></div><pre class="text">  HTTP/1.1 206 Partial Content
799  Date: Wed, 15 Nov 1995 06:25:24 GMT
800  Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT
801  Content-Range: bytes 21010-47021/47022
802  Content-Length: 26012
803  Content-Type: image/gif
804</pre><p id="rfc.section.5.2.p.11">When an HTTP message includes the content of multiple ranges (for example, a response to a request for multiple non-overlapping
805         ranges), these are transmitted as a multipart message. The multipart media type used for this purpose is "multipart/byteranges"
806         as defined in <a href="#internet.media.type.multipart.byteranges" title="Internet Media Type multipart/byteranges">Appendix&nbsp;A</a>.
807      </p>
808      <p id="rfc.section.5.2.p.12">A response to a request for a single range <em class="bcp14">MUST NOT</em> be sent using the multipart/byteranges media type. A response to a request for multiple ranges, whose result is a single range, <em class="bcp14">MAY</em> be sent as a multipart/byteranges media type with one part. A client that cannot decode a multipart/byteranges message <em class="bcp14">MUST NOT</em> ask for multiple ranges in a single request.
809      </p>
810      <p id="rfc.section.5.2.p.13">When a client requests multiple ranges in one request, the server <em class="bcp14">SHOULD</em> return them in the order that they appeared in the request.
811      </p>
812      <p id="rfc.section.5.2.p.14">If the server ignores a byte-range-spec because it is syntactically invalid, the server <em class="bcp14">SHOULD</em> treat the request as if the invalid Range header field did not exist. (Normally, this means return a 200 response containing
813         the full representation).
814      </p>
815      <p id="rfc.section.5.2.p.15">If the server receives a request (other than one including an If-Range header field) with an unsatisfiable Range header field
816         (that is, all of whose byte-range-spec values have a first-byte-pos value greater than the current length of the selected
817         resource), it <em class="bcp14">SHOULD</em> return a response code of 416 (Requested range not satisfiable) (<a href="#status.416" id="rfc.xref.status.416.1" title="416 Requested Range Not Satisfiable">Section&nbsp;3.2</a>).
818      </p>
819      <div class="note" id="rfc.section.5.2.p.16"> 
820         <p> <b>Note:</b> Clients cannot depend on servers to send a 416 (Requested range not satisfiable) response instead of a 200 (OK) response for
821            an unsatisfiable Range header field, since not all servers implement this header field.
822         </p> 
823      </div>
824      <div id="rfc.iref.i.1"></div>
825      <div id="rfc.iref.h.3"></div>
826      <h2 id="rfc.section.5.3"><a href="#rfc.section.5.3">5.3</a>&nbsp;<a id="header.if-range" href="#header.if-range">If-Range</a></h2>
827      <p id="rfc.section.5.3.p.1">If a client has a partial copy of a representation in its cache, and wishes to have an up-to-date copy of the entire representation
828         in its cache, it could use the Range header field with a conditional GET (using either or both of If-Unmodified-Since and
829         If-Match.) However, if the condition fails because the representation has been modified, the client would then have to make
830         a second request to obtain the entire current representation.
831      </p>
832      <p id="rfc.section.5.3.p.2">The "If-Range" header field allows a client to "short-circuit" the second request. Informally, its meaning is "if the representation
833         is unchanged, send me the part(s) that I am missing; otherwise, send me the entire new representation".
834      </p>
835      <div id="rfc.figure.u.14"></div><pre class="inline"><span id="rfc.iref.g.11"></span>  <a href="#header.if-range" class="smpl">If-Range</a> = <a href="#abnf.dependencies" class="smpl">entity-tag</a> / <a href="#abnf.dependencies" class="smpl">HTTP-date</a>
836</pre><p id="rfc.section.5.3.p.4">Only a strong validator (<a href="p4-conditional.html#weak.and.strong.validators" title="Weak versus Strong">Section 2.2.2</a> of <a href="#Part4" id="rfc.xref.Part4.3"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>) is usable for range retrieval, since otherwise the client might end up with an internally inconsistent representation. Clients <em class="bcp14">MUST NOT</em> use weak validators in range requests. A cache or origin server receiving a conditional range request <em class="bcp14">MUST</em> use the strong comparison function to evaluate the condition.
837      </p>
838      <p id="rfc.section.5.3.p.5">If the client has no entity-tag for a representation, but does have a Last-Modified date, it <em class="bcp14">MAY</em> use that date in an If-Range header field. (The server can distinguish between a valid HTTP-date and any form of entity-tag
839         by examining no more than two characters.) The If-Range header field <em class="bcp14">SHOULD</em> only be used together with a Range header field, and <em class="bcp14">MUST</em> be ignored if the request does not include a Range header field, or if the server does not support the sub-range operation.
840      </p>
841      <p id="rfc.section.5.3.p.6">If a client wishes to perform a sub-range retrieval on a value for which it has only a Last-Modified time and no opaque validator,
842         it <em class="bcp14">MAY</em> do this only if the Last-Modified time is strong in the sense described in <a href="p4-conditional.html#lastmod.comparison" title="Comparison">Section 2.1.2</a> of <a href="#Part4" id="rfc.xref.Part4.4"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>.
843      </p>
844      <p id="rfc.section.5.3.p.7">If the entity-tag given in the If-Range header field matches the current cache validator for the representation, then the
845         server <em class="bcp14">SHOULD</em> provide the specified sub-range of the representation using a 206 (Partial Content) response. If the cache validator does
846         not match, then the server <em class="bcp14">SHOULD</em> return the entire representation using a 200 (OK) response.
847      </p>
848      <div id="rfc.iref.r.1"></div>
849      <div id="rfc.iref.h.4"></div>
850      <h2 id="rfc.section.5.4"><a href="#rfc.section.5.4">5.4</a>&nbsp;<a id="header.range" href="#header.range">Range</a></h2>
851      <h3 id="rfc.section.5.4.1"><a href="#rfc.section.5.4.1">5.4.1</a>&nbsp;<a id="byte.ranges" href="#byte.ranges">Byte Ranges</a></h3>
852      <p id="rfc.section.5.4.1.p.1">Since all HTTP representations are transferred as sequences of bytes, the concept of a byte range is meaningful for any HTTP
853         representation. (However, not all clients and servers need to support byte-range operations.)
854      </p>
855      <p id="rfc.section.5.4.1.p.2">Byte range specifications in HTTP apply to the sequence of bytes in the representation body (not necessarily the same as the
856         message-body).
857      </p>
858      <div id="rule.ranges-specifier">
859         <p id="rfc.section.5.4.1.p.3">                A byte range operation <em class="bcp14">MAY</em> specify a single range of bytes, or a set of ranges within a single representation.
860         </p>
861      </div>
862      <div id="rfc.figure.u.15"></div><pre class="inline"><span id="rfc.iref.g.12"></span><span id="rfc.iref.g.13"></span><span id="rfc.iref.g.14"></span><span id="rfc.iref.g.15"></span><span id="rfc.iref.g.16"></span><span id="rfc.iref.g.17"></span>  <a href="#rule.ranges-specifier" class="smpl">byte-ranges-specifier</a> = <a href="#range.units" class="smpl">bytes-unit</a> "=" <a href="#rule.ranges-specifier" class="smpl">byte-range-set</a>
863  <a href="#rule.ranges-specifier" class="smpl">byte-range-set</a>  = 1#( <a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> / <a href="#rule.ranges-specifier" class="smpl">suffix-byte-range-spec</a> )
864  <a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> = <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> "-" [ <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> ]
865  <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a>  = 1*<a href="#notation" class="smpl">DIGIT</a>
866  <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a>   = 1*<a href="#notation" class="smpl">DIGIT</a>
867</pre><p id="rfc.section.5.4.1.p.5">The first-byte-pos value in a byte-range-spec gives the byte-offset of the first byte in a range. The last-byte-pos value
868         gives the byte-offset of the last byte in the range; that is, the byte positions specified are inclusive. Byte offsets start
869         at zero.
870      </p>
871      <p id="rfc.section.5.4.1.p.6">If the last-byte-pos value is present, it <em class="bcp14">MUST</em> be greater than or equal to the first-byte-pos in that byte-range-spec, or the byte-range-spec is syntactically invalid. The
872         recipient of a byte-range-set that includes one or more syntactically invalid byte-range-spec values <em class="bcp14">MUST</em> ignore the header field that includes that byte-range-set.
