draft-ietf-httpbis-p5-range-10.txt   draft-ietf-httpbis-p5-range-11.txt 
HTTPbis Working Group R. Fielding, Ed. HTTPbis Working Group R. Fielding, Ed.
Internet-Draft Day Software Internet-Draft Day Software
Obsoletes: 2616 (if approved) J. Gettys Obsoletes: 2616 (if approved) J. Gettys
Intended status: Standards Track Alcatel-Lucent Intended status: Standards Track Alcatel-Lucent
Expires: January 13, 2011 J. Mogul Expires: February 5, 2011 J. Mogul
HP HP
H. Frystyk H. Frystyk
Microsoft Microsoft
L. Masinter L. Masinter
Adobe Systems Adobe Systems
P. Leach P. Leach
Microsoft Microsoft
T. Berners-Lee T. Berners-Lee
W3C/MIT W3C/MIT
Y. Lafon, Ed. Y. Lafon, Ed.
W3C W3C
J. Reschke, Ed. J. Reschke, Ed.
greenbytes greenbytes
July 12, 2010 August 4, 2010
HTTP/1.1, part 5: Range Requests and Partial Responses HTTP/1.1, part 5: Range Requests and Partial Responses
draft-ietf-httpbis-p5-range-10 draft-ietf-httpbis-p5-range-11
Abstract Abstract
The Hypertext Transfer Protocol (HTTP) is an application-level The Hypertext Transfer Protocol (HTTP) is an application-level
protocol for distributed, collaborative, hypermedia information protocol for distributed, collaborative, hypermedia information
systems. HTTP has been in use by the World Wide Web global systems. HTTP has been in use by the World Wide Web global
information initiative since 1990. This document is Part 5 of the information initiative since 1990. This document is Part 5 of the
seven-part specification that defines the protocol referred to as seven-part specification that defines the protocol referred to as
"HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 5 defines "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 5 defines
range-specific requests and the rules for constructing and combining range-specific requests and the rules for constructing and combining
responses to those requests. responses to those requests.
Editorial Note (To be removed by RFC Editor) Editorial Note (To be removed by RFC Editor)
Discussion of this draft should take place on the HTTPBIS working Discussion of this draft should take place on the HTTPBIS working
group mailing list (ietf-http-wg@w3.org). The current issues list is group mailing list (ietf-http-wg@w3.org). The current issues list is
at <http://tools.ietf.org/wg/httpbis/trac/report/3> and related at <http://tools.ietf.org/wg/httpbis/trac/report/3> and related
documents (including fancy diffs) can be found at documents (including fancy diffs) can be found at
<http://tools.ietf.org/wg/httpbis/>. <http://tools.ietf.org/wg/httpbis/>.
The changes in this draft are summarized in Appendix D.11. The changes in this draft are summarized in Appendix D.12.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 13, 2011. This Internet-Draft will expire on February 5, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 3, line 7 skipping to change at page 3, line 7
modifications of such material outside the IETF Standards Process. modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other it for publication as an RFC or to translate it into languages other
than English. than English.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 5
1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 4 1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 5
1.2.1. Core Rules . . . . . . . . . . . . . . . . . . . . . . 5 1.2.1. Core Rules . . . . . . . . . . . . . . . . . . . . . . 6
1.2.2. ABNF Rules defined in other Parts of the 1.2.2. ABNF Rules defined in other Parts of the
Specification . . . . . . . . . . . . . . . . . . . . 5 Specification . . . . . . . . . . . . . . . . . . . . 6
2. Range Units . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Range Units . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 5 2.1. Range Specifier Registry . . . . . . . . . . . . . . . . . 6
3.1. 206 Partial Content . . . . . . . . . . . . . . . . . . . 6 3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 7
3.2. 416 Requested Range Not Satisfiable . . . . . . . . . . . 6 3.1. 206 Partial Content . . . . . . . . . . . . . . . . . . . 7
4. Combining Ranges . . . . . . . . . . . . . . . . . . . . . . . 7 3.2. 416 Requested Range Not Satisfiable . . . . . . . . . . . 8
5. Header Field Definitions . . . . . . . . . . . . . . . . . . . 7 4. Combining Ranges . . . . . . . . . . . . . . . . . . . . . . . 8
5.1. Accept-Ranges . . . . . . . . . . . . . . . . . . . . . . 7 5. Header Field Definitions . . . . . . . . . . . . . . . . . . . 8