873      </p>
874      <p id="rfc.section.5.4.1.p.7">If the last-byte-pos value is absent, or if the value is greater than or equal to the current length of the representation
875         body, last-byte-pos is taken to be equal to one less than the current length of the representation in bytes.
876      </p>
877      <p id="rfc.section.5.4.1.p.8">By its choice of last-byte-pos, a client can limit the number of bytes retrieved without knowing the size of the representation.</p>
878      <div id="rfc.figure.u.16"></div><pre class="inline"><span id="rfc.iref.g.18"></span><span id="rfc.iref.g.19"></span>  <a href="#rule.ranges-specifier" class="smpl">suffix-byte-range-spec</a> = "-" <a href="#rule.ranges-specifier" class="smpl">suffix-length</a>
879  <a href="#rule.ranges-specifier" class="smpl">suffix-length</a> = 1*<a href="#notation" class="smpl">DIGIT</a>
880</pre><p id="rfc.section.5.4.1.p.10">A suffix-byte-range-spec is used to specify the suffix of the representation body, of a length given by the suffix-length
881         value. (That is, this form specifies the last N bytes of a representation.) If the representation is shorter than the specified
882         suffix-length, the entire representation is used.
883      </p>
884      <p id="rfc.section.5.4.1.p.11">If a syntactically valid byte-range-set includes at least one byte-range-spec whose first-byte-pos is less than the current
885         length of the representation, or at least one suffix-byte-range-spec with a non-zero suffix-length, then the byte-range-set
886         is satisfiable. Otherwise, the byte-range-set is unsatisfiable. If the byte-range-set is unsatisfiable, the server <em class="bcp14">SHOULD</em> return a response with a 416 (Requested range not satisfiable) status code. Otherwise, the server <em class="bcp14">SHOULD</em> return a response with a 206 (Partial Content) status code containing the satisfiable ranges of the representation.
887      </p>
888      <p id="rfc.section.5.4.1.p.12">Examples of byte-ranges-specifier values (assuming a representation of length 10000): </p>
889      <ul>
890         <li>The first 500 bytes (byte offsets 0-499, inclusive):
891            <div id="rfc.figure.u.17"></div><pre class="text">  bytes=0-499
892</pre> </li>
893         <li>The second 500 bytes (byte offsets 500-999, inclusive):
894            <div id="rfc.figure.u.18"></div><pre class="text">  bytes=500-999
895</pre> </li>
896         <li>The final 500 bytes (byte offsets 9500-9999, inclusive):
897            <div id="rfc.figure.u.19"></div><pre class="text">  bytes=-500
898</pre> Or: <div id="rfc.figure.u.20"></div><pre class="text">  bytes=9500-
899</pre> </li>
900         <li>The first and last bytes only (bytes 0 and 9999):
901            <div id="rfc.figure.u.21"></div><pre class="text">  bytes=0-0,-1
902</pre> </li>
903         <li>Several legal but not canonical specifications of the second 500 bytes (byte offsets 500-999, inclusive):
904            <div id="rfc.figure.u.22"></div><pre class="text">  bytes=500-600,601-999
905  bytes=500-700,601-999
906</pre> </li>
907      </ul>
908      <h3 id="rfc.section.5.4.2"><a href="#rfc.section.5.4.2">5.4.2</a>&nbsp;<a id="range.retrieval.requests" href="#range.retrieval.requests">Range Retrieval Requests</a></h3>
909      <p id="rfc.section.5.4.2.p.1">The "Range" header field defines the GET method (conditional or not) to request one or more sub-ranges of the response representation
910         body, instead of the entire representation body.
911      </p>
912      <div id="rfc.figure.u.23"></div><pre class="inline"><span id="rfc.iref.g.20"></span>  <a href="#range.retrieval.requests" class="smpl">Range</a> = <a href="#rule.ranges-specifier" class="smpl">byte-ranges-specifier</a> / <a href="#range.retrieval.requests" class="smpl">other-ranges-specifier</a>
913  <a href="#range.retrieval.requests" class="smpl">other-ranges-specifier</a> = <a href="#range.units" class="smpl">other-range-unit</a> "=" <a href="#range.retrieval.requests" class="smpl">other-range-set</a>
914  <a href="#range.retrieval.requests" class="smpl">other-range-set</a> = 1*<a href="#notation" class="smpl">CHAR</a>
915</pre><p id="rfc.section.5.4.2.p.3">A server <em class="bcp14">MAY</em> ignore the Range header field. However, HTTP/1.1 origin servers and intermediate caches ought to support byte ranges when
916         possible, since Range supports efficient recovery from partially failed transfers, and supports efficient partial retrieval
917         of large representations.
918      </p>
919      <p id="rfc.section.5.4.2.p.4">If the server supports the Range header field and the specified range or ranges are appropriate for the representation: </p>
920      <ul>
921         <li>The presence of a Range header field in an unconditional GET modifies what is returned if the GET is otherwise successful.
922            In other words, the response carries a status code of 206 (Partial Content) instead of 200 (OK).
923         </li>
924         <li>The presence of a Range header field in a conditional GET (a request using one or both of If-Modified-Since and If-None-Match,
925            or one or both of If-Unmodified-Since and If-Match) modifies what is returned if the GET is otherwise successful and the condition
926            is true. It does not affect the 304 (Not Modified) response returned if the conditional is false.
927         </li>
928      </ul>
929      <p id="rfc.section.5.4.2.p.5">In some cases, it might be more appropriate to use the If-Range header field (see <a href="#header.if-range" id="rfc.xref.header.if-range.3" title="If-Range">Section&nbsp;5.3</a>) in addition to the Range header field.
930      </p>
931      <p id="rfc.section.5.4.2.p.6">If a proxy that supports ranges receives a Range request, forwards the request to an inbound server, and receives an entire
932         representation in reply, it <em class="bcp14">MAY</em> only return the requested range to its client.
933      </p>
934      <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>
935      <h2 id="rfc.section.6.1"><a href="#rfc.section.6.1">6.1</a>&nbsp;<a id="status.code.registration" href="#status.code.registration">Status Code Registration</a></h2>
936      <p id="rfc.section.6.1.p.1">The HTTP Status Code Registry located at &lt;<a href="http://www.iana.org/assignments/http-status-codes">http://www.iana.org/assignments/http-status-codes</a>&gt; shall be updated with the registrations below:
937      </p>
938      <div id="rfc.table.1">
939         <div id="iana.status.code.registration.table"></div>
940         <table class="tt full left" cellpadding="3" cellspacing="0">
941            <thead>
942               <tr>
943                  <th>Value</th>
944                  <th>Description</th>
945                  <th>Reference</th>
946               </tr>
947            </thead>
948            <tbody>
949               <tr>
950                  <td class="left">206</td>
951                  <td class="left">Partial Content</td>
952                  <td class="left"> <a href="#status.206" id="rfc.xref.status.206.1" title="206 Partial Content">Section&nbsp;3.1</a> 
953                  </td>
954               </tr>
955               <tr>
956                  <td class="left">416</td>
957                  <td class="left">Requested Range Not Satisfiable</td>
958                  <td class="left"> <a href="#status.416" id="rfc.xref.status.416.2" title="416 Requested Range Not Satisfiable">Section&nbsp;3.2</a> 
959                  </td>
960               </tr>
961            </tbody>
962         </table>
963      </div>
964      <h2 id="rfc.section.6.2"><a href="#rfc.section.6.2">6.2</a>&nbsp;<a id="header.field.registration" href="#header.field.registration">Header Field Registration</a></h2>
965      <p id="rfc.section.6.2.p.1">The Message Header Field Registry located at &lt;<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>&gt; shall be updated with the permanent registrations below (see <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>):
966      </p>
967      <div id="rfc.table.2">
968         <div id="iana.header.registration.table"></div>
969         <table class="tt full left" cellpadding="3" cellspacing="0">
970            <thead>
971               <tr>
972                  <th>Header Field Name</th>
973                  <th>Protocol</th>
974                  <th>Status</th>
975                  <th>Reference</th>
976               </tr>
977            </thead>
978            <tbody>
979               <tr>
980                  <td class="left">Accept-Ranges</td>
981                  <td class="left">http</td>
982                  <td class="left">standard</td>
983                  <td class="left"> <a href="#header.accept-ranges" id="rfc.xref.header.accept-ranges.1" title="Accept-Ranges">Section&nbsp;5.1</a> 
984                  </td>
985               </tr>
986               <tr>
987                  <td class="left">Content-Range</td>
988                  <td class="left">http</td>
989                  <td class="left">standard</td>
990                  <td class="left"> <a href="#header.content-range" id="rfc.xref.header.content-range.4" title="Content-Range">Section&nbsp;5.2</a> 
991                  </td>
992               </tr>
993               <tr>
994                  <td class="left">If-Range</td>
995                  <td class="left">http</td>
996                  <td class="left">standard</td>
997                  <td class="left"> <a href="#header.if-range" id="rfc.xref.header.if-range.4" title="If-Range">Section&nbsp;5.3</a> 
998                  </td>
999               </tr>
1000               <tr>
1001                  <td class="left">Range</td>
1002                  <td class="left">http</td>
1003                  <td class="left">standard</td>
1004                  <td class="left"> <a href="#header.range" id="rfc.xref.header.range.5" title="Range">Section&nbsp;5.4</a> 
1005                  </td>
1006               </tr>
1007            </tbody>
1008         </table>
1009      </div>
1010      <p id="rfc.section.6.2.p.2">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
1011      <h2 id="rfc.section.6.3"><a href="#rfc.section.6.3">6.3</a>&nbsp;<a id="range.specifier.registration" href="#range.specifier.registration">Range Specifier Registration</a></h2>
1012      <p id="rfc.section.6.3.p.1">The registration procedure for HTTP Range Specifiers is defined by <a href="#range.specifier.registry" title="Range Specifier Registry">Section&nbsp;2.1</a> of this document.
1013      </p>
1014      <p id="rfc.section.6.3.p.2">The HTTP Range Specifier Registry shall be created at &lt;<a href="http://www.iana.org/assignments/http-range-specifiers">http://www.iana.org/assignments/http-range-specifiers</a>&gt; and be populated with the registrations below:
1015      </p>
1016      <div id="rfc.table.3">
1017         <div id="iana.range.specifiers.table"></div>
1018         <table class="tt full left" cellpadding="3" cellspacing="0">
1019            <thead>
1020               <tr>
1021                  <th>Range Specifier Name</th>
1022                  <th>Description</th>
1023                  <th>Reference</th>
1024               </tr>
1025            </thead>
1026            <tbody>
1027               <tr>
1028                  <td class="left">bytes</td>
1029                  <td class="left">a range of octets</td>
1030                  <td class="left">(this specification)</td>
1031               </tr>
1032            </tbody>
1033         </table>
1034      </div>
1035      <p id="rfc.section.6.3.p.3">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
1036      <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>
1037      <p id="rfc.section.7.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1
1038         as described by this document. The discussion does not include definitive solutions to the problems revealed, though it does
1039         make some suggestions for reducing security risks.
1040      </p>
1041      <h2 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1</a>&nbsp;<a id="overlapping.ranges" href="#overlapping.ranges">Overlapping Ranges</a></h2>
1042      <p id="rfc.section.7.1.p.1">Range requests containing overlapping ranges may lead to the situation where a server is sending far more data than the size
1043         of the complete resource representation.
1044      </p>
1045      <h1 id="rfc.section.8"><a href="#rfc.section.8">8.</a>&nbsp;<a id="ack" href="#ack">Acknowledgments</a></h1>
1046      <p id="rfc.section.8.p.1">Most of the specification of ranges is based on work originally done by Ari Luotonen and John Franks, with additional input
1047         from Steve Zilles, Daniel W. Connolly, Roy T. Fielding, Jim Gettys, Martin Hamilton, Koen Holtman, Shel Kaplan, Paul Leach,
1048         Alex Lopez-Ortiz, Larry Masinter, Jeff Mogul, Lou Montulli, David W. Morris, Luigi Rizzo, and Bill Weihl.
1049      </p>
1050      <h1 id="rfc.references"><a id="rfc.section.9" href="#rfc.section.9">9.</a> References
1051      </h1>
1052      <h2 id="rfc.references.1"><a href="#rfc.section.9.1" id="rfc.section.9.1">9.1</a> Normative References
1053      </h2>
1054      <table>         
1055         <tr>
1056            <td class="reference"><b id="Part1">[Part1]</b></td>
1057            <td class="top"><a href="mailto:fielding@gbiv.com" title="Adobe Systems Incorporated">Fielding, R., Ed.</a>, <a href="mailto:jg@freedesktop.org" title="Alcatel-Lucent Bell Labs">Gettys, J.</a>, <a href="mailto:JeffMogul@acm.org" title="Hewlett-Packard Company">Mogul, J.</a>, <a href="mailto:henrikn@microsoft.com" title="Microsoft Corporation">Frystyk, H.</a>, <a href="mailto:LMM@acm.org" title="Adobe Systems Incorporated">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, <a href="mailto:timbl@w3.org" title="World Wide Web Consortium">Berners-Lee, T.</a>, <a href="mailto:ylafon@w3.org" title="World Wide Web Consortium">Lafon, Y., Ed.</a>, and <a href="mailto:julian.reschke@greenbytes.de" title="greenbytes GmbH">J. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-latest">HTTP/1.1, part 1: URIs, Connections, and Message Parsing</a>”, Internet-Draft&nbsp;draft-ietf-httpbis-p1-messaging-latest (work in progress), July&nbsp;2011.
1058            </td>
1059         </tr>
1060         <tr>
1061            <td class="reference"><b id="Part4">[Part4]</b></td>
1062            <td class="top"><a href="mailto:fielding@gbiv.com" title="Adobe Systems Incorporated">Fielding, R., Ed.</a>, <a href="mailto:jg@freedesktop.org" title="Alcatel-Lucent Bell Labs">Gettys, J.</a>, <a href="mailto:JeffMogul@acm.org" title="Hewlett-Packard Company">Mogul, J.</a>, <a href="mailto:henrikn@microsoft.com" title="Microsoft Corporation">Frystyk, H.</a>, <a href="mailto:LMM@acm.org" title="Adobe Systems Incorporated">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, <a href="mailto:timbl@w3.org" title="World Wide Web Consortium">Berners-Lee, T.</a>, <a href="mailto:ylafon@w3.org" title="World Wide Web Consortium">Lafon, Y., Ed.</a>, and <a href="mailto:julian.reschke@greenbytes.de" title="greenbytes GmbH">J. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-latest">HTTP/1.1, part 4: Conditional Requests</a>”, Internet-Draft&nbsp;draft-ietf-httpbis-p4-conditional-latest (work in progress), July&nbsp;2011.
1063            </td>
1064         </tr>
1065         <tr>
1066            <td class="reference"><b id="RFC2046">[RFC2046]</b></td>
1067            <td class="top"><a href="mailto:ned@innosoft.com" title="Innosoft International, Inc.">Freed, N.</a> and <a href="mailto:nsb@nsb.fv.com" title="First Virtual Holdings">N. Borenstein</a>, “<a href="http://tools.ietf.org/html/rfc2046">Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types</a>”, RFC&nbsp;2046, November&nbsp;1996.
1068            </td>
1069         </tr>
1070         <tr>
1071            <td class="reference"><b id="RFC2119">[RFC2119]</b></td>
1072            <td class="top"><a href="mailto:sob@harvard.edu" title="Harvard University">Bradner, S.</a>, “<a href="http://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>”, BCP&nbsp;14, RFC&nbsp;2119, March&nbsp;1997.
1073            </td>
1074         </tr>
1075         <tr>
1076            <td class="reference"><b id="RFC5234">[RFC5234]</b></td>
1077            <td class="top"><a href="mailto:dcrocker@bbiw.net" title="Brandenburg InternetWorking">Crocker, D., Ed.</a> and <a href="mailto:paul.overell@thus.net" title="THUS plc.">P. Overell</a>, “<a href="http://tools.ietf.org/html/rfc5234">Augmented BNF for Syntax Specifications: ABNF</a>”, STD&nbsp;68, RFC&nbsp;5234, January&nbsp;2008.
1078            </td>
1079         </tr>
1080      </table>
1081      <h2 id="rfc.references.2"><a href="#rfc.section.9.2" id="rfc.section.9.2">9.2</a> Informative References
1082      </h2>
1083      <table>       
1084         <tr>
1085            <td class="reference"><b id="RFC2616">[RFC2616]</b></td>
1086            <td class="top"><a href="mailto:fielding@ics.uci.edu" title="University of California, Irvine">Fielding, R.</a>, <a href="mailto:jg@w3.org" title="W3C">Gettys, J.</a>, <a href="mailto:mogul@wrl.dec.com" title="Compaq Computer Corporation">Mogul, J.</a>, <a href="mailto:frystyk@w3.org" title="MIT Laboratory for Computer Science">Frystyk, H.</a>, <a href="mailto:masinter@parc.xerox.com" title="Xerox Corporation">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, and <a href="mailto:timbl@w3.org" title="W3C">T. Berners-Lee</a>, “<a href="http://tools.ietf.org/html/rfc2616">Hypertext Transfer Protocol -- HTTP/1.1</a>”, RFC&nbsp;2616, June&nbsp;1999.