5.2. Content-Range . . . . . . . . . . . . . . . . . . . . . . 8 5.1. Accept-Ranges . . . . . . . . . . . . . . . . . . . . . . 9
5.3. If-Range . . . . . . . . . . . . . . . . . . . . . . . . . 10 5.2. Content-Range . . . . . . . . . . . . . . . . . . . . . . 9
5.4. Range . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5.3. If-Range . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.4.1. Byte Ranges . . . . . . . . . . . . . . . . . . . . . 11 5.4. Range . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.4.2. Range Retrieval Requests . . . . . . . . . . . . . . . 13 5.4.1. Byte Ranges . . . . . . . . . . . . . . . . . . . . . 12
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 5.4.2. Range Retrieval Requests . . . . . . . . . . . . . . . 14
6.1. Status Code Registration . . . . . . . . . . . . . . . . . 14 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
6.2. Message Header Registration . . . . . . . . . . . . . . . 14 6.1. Status Code Registration . . . . . . . . . . . . . . . . . 15
7. Security Considerations . . . . . . . . . . . . . . . . . . . 14 6.2. Header Field Registration . . . . . . . . . . . . . . . . 15
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 6.3. Range Specifier Registration . . . . . . . . . . . . . . . 16
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 7. Security Considerations . . . . . . . . . . . . . . . . . . . 16
9.1. Normative References . . . . . . . . . . . . . . . . . . . 15 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
9.2. Informative References . . . . . . . . . . . . . . . . . . 15 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Appendix A. Internet Media Type multipart/byteranges . . . . . . 16 9.1. Normative References . . . . . . . . . . . . . . . . . . . 16
Appendix B. Compatibility with Previous Versions . . . . . . . . 18 9.2. Informative References . . . . . . . . . . . . . . . . . . 17
B.1. Changes from RFC 2068 . . . . . . . . . . . . . . . . . . 18 Appendix A. Internet Media Type multipart/byteranges . . . . . . 17
B.2. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 18 Appendix B. Compatibility with Previous Versions . . . . . . . . 20
Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 19 B.1. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 20
Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 20
Appendix D. Change Log (to be removed by RFC Editor before Appendix D. Change Log (to be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . 20 publication) . . . . . . . . . . . . . . . . . . . . 21
D.1. Since RFC2616 . . . . . . . . . . . . . . . . . . . . . . 20 D.1. Since RFC2616 . . . . . . . . . . . . . . . . . . . . . . 21
D.2. Since draft-ietf-httpbis-p5-range-00 . . . . . . . . . . . 20 D.2. Since draft-ietf-httpbis-p5-range-00 . . . . . . . . . . . 21
D.3. Since draft-ietf-httpbis-p5-range-01 . . . . . . . . . . . 20 D.3. Since draft-ietf-httpbis-p5-range-01 . . . . . . . . . . . 22
D.4. Since draft-ietf-httpbis-p5-range-02 . . . . . . . . . . . 21 D.4. Since draft-ietf-httpbis-p5-range-02 . . . . . . . . . . . 22
D.5. Since draft-ietf-httpbis-p5-range-03 . . . . . . . . . . . 21 D.5. Since draft-ietf-httpbis-p5-range-03 . . . . . . . . . . . 22
D.6. Since draft-ietf-httpbis-p5-range-04 . . . . . . . . . . . 21 D.6. Since draft-ietf-httpbis-p5-range-04 . . . . . . . . . . . 22
D.7. Since draft-ietf-httpbis-p5-range-05 . . . . . . . . . . . 21 D.7. Since draft-ietf-httpbis-p5-range-05 . . . . . . . . . . . 22
D.8. Since draft-ietf-httpbis-p5-range-06 . . . . . . . . . . . 22 D.8. Since draft-ietf-httpbis-p5-range-06 . . . . . . . . . . . 23
D.9. Since draft-ietf-httpbis-p5-range-07 . . . . . . . . . . . 22 D.9. Since draft-ietf-httpbis-p5-range-07 . . . . . . . . . . . 23
D.10. Since draft-ietf-httpbis-p5-range-08 . . . . . . . . . . . 22 D.10. Since draft-ietf-httpbis-p5-range-08 . . . . . . . . . . . 23
D.11. Since draft-ietf-httpbis-p5-range-09 . . . . . . . . . . . 22 D.11. Since draft-ietf-httpbis-p5-range-09 . . . . . . . . . . . 23
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 D.12. Since draft-ietf-httpbis-p5-range-10 . . . . . . . . . . . 23
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1. Introduction 1. Introduction
HTTP clients often encounter interrupted data transfers as a result HTTP clients often encounter interrupted data transfers as a result
of cancelled requests or dropped connections. When a cache has of cancelled requests or dropped connections. When a cache has