1087            </td>
1088         </tr>
1089         <tr>
1090            <td class="reference"><b id="RFC3864">[RFC3864]</b></td>
1091            <td class="top"><a href="mailto:GK-IETF@ninebynine.org" title="Nine by Nine">Klyne, G.</a>, <a href="mailto:mnot@pobox.com" title="BEA Systems">Nottingham, M.</a>, and <a href="mailto:JeffMogul@acm.org" title="HP Labs">J. Mogul</a>, “<a href="http://tools.ietf.org/html/rfc3864">Registration Procedures for Message Header Fields</a>”, BCP&nbsp;90, RFC&nbsp;3864, September&nbsp;2004.
1092            </td>
1093         </tr>
1094         <tr>
1095            <td class="reference"><b id="RFC4288">[RFC4288]</b></td>
1096            <td class="top"><a href="mailto:ned.freed@mrochek.com" title="Sun Microsystems">Freed, N.</a> and <a href="mailto:klensin+ietf@jck.com">J. Klensin</a>, “<a href="http://tools.ietf.org/html/rfc4288">Media Type Specifications and Registration Procedures</a>”, BCP&nbsp;13, RFC&nbsp;4288, December&nbsp;2005.
1097            </td>
1098         </tr>
1099         <tr>
1100            <td class="reference"><b id="RFC5226">[RFC5226]</b></td>
1101            <td class="top"><a href="mailto:narten@us.ibm.com" title="IBM">Narten, T.</a> and <a href="mailto:Harald@Alvestrand.no" title="Google">H. Alvestrand</a>, “<a href="http://tools.ietf.org/html/rfc5226">Guidelines for Writing an IANA Considerations Section in RFCs</a>”, BCP&nbsp;26, RFC&nbsp;5226, May&nbsp;2008.
1102            </td>
1103         </tr>
1104      </table>
1105      <div class="avoidbreak">
1106         <h1 id="rfc.authors"><a href="#rfc.authors">Authors' Addresses</a></h1>
1107         <address class="vcard"><span class="vcardline"><span class="fn">Roy T. Fielding</span>
1108               (editor)
1109               <span class="n hidden"><span class="family-name">Fielding</span><span class="given-name">Roy T.</span></span></span><span class="org vcardline">Adobe Systems Incorporated</span><span class="adr"><span class="street-address vcardline">345 Park Ave</span><span class="vcardline"><span class="locality">San Jose</span>, <span class="region">CA</span>&nbsp;<span class="postal-code">95110</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:fielding@gbiv.com"><span class="email">fielding@gbiv.com</span></a></span><span class="vcardline">URI: <a href="http://roy.gbiv.com/" class="url">http://roy.gbiv.com/</a></span></address>
1110         <address class="vcard"><span class="vcardline"><span class="fn">Jim Gettys</span><span class="n hidden"><span class="family-name">Gettys</span><span class="given-name">Jim</span></span></span><span class="org vcardline">Alcatel-Lucent Bell Labs</span><span class="adr"><span class="street-address vcardline">21 Oak Knoll Road</span><span class="vcardline"><span class="locality">Carlisle</span>, <span class="region">MA</span>&nbsp;<span class="postal-code">01741</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:jg@freedesktop.org"><span class="email">jg@freedesktop.org</span></a></span><span class="vcardline">URI: <a href="http://gettys.wordpress.com/" class="url">http://gettys.wordpress.com/</a></span></address>
1111         <address class="vcard"><span class="vcardline"><span class="fn">Jeffrey C. Mogul</span><span class="n hidden"><span class="family-name">Mogul</span><span class="given-name">Jeffrey C.</span></span></span><span class="org vcardline">Hewlett-Packard Company</span><span class="adr"><span class="street-address vcardline">HP Labs, Large Scale Systems Group</span><span class="street-address vcardline">1501 Page Mill Road, MS 1177</span><span class="vcardline"><span class="locality">Palo Alto</span>, <span class="region">CA</span>&nbsp;<span class="postal-code">94304</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:JeffMogul@acm.org"><span class="email">JeffMogul@acm.org</span></a></span></address>
1112         <address class="vcard"><span class="vcardline"><span class="fn">Henrik Frystyk Nielsen</span><span class="n hidden"><span class="family-name">Frystyk</span></span></span><span class="org vcardline">Microsoft Corporation</span><span class="adr"><span class="street-address vcardline">1 Microsoft Way</span><span class="vcardline"><span class="locality">Redmond</span>, <span class="region">WA</span>&nbsp;<span class="postal-code">98052</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:henrikn@microsoft.com"><span class="email">henrikn@microsoft.com</span></a></span></address>
1113         <address class="vcard"><span class="vcardline"><span class="fn">Larry Masinter</span><span class="n hidden"><span class="family-name">Masinter</span><span class="given-name">Larry</span></span></span><span class="org vcardline">Adobe Systems Incorporated</span><span class="adr"><span class="street-address vcardline">345 Park Ave</span><span class="vcardline"><span class="locality">San Jose</span>, <span class="region">CA</span>&nbsp;<span class="postal-code">95110</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:LMM@acm.org"><span class="email">LMM@acm.org</span></a></span><span class="vcardline">URI: <a href="http://larry.masinter.net/" class="url">http://larry.masinter.net/</a></span></address>
1114         <address class="vcard"><span class="vcardline"><span class="fn">Paul J. Leach</span><span class="n hidden"><span class="family-name">Leach</span><span class="given-name">Paul J.</span></span></span><span class="org vcardline">Microsoft Corporation</span><span class="adr"><span class="street-address vcardline">1 Microsoft Way</span><span class="vcardline"><span class="locality">Redmond</span>, <span class="region">WA</span>&nbsp;<span class="postal-code">98052</span></span></span><span class="vcardline">Email: <a href="mailto:paulle@microsoft.com"><span class="email">paulle@microsoft.com</span></a></span></address>
1115         <address class="vcard"><span class="vcardline"><span class="fn">Tim Berners-Lee</span><span class="n hidden"><span class="family-name">Berners-Lee</span><span class="given-name">Tim</span></span></span><span class="org vcardline">World Wide Web Consortium</span><span class="adr"><span class="street-address vcardline">MIT Computer Science and Artificial Intelligence Laboratory</span><span class="street-address vcardline">The Stata Center, Building 32</span><span class="street-address vcardline">32 Vassar Street</span><span class="vcardline"><span class="locality">Cambridge</span>, <span class="region">MA</span>&nbsp;<span class="postal-code">02139</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:timbl@w3.org"><span class="email">timbl@w3.org</span></a></span><span class="vcardline">URI: <a href="http://www.w3.org/People/Berners-Lee/" class="url">http://www.w3.org/People/Berners-Lee/</a></span></address>
1116         <address class="vcard"><span class="vcardline"><span class="fn">Yves Lafon</span>
1117               (editor)
1118               <span class="n hidden"><span class="family-name">Lafon</span><span class="given-name">Yves</span></span></span><span class="org vcardline">World Wide Web Consortium</span><span class="adr"><span class="street-address vcardline">W3C / ERCIM</span><span class="street-address vcardline">2004, rte des Lucioles</span><span class="vcardline"><span class="locality">Sophia-Antipolis</span>, <span class="region">AM</span>&nbsp;<span class="postal-code">06902</span></span><span class="country-name vcardline">France</span></span><span class="vcardline">Email: <a href="mailto:ylafon@w3.org"><span class="email">ylafon@w3.org</span></a></span><span class="vcardline">URI: <a href="http://www.raubacapeu.net/people/yves/" class="url">http://www.raubacapeu.net/people/yves/</a></span></address>
1119         <address class="vcard"><span class="vcardline"><span class="fn">Julian F. Reschke</span>
1120               (editor)
1121               <span class="n hidden"><span class="family-name">Reschke</span><span class="given-name">Julian F.</span></span></span><span class="org vcardline">greenbytes GmbH</span><span class="adr"><span class="street-address vcardline">Hafenweg 16</span><span class="vcardline"><span class="locality">Muenster</span>, <span class="region">NW</span>&nbsp;<span class="postal-code">48155</span></span><span class="country-name vcardline">Germany</span></span><span class="vcardline tel">Phone: <a href="tel:+492512807760"><span class="value">+49 251 2807760</span></a></span><span class="vcardline tel"><span class="type">Fax</span>: <a href="fax:+492512807761"><span class="value">+49 251 2807761</span></a></span><span class="vcardline">Email: <a href="mailto:julian.reschke@greenbytes.de"><span class="email">julian.reschke@greenbytes.de</span></a></span><span class="vcardline">URI: <a href="http://greenbytes.de/tech/webdav/" class="url">http://greenbytes.de/tech/webdav/</a></span></address>
1122      </div>
1123      <div id="rfc.iref.m.1"></div>
1124      <div id="rfc.iref.m.2"></div>
1125      <h1 id="rfc.section.A" class="np"><a href="#rfc.section.A">A.</a>&nbsp;<a id="internet.media.type.multipart.byteranges" href="#internet.media.type.multipart.byteranges">Internet Media Type multipart/byteranges</a></h1>
1126      <p id="rfc.section.A.p.1">When an HTTP 206 (Partial Content) response message includes the content of multiple ranges (a response to a request for multiple
1127         non-overlapping ranges), these are transmitted as a multipart message-body (<a href="#RFC2046" id="rfc.xref.RFC2046.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, <a href="http://tools.ietf.org/html/rfc2046#section-5.1">Section 5.1</a>). The media type for this purpose is called "multipart/byteranges". The following is to be registered with IANA <a href="#RFC4288" id="rfc.xref.RFC4288.1"><cite title="Media Type Specifications and Registration Procedures">[RFC4288]</cite></a>.
1128      </p>
1129      <div class="note" id="rfc.section.A.p.2"> 
1130         <p> <b>Note:</b> Despite the name "multipart/byteranges" is not limited to the byte ranges only.
1131         </p> 
1132      </div>
1133      <p id="rfc.section.A.p.3">The multipart/byteranges media type includes one or more parts, each with its own Content-Type and Content-Range fields. The
1134         required boundary parameter specifies the boundary string used to separate each body-part.
1135      </p>
1136      <p id="rfc.section.A.p.4"> </p>
1137      <dl>
1138         <dt>Type name:</dt>
1139         <dd>multipart</dd>
1140         <dt>Subtype name:</dt>
1141         <dd>byteranges</dd>
1142         <dt>Required parameters:</dt>
1143         <dd>boundary</dd>
1144         <dt>Optional parameters:</dt>
1145         <dd>none</dd>
1146         <dt>Encoding considerations:</dt>
1147         <dd>only "7bit", "8bit", or "binary" are permitted</dd>
1148         <dt>Security considerations:</dt>
1149         <dd>none</dd>
1150         <dt>Interoperability considerations:</dt>
1151         <dd>none</dd>
1152         <dt>Published specification:</dt>
1153         <dd>This specification (see <a href="#internet.media.type.multipart.byteranges" title="Internet Media Type multipart/byteranges">Appendix&nbsp;A</a>).
1154         </dd>
1155         <dt>Applications that use this media type:</dt>
1156         <dt>Additional information:</dt>
1157         <dd> 
1158            <dl>
1159               <dt>Magic number(s):</dt>
1160               <dd>none</dd>
1161               <dt>File extension(s):</dt>
1162               <dd>none</dd>
1163               <dt>Macintosh file type code(s):</dt>
1164               <dd>none</dd>
1165            </dl> 
1166         </dd>
1167         <dt>Person and email address to contact for further information:</dt>
1168         <dd>See Authors Section.</dd>
1169         <dt>Intended usage:</dt>
1170         <dd>COMMON</dd>
1171         <dt>Restrictions on usage:</dt>
1172         <dd>none</dd>
1173         <dt>Author/Change controller:</dt>
1174         <dd>IESG</dd>
1175      </dl>
1176      <div id="rfc.figure.u.24"></div>
1177      <p>For example:</p><pre class="text">  HTTP/1.1 206 Partial Content
1178  Date: Wed, 15 Nov 1995 06:25:24 GMT
1179  Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT
1180  Content-type: multipart/byteranges; boundary=THIS_STRING_SEPARATES
1181 
1182  --THIS_STRING_SEPARATES
1183  Content-type: application/pdf
1184  Content-range: bytes 500-999/8000
1185 
1186  ...the first range...
1187  --THIS_STRING_SEPARATES
1188  Content-type: application/pdf
1189  Content-range: bytes 7000-7999/8000
1190 
1191  ...the second range
1192  --THIS_STRING_SEPARATES--
1193</pre><div id="rfc.figure.u.25"></div>
1194      <p>Other example:</p>  <pre class="text">  HTTP/1.1 206 Partial Content
1195  Date: Tue, 14 Nov 1995 06:25:24 GMT
1196  Last-Modified: Tue, 14 July 04:58:08 GMT
1197  Content-type: multipart/byteranges; boundary=THIS_STRING_SEPARATES
1198 
1199  --THIS_STRING_SEPARATES
1200  Content-type: video/example
1201  Content-range: exampleunit 1.2-4.3/25
1202 
1203  ...the first range...
1204  --THIS_STRING_SEPARATES
1205  Content-type: video/example
1206  Content-range: exampleunit 11.2-14.3/25
1207 
1208  ...the second range
1209  --THIS_STRING_SEPARATES--
1210</pre> <p id="rfc.section.A.p.7">Notes: </p>
1211      <ol>
1212         <li>Additional CRLFs <em class="bcp14">MAY</em> precede the first boundary string in the body.
1213         </li>
1214         <li>Although <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> permits the boundary string to be quoted, some existing implementations handle a quoted boundary string incorrectly.
1215         </li>
1216         <li>A number of browsers and servers were coded to an early draft of the byteranges specification to use a media type of multipart/x-byteranges<span id="rfc.iref.m.3"></span><span id="rfc.iref.m.4"></span>, which is almost, but not quite compatible with the version documented in HTTP/1.1.