stored a partial representation, it is desirable to request the stored a partial representation, it is desirable to request the
remainder of that representation in a subsequent request rather than remainder of that representation in a subsequent request rather than
transfer the entire representation. There are also a number of Web transfer the entire representation. There are also a number of Web
applications that benefit from being able to request only a subset of applications that benefit from being able to request only a subset of
a larger representation, such as a single page of a very large a larger representation, such as a single page of a very large
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The ABNF rules below are defined in other parts: The ABNF rules below are defined in other parts:
HTTP-date = <HTTP-date, defined in [Part1], Section 6.1> HTTP-date = <HTTP-date, defined in [Part1], Section 6.1>
entity-tag = <entity-tag, defined in [Part4], Section 2> entity-tag = <entity-tag, defined in [Part4], Section 2>
2. Range Units 2. Range Units
HTTP/1.1 allows a client to request that only part (a range of) the HTTP/1.1 allows a client to request that only part (a range of) the
response entity be included within the response. HTTP/1.1 uses range representation be included within the response. HTTP/1.1 uses range
units in the Range (Section 5.4) and Content-Range (Section 5.2) units in the Range (Section 5.4) and Content-Range (Section 5.2)
header fields. An entity can be broken down into subranges according header fields. A representation can be broken down into subranges
to various structural units. according to various structural units.
range-unit = bytes-unit / other-range-unit range-unit = bytes-unit / other-range-unit
bytes-unit = "bytes" bytes-unit = "bytes"
other-range-unit = token other-range-unit = token
HTTP/1.1 has been designed to allow implementations of applications HTTP/1.1 has been designed to allow implementations of applications
that do not depend on knowledge of ranges. The only range unit that do not depend on knowledge of ranges. The only range unit
defined by HTTP/1.1 is "bytes". defined by HTTP/1.1 is "bytes". Additional specifiers can be defined
as described in Section 2.1.
If a range unit is not understood in a request, a server MUST ignore If a range unit is not understood in a request, a server MUST ignore
the whole Range header (Section 5.4). If a range unit is not the whole Range header (Section 5.4). If a range unit is not
understood in a response, an intermediary SHOULD pass the response to understood in a response, an intermediary SHOULD pass the response to
the client; a client MUST fail. the client; a client MUST fail.
2.1. Range Specifier Registry
The HTTP Ranger Specifier Registry defines the name space for the
range specifier names.
Registrations MUST include the following fields:
o Name
o Description
o Pointer to specification text
Values to be added to this name space are subject to IETF review
([RFC5226], Section 4.1).
The registry itself is maintained at
<http://www.iana.org/assignments/http-range-specifiers>.
3. Status Code Definitions 3. Status Code Definitions
3.1. 206 Partial Content 3.1. 206 Partial Content
The server has fulfilled the partial GET request for the resource. The server has fulfilled the partial GET request for the resource.
The request MUST have included a Range header field (Section 5.4) The request MUST have included a Range header field (Section 5.4)
indicating the desired range, and MAY have included an If-Range indicating the desired range, and MAY have included an If-Range
header field (Section 5.3) to make the request conditional. header field (Section 5.3) to make the request conditional.
The response MUST include the following header fields: The response MUST include the following header fields:
o Either a Content-Range header field (Section 5.2) indicating the o Either a Content-Range header field (Section 5.2) indicating the
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The request MUST have included a Range header field (Section 5.4) The request MUST have included a Range header field (Section 5.4)
indicating the desired range, and MAY have included an If-Range indicating the desired range, and MAY have included an If-Range
header field (Section 5.3) to make the request conditional. header field (Section 5.3) to make the request conditional.
The response MUST include the following header fields: The response MUST include the following header fields:
o Either a Content-Range header field (Section 5.2) indicating the o Either a Content-Range header field (Section 5.2) indicating the
range included with this response, or a multipart/byteranges range included with this response, or a multipart/byteranges
Content-Type including Content-Range fields for each part. If a Content-Type including Content-Range fields for each part. If a
Content-Length header field is present in the response, its value Content-Length header field is present in the response, its value
MUST match the actual number of OCTETs transmitted in the message- MUST match the actual number of octets transmitted in the message-
body. body.
o Date o Date
o ETag and/or Content-Location, if the header would have been sent o Cache-Control, ETag, Expires, Content-Location, Last-Modified,
in a 200 response to the same request and/or Vary, if the header field would have been sent in a 200
response to the same request
o Expires, Cache-Control, and/or Vary, if the field-value might
differ from that sent in any previous response for the same
variant
If the 206 response is the result of an If-Range request, the If the 206 response is the result of an If-Range request, the
response SHOULD NOT include other entity-headers. Otherwise, the response SHOULD NOT include other representation header fields.
response MUST include all of the entity-headers that would have been Otherwise, the response MUST include all of the representation header
returned with a 200 (OK) response to the same request. fields that would have been returned with a 200 (OK) response to the
same request.
A cache MUST NOT combine a 206 response with other previously cached A cache MUST NOT combine a 206 response with other previously cached
content if the ETag or Last-Modified headers do not match exactly, content if the ETag or Last-Modified headers do not match exactly,
see Section 4. see Section 4.
A cache that does not support the Range and Content-Range headers A cache that does not support the Range and Content-Range headers
MUST NOT cache 206 (Partial Content) responses. Furthermore, if a MUST NOT cache 206 (Partial Content) responses. Furthermore, if a
response uses a range unit that is not understood by the cache, then response uses a range unit that is not understood by the cache, then
it MUST NOT be cached either. it MUST NOT be cached either.
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3.2. 416 Requested Range Not Satisfiable 3.2. 416 Requested Range Not Satisfiable
A server SHOULD return a response with this status code if a request A server SHOULD return a response with this status code if a request
included a Range request-header field (Section 5.4), and none of the included a Range request-header field (Section 5.4), and none of the
ranges-specifier values in this field overlap the current extent of ranges-specifier values in this field overlap the current extent of
the selected resource, and the request did not include an If-Range the selected resource, and the request did not include an If-Range
request-header field (Section 5.3). (For byte-ranges, this means request-header field (Section 5.3). (For byte-ranges, this means
that the first-byte-pos of all of the byte-range-spec values were that the first-byte-pos of all of the byte-range-spec values were
greater than the current length of the selected resource.) greater than the current length of the selected resource.)
When this status code is returned for a byte-range request, the When this status code is returned for a byte-range request, the
response SHOULD include a Content-Range entity-header field response SHOULD include a Content-Range header field specifying the
specifying the current length of the selected resource (see current length of the representation (see Section 5.2). This
Section 5.2). This response MUST NOT use the multipart/byteranges response MUST NOT use the multipart/byteranges content-type.
content-type.
4. Combining Ranges 4. Combining Ranges
A response might transfer only a subrange of an entity-body, either A response might transfer only a subrange of a representation, either
because the request included one or more Range specifications, or because the request included one or more Range specifications, or
because a connection was broken prematurely. After several such because a connection closed prematurely. After several such
transfers, a cache might have received several ranges of the same transfers, a cache might have received several ranges of the same
entity-body. representation.
If a cache has a stored non-empty set of subranges for an entity, and If a cache has a stored non-empty set of subranges for a
an incoming response transfers another subrange, the cache MAY representation, and an incoming response transfers another subrange,
combine the new subrange with the existing set if both the following the cache MAY combine the new subrange with the existing set if both
conditions are met: the following conditions are met:
o Both the incoming response and the cache entry have a cache o Both the incoming response and the cache entry have a cache
validator. validator.
o The two cache validators match using the strong comparison o The two cache validators match using the strong comparison
function (see Section 4 of [Part4]). function (see Section 4 of [Part4]).
If either requirement is not met, the cache MUST use only the most If either requirement is not met, the cache MUST use only the most
recent partial response (based on the Date values transmitted with recent partial response (based on the Date values transmitted with
every response, and using the incoming response if these values are every response, and using the incoming response if these values are
equal or missing), and MUST discard the other partial information. equal or missing), and MUST discard the other partial information.