1217         </li>
1218      </ol>
1219      <h1 id="rfc.section.B"><a href="#rfc.section.B">B.</a>&nbsp;<a id="compatibility" href="#compatibility">Compatibility with Previous Versions</a></h1>
1220      <h2 id="rfc.section.B.1"><a href="#rfc.section.B.1">B.1</a>&nbsp;<a id="changes.from.rfc.2616" href="#changes.from.rfc.2616">Changes from RFC 2616</a></h2>
1221      <p id="rfc.section.B.1.p.1">Clarify that it is not ok to use a weak cache validator in a 206 response. (<a href="#status.206" id="rfc.xref.status.206.2" title="206 Partial Content">Section&nbsp;3.1</a>)
1222      </p>
1223      <p id="rfc.section.B.1.p.2">Change ABNF productions for header fields to only define the field value. (<a href="#header.fields" title="Header Field Definitions">Section&nbsp;5</a>)
1224      </p>
1225      <p id="rfc.section.B.1.p.3">Clarify that multipart/byteranges can consist of a single part. (<a href="#internet.media.type.multipart.byteranges" title="Internet Media Type multipart/byteranges">Appendix&nbsp;A</a>)
1226      </p>
1227      <h1 id="rfc.section.C"><a href="#rfc.section.C">C.</a>&nbsp;<a id="collected.abnf" href="#collected.abnf">Collected ABNF</a></h1>
1228      <div id="rfc.figure.u.26"></div> <pre class="inline"><a href="#header.accept-ranges" class="smpl">Accept-Ranges</a> = acceptable-ranges
1229
1230<a href="#header.content-range" class="smpl">Content-Range</a> = content-range-spec
1231
1232<a href="#abnf.dependencies" class="smpl">HTTP-date</a> = &lt;HTTP-date, defined in [Part1], Section 6.1&gt;
1233
1234<a href="#header.if-range" class="smpl">If-Range</a> = entity-tag / HTTP-date
1235
1236<a href="#core.rules" class="smpl">OWS</a> = &lt;OWS, defined in [Part1], Section 1.2.2&gt;
1237
1238<a href="#range.retrieval.requests" class="smpl">Range</a> = byte-ranges-specifier / other-ranges-specifier
1239
1240<a href="#header.accept-ranges" class="smpl">acceptable-ranges</a> = ( *( "," OWS ) range-unit *( OWS "," [ OWS
1241 range-unit ] ) ) / "none"
1242
1243<a href="#header.content-range" class="smpl">byte-content-range-spec</a> = bytes-unit SP byte-range-resp-spec "/" (
1244 instance-length / "*" )
1245<a href="#header.content-range" class="smpl">byte-range-resp-spec</a> = ( first-byte-pos "-" last-byte-pos ) / "*"
1246<a href="#rule.ranges-specifier" class="smpl">byte-range-set</a> = ( *( "," OWS ) byte-range-spec ) / (
1247 suffix-byte-range-spec *( OWS "," [ ( OWS byte-range-spec ) /
1248 suffix-byte-range-spec ] ) )
1249<a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> = first-byte-pos "-" [ last-byte-pos ]
1250<a href="#rule.ranges-specifier" class="smpl">byte-ranges-specifier</a> = bytes-unit "=" byte-range-set
1251<a href="#range.units" class="smpl">bytes-unit</a> = "bytes"
1252
1253<a href="#header.content-range" class="smpl">content-range-spec</a> = byte-content-range-spec /
1254 other-content-range-spec
1255
1256<a href="#abnf.dependencies" class="smpl">entity-tag</a> = &lt;entity-tag, defined in [Part4], Section 2.2&gt;
1257
1258<a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> = 1*DIGIT
1259
1260<a href="#header.content-range" class="smpl">instance-length</a> = 1*DIGIT
1261
1262<a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> = 1*DIGIT
1263
1264<a href="#header.content-range" class="smpl">other-content-range-spec</a> = other-range-unit SP other-range-resp-spec
1265<a href="#header.content-range" class="smpl">other-range-resp-spec</a> = *CHAR
1266<a href="#range.retrieval.requests" class="smpl">other-range-set</a> = 1*CHAR
1267<a href="#range.units" class="smpl">other-range-unit</a> = token
1268<a href="#range.retrieval.requests" class="smpl">other-ranges-specifier</a> = other-range-unit "=" other-range-set
1269
1270<a href="#range.units" class="smpl">range-unit</a> = bytes-unit / other-range-unit
1271
1272<a href="#rule.ranges-specifier" class="smpl">suffix-byte-range-spec</a> = "-" suffix-length
1273<a href="#rule.ranges-specifier" class="smpl">suffix-length</a> = 1*DIGIT
1274
1275<a href="#core.rules" class="smpl">token</a> = &lt;token, defined in [Part1], Section 1.2.2&gt;
1276</pre> <div id="rfc.figure.u.27"></div>
1277      <p>ABNF diagnostics:</p><pre class="inline">; Accept-Ranges defined but not used
1278; Content-Range defined but not used
1279; If-Range defined but not used
1280; Range defined but not used
1281</pre><h1 id="rfc.section.D"><a href="#rfc.section.D">D.</a>&nbsp;<a id="change.log" href="#change.log">Change Log (to be removed by RFC Editor before publication)</a></h1>
1282      <h2 id="rfc.section.D.1"><a href="#rfc.section.D.1">D.1</a>&nbsp;Since RFC 2616
1283      </h2>
1284      <p id="rfc.section.D.1.p.1">Extracted relevant partitions from <a href="#RFC2616" id="rfc.xref.RFC2616.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>.
1285      </p>
1286      <h2 id="rfc.section.D.2"><a href="#rfc.section.D.2">D.2</a>&nbsp;Since draft-ietf-httpbis-p5-range-00
1287      </h2>
1288      <p id="rfc.section.D.2.p.1">Closed issues: </p>
1289      <ul>
1290         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/18">http://tools.ietf.org/wg/httpbis/trac/ticket/18</a>&gt;: "Cache validators in 206 responses" (&lt;<a href="http://purl.org/NET/http-errata#ifrange206">http://purl.org/NET/http-errata#ifrange206</a>&gt;)
1291         </li>
1292         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/35">http://tools.ietf.org/wg/httpbis/trac/ticket/35</a>&gt;: "Normative and Informative references"
1293         </li>
1294         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/86">http://tools.ietf.org/wg/httpbis/trac/ticket/86</a>&gt;: "Normative up-to-date references"
1295         </li>
1296      </ul>
1297      <h2 id="rfc.section.D.3"><a href="#rfc.section.D.3">D.3</a>&nbsp;Since draft-ietf-httpbis-p5-range-01
1298      </h2>
1299      <p id="rfc.section.D.3.p.1">Closed issues: </p>
1300      <ul>
1301         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/55">http://tools.ietf.org/wg/httpbis/trac/ticket/55</a>&gt;: "Updating to RFC4288"
1302         </li>
1303      </ul>
1304      <p id="rfc.section.D.3.p.2">Ongoing work on ABNF conversion (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>&gt;):
1305      </p>
1306      <ul>
1307         <li>Add explicit references to BNF syntax and rules imported from other parts of the specification.</li>
1308      </ul>
1309      <h2 id="rfc.section.D.4"><a href="#rfc.section.D.4">D.4</a>&nbsp;<a id="changes.since.02" href="#changes.since.02">Since draft-ietf-httpbis-p5-range-02</a></h2>
1310      <p id="rfc.section.D.4.p.1">Ongoing work on IANA Message Header Field Registration (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/40">http://tools.ietf.org/wg/httpbis/trac/ticket/40</a>&gt;):
1311      </p>
1312      <ul>
1313         <li>Reference RFC 3984, and update header field registrations for headers defined in this document.</li>
1314      </ul>
1315      <h2 id="rfc.section.D.5"><a href="#rfc.section.D.5">D.5</a>&nbsp;<a id="changes.since.03" href="#changes.since.03">Since draft-ietf-httpbis-p5-range-03</a></h2>
1316      <p id="rfc.section.D.5.p.1">None.</p>
1317      <h2 id="rfc.section.D.6"><a href="#rfc.section.D.6">D.6</a>&nbsp;<a id="changes.since.04" href="#changes.since.04">Since draft-ietf-httpbis-p5-range-04</a></h2>
1318      <p id="rfc.section.D.6.p.1">Closed issues: </p>
1319      <ul>
1320         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/133">http://tools.ietf.org/wg/httpbis/trac/ticket/133</a>&gt;: "multipart/byteranges minimum number of parts"
1321         </li>
1322      </ul>
1323      <p id="rfc.section.D.6.p.2">Ongoing work on ABNF conversion (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>&gt;):
1324      </p>
1325      <ul>
1326         <li>Use "/" instead of "|" for alternatives.</li>
1327         <li>Introduce new ABNF rules for "bad" whitespace ("BWS"), optional whitespace ("OWS") and required whitespace ("RWS").</li>
1328         <li>Rewrite ABNFs to spell out whitespace rules, factor out header field value format definitions.</li>
1329      </ul>
1330      <h2 id="rfc.section.D.7"><a href="#rfc.section.D.7">D.7</a>&nbsp;<a id="changes.since.05" href="#changes.since.05">Since draft-ietf-httpbis-p5-range-05</a></h2>
1331      <p id="rfc.section.D.7.p.1">Closed issues: </p>
1332      <ul>
1333         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/142">http://tools.ietf.org/wg/httpbis/trac/ticket/142</a>&gt;: "State base for *-byte-pos and suffix-length"
1334         </li>
1335      </ul>
1336      <p id="rfc.section.D.7.p.2">Ongoing work on Custom Ranges (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/85">http://tools.ietf.org/wg/httpbis/trac/ticket/85</a>&gt;):
1337      </p>
1338      <ul>
1339         <li>Remove bias in favor of byte ranges; allow custom ranges in ABNF.</li>
1340      </ul>
1341      <p id="rfc.section.D.7.p.3">Final work on ABNF conversion (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>&gt;):
1342      </p>
1343      <ul>
1344         <li>Add appendix containing collected and expanded ABNF, reorganize ABNF introduction.</li>
1345      </ul>
1346      <h2 id="rfc.section.D.8"><a href="#rfc.section.D.8">D.8</a>&nbsp;<a id="changes.since.06" href="#changes.since.06">Since draft-ietf-httpbis-p5-range-06</a></h2>
1347      <p id="rfc.section.D.8.p.1">Closed issues: </p>
1348      <ul>
1349         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/161">http://tools.ietf.org/wg/httpbis/trac/ticket/161</a>&gt;: "base for numeric protocol elements"
1350         </li>
1351      </ul>
1352      <h2 id="rfc.section.D.9"><a href="#rfc.section.D.9">D.9</a>&nbsp;<a id="changes.since.07" href="#changes.since.07">Since draft-ietf-httpbis-p5-range-07</a></h2>
1353      <p id="rfc.section.D.9.p.1">Closed issues: </p>
1354      <ul>
1355         <li>Fixed discrepancy in the If-Range definition about allowed validators.</li>
1356         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/150">http://tools.ietf.org/wg/httpbis/trac/ticket/150</a>&gt;: "multipart/byteranges for custom range units"
1357         </li>
1358         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/151">http://tools.ietf.org/wg/httpbis/trac/ticket/151</a>&gt;: "range unit missing from other-ranges-specifier in Range header"
1359         </li>
1360         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/198">http://tools.ietf.org/wg/httpbis/trac/ticket/198</a>&gt;: "move IANA registrations for optional status codes"
1361         </li>
1362      </ul>
1363      <h2 id="rfc.section.D.10"><a href="#rfc.section.D.10">D.10</a>&nbsp;<a id="changes.since.08" href="#changes.since.08">Since draft-ietf-httpbis-p5-range-08</a></h2>
1364      <p id="rfc.section.D.10.p.1">No significant changes.</p>
1365      <h2 id="rfc.section.D.11"><a href="#rfc.section.D.11">D.11</a>&nbsp;<a id="changes.since.09" href="#changes.since.09">Since draft-ietf-httpbis-p5-range-09</a></h2>
1366      <p id="rfc.section.D.11.p.1">No significant changes.</p>
1367      <h2 id="rfc.section.D.12"><a href="#rfc.section.D.12">D.12</a>&nbsp;<a id="changes.since.10" href="#changes.since.10">Since draft-ietf-httpbis-p5-range-10</a></h2>
1368      <p id="rfc.section.D.12.p.1">Closed issues: </p>
1369      <ul>
1370         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/69">http://tools.ietf.org/wg/httpbis/trac/ticket/69</a>&gt;: "Clarify 'Requested Variant'"
1371         </li>
1372         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/109">http://tools.ietf.org/wg/httpbis/trac/ticket/109</a>&gt;: "Clarify entity / representation / variant terminology"
1373         </li>
1374         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/220">http://tools.ietf.org/wg/httpbis/trac/ticket/220</a>&gt;: "consider removing the 'changes from 2068' sections"
1375         </li>
1376      </ul>
1377      <p id="rfc.section.D.12.p.2">Ongoing work on Custom Ranges (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/85">http://tools.ietf.org/wg/httpbis/trac/ticket/85</a>&gt;):
1378      </p>
1379      <ul>
1380         <li>Add IANA registry.</li>
1381      </ul>
1382      <h2 id="rfc.section.D.13"><a href="#rfc.section.D.13">D.13</a>&nbsp;<a id="changes.since.11" href="#changes.since.11">Since draft-ietf-httpbis-p5-range-11</a></h2>
1383      <p id="rfc.section.D.13.p.1">Closed issues: </p>
1384      <ul>
1385         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/217">http://tools.ietf.org/wg/httpbis/trac/ticket/217</a>&gt;: "Caches can't be required to serve ranges"
1386         </li>
1387      </ul>
1388      <h2 id="rfc.section.D.14"><a href="#rfc.section.D.14">D.14</a>&nbsp;<a id="changes.since.12" href="#changes.since.12">Since draft-ietf-httpbis-p5-range-12</a></h2>
1389      <p id="rfc.section.D.14.p.1">Closed issues: </p>
1390      <ul>
1391         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/224">http://tools.ietf.org/wg/httpbis/trac/ticket/224</a>&gt;: "Header Classification"
1392         </li>
1393      </ul>
1394      <h2 id="rfc.section.D.15"><a href="#rfc.section.D.15">D.15</a>&nbsp;<a id="changes.since.13" href="#changes.since.13">Since draft-ietf-httpbis-p5-range-13</a></h2>
1395      <p id="rfc.section.D.15.p.1">Closed issues: </p>
1396      <ul>
1397         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/276">http://tools.ietf.org/wg/httpbis/trac/ticket/276</a>&gt;: "untangle ABNFs for header fields"
1398         </li>
1399      </ul>
1400      <h2 id="rfc.section.D.16"><a href="#rfc.section.D.16">D.16</a>&nbsp;<a id="changes.since.14" href="#changes.since.14">Since draft-ietf-httpbis-p5-range-14</a></h2>
1401      <p id="rfc.section.D.16.p.1">None.</p>
1402      <h2 id="rfc.section.D.17"><a href="#rfc.section.D.17">D.17</a>&nbsp;<a id="changes.since.15" href="#changes.since.15">Since draft-ietf-httpbis-p5-range-15</a></h2>
1403      <p id="rfc.section.D.17.p.1">Closed issues: </p>
1404      <ul>
1405         <li> &lt;<a href="http://trac.tools.ietf.org/wg/httpbis/trac/ticket/175">http://trac.tools.ietf.org/wg/httpbis/trac/ticket/175</a>&gt;: "Security consideration: range flooding"
1406         </li>
1407      </ul>
1408      <h1 id="rfc.index"><a href="#rfc.index">Index</a></h1>
1409      <p class="noprint"><a href="#rfc.index.2">2</a> <a href="#rfc.index.4">4</a> <a href="#rfc.index.A">A</a> <a href="#rfc.index.C">C</a> <a href="#rfc.index.G">G</a> <a href="#rfc.index.H">H</a> <a href="#rfc.index.I">I</a> <a href="#rfc.index.M">M</a> <a href="#rfc.index.P">P</a> <a href="#rfc.index.R">R</a> <a href="#rfc.index.S">S</a> 
1410      </p>
1411      <div class="print2col">
1412         <ul class="ind">
1413            <li><a id="rfc.index.2" href="#rfc.index.2"><b>2</b></a><ul>
1414                  <li>206 Partial Content (status code)&nbsp;&nbsp;<a href="#rfc.iref.3"><b>3.1</b></a>, <a href="#rfc.xref.status.206.1">6.1</a>, <a href="#rfc.xref.status.206.2">B.1</a></li>
1415               </ul>
1416            </li>
1417            <li><a id="rfc.index.4" href="#rfc.index.4"><b>4</b></a><ul>
1418                  <li>416 Requested Range Not Satisfiable (status code)&nbsp;&nbsp;<a href="#rfc.iref.4"><b>3.2</b></a>, <a href="#rfc.xref.status.416.1">5.2</a>, <a href="#rfc.xref.status.416.2">6.1</a></li>
1419               </ul>
1420            </li>
1421            <li><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul>
1422                  <li>Accept-Ranges header field&nbsp;&nbsp;<a href="#rfc.iref.a.1"><b>5.1</b></a>, <a href="#rfc.xref.header.accept-ranges.1">6.2</a></li>
1423               </ul>
1424            </li>
1425            <li><a id="rfc.index.C" href="#rfc.index.C"><b>C</b></a><ul>
1426                  <li>Content-Range header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-range.1">2</a>, <a href="#rfc.xref.header.content-range.2">3.1</a>, <a href="#rfc.xref.header.content-range.3">3.2</a>, <a href="#rfc.iref.c.1"><b>5.2</b></a>, <a href="#rfc.xref.header.content-range.4">6.2</a></li>
1427               </ul>
1428            </li>
1429            <li><a id="rfc.index.G" href="#rfc.index.G"><b>G</b></a><ul>
1430                  <li><tt>Grammar</tt>&nbsp;&nbsp;
1431                     <ul>
1432                        <li><tt>Accept-Ranges</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.4"><b>5.1</b></a></li>
1433                        <li><tt>acceptable-ranges</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.5"><b>5.1</b></a></li>
1434                        <li><tt>byte-content-range-spec</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.8"><b>5.2</b></a></li>
1435                        <li><tt>byte-range-resp-spec</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.9"><b>5.2</b></a></li>
1436                        <li><tt>byte-range-set</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.14"><b>5.4.1</b></a></li>
1437                        <li><tt>byte-range-spec</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.15"><b>5.4.1</b></a></li>
1438                        <li><tt>byte-ranges-specifier</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.13"><b>5.4.1</b></a></li>