5. Header Field Definitions 5. Header Field Definitions
This section defines the syntax and semantics of HTTP/1.1 header This section defines the syntax and semantics of HTTP/1.1 header
fields related to range requests and partial responses. fields related to range requests and partial responses.
For entity-header fields, both sender and recipient refer to either
the client or the server, depending on who sends and who receives the
entity.
5.1. Accept-Ranges 5.1. Accept-Ranges
The "Accept-Ranges" response-header field allows a resource to The "Accept-Ranges" response-header field allows a resource to
indicate its acceptance of range requests. indicate its acceptance of range requests.
Accept-Ranges = "Accept-Ranges" ":" OWS Accept-Ranges-v Accept-Ranges = "Accept-Ranges" ":" OWS Accept-Ranges-v
Accept-Ranges-v = acceptable-ranges Accept-Ranges-v = acceptable-ranges
acceptable-ranges = 1#range-unit / "none" acceptable-ranges = 1#range-unit / "none"
Origin servers that accept byte-range requests MAY send Origin servers that accept byte-range requests MAY send
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Servers that do not accept any kind of range request for a resource Servers that do not accept any kind of range request for a resource
MAY send MAY send
Accept-Ranges: none Accept-Ranges: none
to advise the client not to attempt a range request. to advise the client not to attempt a range request.
5.2. Content-Range 5.2. Content-Range
The "Content-Range" entity-header field is sent with a partial The "Content-Range" header field is sent with a partial
entity-body to specify where in the full entity-body the partial body representation to specify where in the full representation the
should be applied. Range units are defined in Section 2. payload body is intended to be applied.
Range units are defined in Section 2.
Content-Range = "Content-Range" ":" OWS Content-Range-v Content-Range = "Content-Range" ":" OWS Content-Range-v
Content-Range-v = content-range-spec Content-Range-v = content-range-spec
content-range-spec = byte-content-range-spec content-range-spec = byte-content-range-spec
/ other-content-range-spec / other-content-range-spec
byte-content-range-spec = bytes-unit SP byte-content-range-spec = bytes-unit SP
byte-range-resp-spec "/" byte-range-resp-spec "/"
( instance-length / "*" ) ( instance-length / "*" )
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byte-range-resp-spec "/" byte-range-resp-spec "/"
( instance-length / "*" ) ( instance-length / "*" )
byte-range-resp-spec = (first-byte-pos "-" last-byte-pos) byte-range-resp-spec = (first-byte-pos "-" last-byte-pos)
/ "*" / "*"
instance-length = 1*DIGIT instance-length = 1*DIGIT
other-content-range-spec = other-range-unit SP other-content-range-spec = other-range-unit SP
other-range-resp-spec other-range-resp-spec
other-range-resp-spec = *CHAR other-range-resp-spec = *CHAR
The header SHOULD indicate the total length of the full entity-body, The header SHOULD indicate the total length of the full
unless this length is unknown or difficult to determine. The representation, unless this length is unknown or difficult to
asterisk "*" character means that the instance-length is unknown at determine. The asterisk "*" character means that the instance-length
the time when the response was generated. is unknown at the time when the response was generated.
Unlike byte-ranges-specifier values (see Section 5.4.1), a byte- Unlike byte-ranges-specifier values (see Section 5.4.1), a byte-
range-resp-spec MUST only specify one range, and MUST contain range-resp-spec MUST only specify one range, and MUST contain
absolute byte positions for both the first and last byte of the absolute byte positions for both the first and last byte of the
range. range.
A byte-content-range-spec with a byte-range-resp-spec whose last- 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 whose byte-pos value is less than its first-byte-pos value, or whose
instance-length value is less than or equal to its last-byte-pos instance-length value is less than or equal to its last-byte-pos
value, is invalid. The recipient of an invalid byte-content-range- value, is invalid. The recipient of an invalid byte-content-range-
spec MUST ignore it and any content transferred along with it. spec MUST ignore it and any content transferred along with it.
In the case of a byte range request: A server sending a response with In the case of a byte range request: A server sending a response with
status code 416 (Requested range not satisfiable) SHOULD include a status code 416 (Requested range not satisfiable) SHOULD include a
Content-Range field with a byte-range-resp-spec of "*". The Content-Range field with a byte-range-resp-spec of "*". The
instance-length specifies the current length of the selected instance-length specifies the current length of the selected
resource. A response with status code 206 (Partial Content) MUST NOT resource. A response with status code 206 (Partial Content) MUST NOT
include a Content-Range field with a byte-range-resp-spec of "*". include a Content-Range field with a byte-range-resp-spec of "*".