1439                        <li><tt>bytes-unit</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.2"><b>2</b></a></li>
1440                        <li><tt>Content-Range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.6"><b>5.2</b></a></li>
1441                        <li><tt>content-range-spec</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.7"><b>5.2</b></a></li>
1442                        <li><tt>first-byte-pos</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.16"><b>5.4.1</b></a></li>
1443                        <li><tt>If-Range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.11"><b>5.3</b></a></li>
1444                        <li><tt>instance-length</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.10"><b>5.2</b></a></li>
1445                        <li><tt>last-byte-pos</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.17"><b>5.4.1</b></a></li>
1446                        <li><tt>other-range-unit</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.3"><b>2</b></a></li>
1447                        <li><tt>Range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.20"><b>5.4.2</b></a></li>
1448                        <li><tt>range-unit</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.1"><b>2</b></a></li>
1449                        <li><tt>ranges-specifier</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.12"><b>5.4.1</b></a></li>
1450                        <li><tt>suffix-byte-range-spec</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.18"><b>5.4.1</b></a></li>
1451                        <li><tt>suffix-length</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.19"><b>5.4.1</b></a></li>
1452                     </ul>
1453                  </li>
1454               </ul>
1455            </li>
1456            <li><a id="rfc.index.H" href="#rfc.index.H"><b>H</b></a><ul>
1457                  <li>Header Fields&nbsp;&nbsp;
1458                     <ul>
1459                        <li>Accept-Ranges&nbsp;&nbsp;<a href="#rfc.iref.h.1"><b>5.1</b></a>, <a href="#rfc.xref.header.accept-ranges.1">6.2</a></li>
1460                        <li>Content-Range&nbsp;&nbsp;<a href="#rfc.xref.header.content-range.1">2</a>, <a href="#rfc.xref.header.content-range.2">3.1</a>, <a href="#rfc.xref.header.content-range.3">3.2</a>, <a href="#rfc.iref.h.2"><b>5.2</b></a>, <a href="#rfc.xref.header.content-range.4">6.2</a></li>
1461                        <li>If-Range&nbsp;&nbsp;<a href="#rfc.xref.header.if-range.1">3.1</a>, <a href="#rfc.xref.header.if-range.2">3.2</a>, <a href="#rfc.iref.h.3"><b>5.3</b></a>, <a href="#rfc.xref.header.if-range.3">5.4.2</a>, <a href="#rfc.xref.header.if-range.4">6.2</a></li>
1462                        <li>Range&nbsp;&nbsp;<a href="#rfc.xref.header.range.1">2</a>, <a href="#rfc.xref.header.range.2">2</a>, <a href="#rfc.xref.header.range.3">3.1</a>, <a href="#rfc.xref.header.range.4">3.2</a>, <a href="#rfc.iref.h.4"><b>5.4</b></a>, <a href="#rfc.xref.header.range.5">6.2</a></li>
1463                     </ul>
1464                  </li>
1465               </ul>
1466            </li>
1467            <li><a id="rfc.index.I" href="#rfc.index.I"><b>I</b></a><ul>
1468                  <li>If-Range header field&nbsp;&nbsp;<a href="#rfc.xref.header.if-range.1">3.1</a>, <a href="#rfc.xref.header.if-range.2">3.2</a>, <a href="#rfc.iref.i.1"><b>5.3</b></a>, <a href="#rfc.xref.header.if-range.3">5.4.2</a>, <a href="#rfc.xref.header.if-range.4">6.2</a></li>
1469               </ul>
1470            </li>
1471            <li><a id="rfc.index.M" href="#rfc.index.M"><b>M</b></a><ul>
1472                  <li>Media Type&nbsp;&nbsp;
1473                     <ul>
1474                        <li>multipart/byteranges&nbsp;&nbsp;<a href="#rfc.iref.m.1"><b>A</b></a></li>
1475                        <li>multipart/x-byteranges&nbsp;&nbsp;<a href="#rfc.iref.m.4">A</a></li>
1476                     </ul>
1477                  </li>
1478                  <li>multipart/byteranges Media Type&nbsp;&nbsp;<a href="#rfc.iref.m.2"><b>A</b></a></li>
1479                  <li>multipart/x-byteranges Media Type&nbsp;&nbsp;<a href="#rfc.iref.m.3">A</a></li>
1480               </ul>
1481            </li>
1482            <li><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul>
1483                  <li><em>Part1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.1">1.2</a>, <a href="#rfc.xref.Part1.2">1.2.1</a>, <a href="#rfc.xref.Part1.3">1.2.1</a>, <a href="#rfc.xref.Part1.4">1.2.1</a>, <a href="#rfc.xref.Part1.5">1.2.2</a>, <a href="#Part1"><b>9.1</b></a><ul>
1484                        <li><em>Section 1.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.1">1.2</a></li>
1485                        <li><em>Section 1.2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.2">1.2.1</a>, <a href="#rfc.xref.Part1.3">1.2.1</a>, <a href="#rfc.xref.Part1.4">1.2.1</a></li>
1486                        <li><em>Section 6.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.5">1.2.2</a></li>
1487                     </ul>
1488                  </li>
1489                  <li><em>Part4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.1">1.2.2</a>, <a href="#rfc.xref.Part4.2">4</a>, <a href="#rfc.xref.Part4.3">5.3</a>, <a href="#rfc.xref.Part4.4">5.3</a>, <a href="#Part4"><b>9.1</b></a><ul>
1490                        <li><em>Section 2.1.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.4">5.3</a></li>
1491                        <li><em>Section 2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.1">1.2.2</a></li>
1492                        <li><em>Section 2.2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.2">4</a>, <a href="#rfc.xref.Part4.3">5.3</a></li>
1493                     </ul>
1494                  </li>
1495               </ul>
1496            </li>
1497            <li><a id="rfc.index.R" href="#rfc.index.R"><b>R</b></a><ul>
1498                  <li>Range header field&nbsp;&nbsp;<a href="#rfc.xref.header.range.1">2</a>, <a href="#rfc.xref.header.range.2">2</a>, <a href="#rfc.xref.header.range.3">3.1</a>, <a href="#rfc.xref.header.range.4">3.2</a>, <a href="#rfc.iref.r.1"><b>5.4</b></a>, <a href="#rfc.xref.header.range.5">6.2</a></li>
1499                  <li><em>RFC2046</em>&nbsp;&nbsp;<a href="#RFC2046"><b>9.1</b></a>, <a href="#rfc.xref.RFC2046.1">A</a>, <a href="#rfc.xref.RFC2046.2">A</a><ul>
1500                        <li><em>Section 5.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2046.1">A</a></li>
1501                     </ul>
1502                  </li>
1503                  <li><em>RFC2119</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2119.1">1.1</a>, <a href="#RFC2119"><b>9.1</b></a></li>
1504                  <li><em>RFC2616</em>&nbsp;&nbsp;<a href="#RFC2616"><b>9.2</b></a>, <a href="#rfc.xref.RFC2616.1">D.1</a></li>
1505                  <li><em>RFC3864</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3864.1">6.2</a>, <a href="#RFC3864"><b>9.2</b></a></li>
1506                  <li><em>RFC4288</em>&nbsp;&nbsp;<a href="#RFC4288"><b>9.2</b></a>, <a href="#rfc.xref.RFC4288.1">A</a></li>
1507                  <li><em>RFC5226</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5226.1">2.1</a>, <a href="#RFC5226"><b>9.2</b></a><ul>
1508                        <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5226.1">2.1</a></li>
1509                     </ul>
1510                  </li>
1511                  <li><em>RFC5234</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5234.1">1.2</a>, <a href="#rfc.xref.RFC5234.2">1.2</a>, <a href="#RFC5234"><b>9.1</b></a><ul>
1512                        <li><em>Appendix B.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5234.2">1.2</a></li>
1513                     </ul>
1514                  </li>
1515               </ul>
1516            </li>
1517            <li><a id="rfc.index.S" href="#rfc.index.S"><b>S</b></a><ul>
1518                  <li>Status Codes&nbsp;&nbsp;
1519                     <ul>
1520                        <li>206 Partial Content&nbsp;&nbsp;<a href="#rfc.iref.s.1"><b>3.1</b></a>, <a href="#rfc.xref.status.206.1">6.1</a>, <a href="#rfc.xref.status.206.2">B.1</a></li>
1521                        <li>416 Requested Range Not Satisfiable&nbsp;&nbsp;<a href="#rfc.iref.s.2"><b>3.2</b></a>, <a href="#rfc.xref.status.416.1">5.2</a>, <a href="#rfc.xref.status.416.2">6.1</a></li>
1522                     </ul>
1523                  </li>
1524               </ul>
1525            </li>
1526         </ul>
1527      </div>
1528   </body>
1529</html>
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