Examples of byte-content-range-spec values, assuming that the entity Examples of byte-content-range-spec values, assuming that the
contains a total of 1234 bytes: representation contains a total of 1234 bytes:
o The first 500 bytes: o The first 500 bytes:
bytes 0-499/1234 bytes 0-499/1234
o The second 500 bytes: o The second 500 bytes:
bytes 500-999/1234 bytes 500-999/1234
o All except for the first 500 bytes: o All except for the first 500 bytes:
skipping to change at page 10, line 5 skipping to change at page 11, line 17
Date: Wed, 15 Nov 1995 06:25:24 GMT Date: Wed, 15 Nov 1995 06:25:24 GMT
Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT
Content-Range: bytes 21010-47021/47022 Content-Range: bytes 21010-47021/47022
Content-Length: 26012 Content-Length: 26012
Content-Type: image/gif Content-Type: image/gif
When an HTTP message includes the content of multiple ranges (for When an HTTP message includes the content of multiple ranges (for
example, a response to a request for multiple non-overlapping example, a response to a request for multiple non-overlapping
ranges), these are transmitted as a multipart message. The multipart ranges), these are transmitted as a multipart message. The multipart
media type used for this purpose is "multipart/byteranges" as defined media type used for this purpose is "multipart/byteranges" as defined
in Appendix A. See Appendix B.1 for a compatibility issue. in Appendix A.
A response to a request for a single range MUST NOT be sent using the A response to a request for a single range MUST NOT be sent using the
multipart/byteranges media type. A response to a request for multipart/byteranges media type. A response to a request for
multiple ranges, whose result is a single range, MAY be sent as a multiple ranges, whose result is a single range, MAY be sent as a
multipart/byteranges media type with one part. A client that cannot multipart/byteranges media type with one part. A client that cannot
decode a multipart/byteranges message MUST NOT ask for multiple decode a multipart/byteranges message MUST NOT ask for multiple
ranges in a single request. ranges in a single request.
When a client requests multiple ranges in one request, the server When a client requests multiple ranges in one request, the server
SHOULD return them in the order that they appeared in the request. SHOULD return them in the order that they appeared in the request.
If the server ignores a byte-range-spec because it is syntactically If the server ignores a byte-range-spec because it is syntactically
invalid, the server SHOULD treat the request as if the invalid Range invalid, the server SHOULD treat the request as if the invalid Range
header field did not exist. (Normally, this means return a 200 header field did not exist. (Normally, this means return a 200
response containing the full entity). response containing the full representation).
If the server receives a request (other than one including an If- If the server receives a request (other than one including an If-
Range request-header field) with an unsatisfiable Range request- Range request-header field) with an unsatisfiable Range request-
header field (that is, all of whose byte-range-spec values have a header field (that is, all of whose byte-range-spec values have a
first-byte-pos value greater than the current length of the selected first-byte-pos value greater than the current length of the selected
resource), it SHOULD return a response code of 416 (Requested range resource), it SHOULD return a response code of 416 (Requested range
not satisfiable) (Section 3.2). not satisfiable) (Section 3.2).
Note: Clients cannot depend on servers to send a 416 (Requested Note: Clients cannot depend on servers to send a 416 (Requested
range not satisfiable) response instead of a 200 (OK) response for range not satisfiable) response instead of a 200 (OK) response for
an unsatisfiable Range request-header, since not all servers an unsatisfiable Range request-header, since not all servers
implement this request-header. implement this request-header.
5.3. If-Range 5.3. If-Range
If a client has a partial copy of an entity in its cache, and wishes If a client has a partial copy of a representation in its cache, and
to have an up-to-date copy of the entire entity in its cache, it wishes to have an up-to-date copy of the entire representation in its
could use the Range request-header with a conditional GET (using cache, it could use the Range request-header with a conditional GET
either or both of If-Unmodified-Since and If-Match.) However, if the (using either or both of If-Unmodified-Since and If-Match.) However,
condition fails because the entity has been modified, the client if the condition fails because the representation has been modified,
would then have to make a second request to obtain the entire current the client would then have to make a second request to obtain the
entity-body. entire current representation.
The "If-Range" request-header field allows a client to "short- The "If-Range" request-header field allows a client to "short-
circuit" the second request. Informally, its meaning is "if the circuit" the second request. Informally, its meaning is "if the
entity is unchanged, send me the part(s) that I am missing; representation is unchanged, send me the part(s) that I am missing;
otherwise, send me the entire new entity". otherwise, send me the entire new representation".
If-Range = "If-Range" ":" OWS If-Range-v If-Range = "If-Range" ":" OWS If-Range-v
If-Range-v = entity-tag / HTTP-date If-Range-v = entity-tag / HTTP-date
If the client has no entity tag for an entity, but does have a Last- If the client has no entity-tag for a representation, but does have a
Modified date, it MAY use that date in an If-Range header. (The Last-Modified date, it MAY use that date in an If-Range header. (The
server can distinguish between a valid HTTP-date and any form of server can distinguish between a valid HTTP-date and any form of
entity-tag by examining no more than two characters.) The If-Range entity-tag by examining no more than two characters.) The If-Range
header SHOULD only be used together with a Range header, and MUST be header SHOULD only be used together with a Range header, and MUST be
ignored if the request does not include a Range header, or if the ignored if the request does not include a Range header, or if the
server does not support the sub-range operation. server does not support the sub-range operation.
If the entity tag given in the If-Range header matches the current If the entity-tag given in the If-Range header matches the current
cache validator for the entity, then the server SHOULD provide the cache validator for the representation, then the server SHOULD
specified sub-range of the entity using a 206 (Partial Content) provide the specified sub-range of the representation using a 206
response. If the cache validator does not match, then the server (Partial Content) response. If the cache validator does not match,
SHOULD return the entire entity using a 200 (OK) response. then the server SHOULD return the entire representation using a 200
(OK) response.
5.4. Range 5.4. Range
5.4.1. Byte Ranges 5.4.1. Byte Ranges
Since all HTTP entities are represented in HTTP messages as sequences Since all HTTP representations are transferred as sequences of bytes,
of bytes, the concept of a byte range is meaningful for any HTTP the concept of a byte range is meaningful for any HTTP
entity. (However, not all clients and servers need to support byte- representation. (However, not all clients and servers need to
range operations.) support byte-range operations.)
Byte range specifications in HTTP apply to the sequence of bytes in Byte range specifications in HTTP apply to the sequence of bytes in
the entity-body (not necessarily the same as the message-body). the representation body (not necessarily the same as the message-
body).
A byte range operation MAY specify a single range of bytes, or a set A byte range operation MAY specify a single range of bytes, or a set
of ranges within a single entity. of ranges within a single representation.
byte-ranges-specifier = bytes-unit "=" byte-range-set byte-ranges-specifier = bytes-unit "=" byte-range-set
byte-range-set = 1#( byte-range-spec / suffix-byte-range-spec ) byte-range-set = 1#( byte-range-spec / suffix-byte-range-spec )
byte-range-spec = first-byte-pos "-" [ last-byte-pos ] byte-range-spec = first-byte-pos "-" [ last-byte-pos ]
first-byte-pos = 1*DIGIT first-byte-pos = 1*DIGIT
last-byte-pos = 1*DIGIT last-byte-pos = 1*DIGIT
The first-byte-pos value in a byte-range-spec gives the byte-offset 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 gives the of the first byte in a range. The last-byte-pos value gives the
byte-offset of the last byte in the range; that is, the byte byte-offset of the last byte in the range; that is, the byte
positions specified are inclusive. Byte offsets start at zero. positions specified are inclusive. Byte offsets start at zero.
If the last-byte-pos value is present, it MUST be greater than or If the last-byte-pos value is present, it MUST be greater than or
equal to the first-byte-pos in that byte-range-spec, or the byte- equal to the first-byte-pos in that byte-range-spec, or the byte-
range-spec is syntactically invalid. The recipient of a byte-range- range-spec is syntactically invalid. The recipient of a byte-range-
set that includes one or more syntactically invalid byte-range-spec set that includes one or more syntactically invalid byte-range-spec
values MUST ignore the header field that includes that byte-range- values MUST ignore the header field that includes that byte-range-
set. set.
If the last-byte-pos value is absent, or if the value is greater than If the last-byte-pos value is absent, or if the value is greater than
or equal to the current length of the entity-body, last-byte-pos is or equal to the current length of the representation body, last-byte-
taken to be equal to one less than the current length of the entity- pos is taken to be equal to one less than the current length of the
body in bytes. representation in bytes.
By its choice of last-byte-pos, a client can limit the number of By its choice of last-byte-pos, a client can limit the number of
bytes retrieved without knowing the size of the entity. bytes retrieved without knowing the size of the representation.
suffix-byte-range-spec = "-" suffix-length suffix-byte-range-spec = "-" suffix-length
suffix-length = 1*DIGIT suffix-length = 1*DIGIT
A suffix-byte-range-spec is used to specify the suffix of the entity- A suffix-byte-range-spec is used to specify the suffix of the
body, of a length given by the suffix-length value. (That is, this representation body, of a length given by the suffix-length value.
form specifies the last N bytes of an entity-body.) If the entity is (That is, this form specifies the last N bytes of a representation.)
shorter than the specified suffix-length, the entire entity-body is If the representation is shorter than the specified suffix-length,
used. the entire representation is used.
If a syntactically valid byte-range-set includes at least one byte- If a syntactically valid byte-range-set includes at least one byte-
range-spec whose first-byte-pos is less than the current length of range-spec whose first-byte-pos is less than the current length of
the entity-body, or at least one suffix-byte-range-spec with a non- the representation, or at least one suffix-byte-range-spec with a
zero suffix-length, then the byte-range-set is satisfiable. non-zero suffix-length, then the byte-range-set is satisfiable.
Otherwise, the byte-range-set is unsatisfiable. If the byte-range- Otherwise, the byte-range-set is unsatisfiable. If the byte-range-
set is unsatisfiable, the server SHOULD return a response with a set is unsatisfiable, the server SHOULD return a response with a 416
status of 416 (Requested range not satisfiable). Otherwise, the (Requested range not satisfiable) status code. Otherwise, the server
server SHOULD return a response with a status of 206 (Partial SHOULD return a response with a 206 (Partial Content) status code
Content) containing the satisfiable ranges of the entity-body. containing the satisfiable ranges of the representation.
Examples of byte-ranges-specifier values (assuming an entity-body of Examples of byte-ranges-specifier values (assuming a representation
length 10000): of length 10000):
o The first 500 bytes (byte offsets 0-499, inclusive): o The first 500 bytes (byte offsets 0-499, inclusive):
bytes=0-499 bytes=0-499
o The second 500 bytes (byte offsets 500-999, inclusive): o The second 500 bytes (byte offsets 500-999, inclusive):
bytes=500-999 bytes=500-999
o The final 500 bytes (byte offsets 9500-9999, inclusive): o The final 500 bytes (byte offsets 9500-9999, inclusive):
skipping to change at page 13, line 14 skipping to change at page 14, line 30
o Several legal but not canonical specifications of the second 500 o Several legal but not canonical specifications of the second 500
bytes (byte offsets 500-999, inclusive): bytes (byte offsets 500-999, inclusive):
bytes=500-600,601-999 bytes=500-600,601-999
bytes=500-700,601-999 bytes=500-700,601-999
5.4.2. Range Retrieval Requests 5.4.2. Range Retrieval Requests
The "Range" request-header field defines the GET method (conditional The "Range" request-header field defines the GET method (conditional
or not) to request one or more sub-ranges of the response entity- or not) to request one or more sub-ranges of the response
body, instead of the entire entity body. representation body, instead of the entire representation body.
Range = "Range" ":" OWS Range-v Range = "Range" ":" OWS Range-v
Range-v = byte-ranges-specifier Range-v = byte-ranges-specifier
/ other-ranges-specifier / other-ranges-specifier
other-ranges-specifier = other-range-unit "=" other-range-set other-ranges-specifier = other-range-unit "=" other-range-set
other-range-set = 1*CHAR other-range-set = 1*CHAR
A server MAY ignore the Range header. However, HTTP/1.1 origin A server MAY ignore the Range header. However, HTTP/1.1 origin
servers and intermediate caches ought to support byte ranges when servers and intermediate caches ought to support byte ranges when
possible, since Range supports efficient recovery from partially possible, since Range supports efficient recovery from partially
failed transfers, and supports efficient partial retrieval of large failed transfers, and supports efficient partial retrieval of large
entities. representations.
If the server supports the Range header and the specified range or If the server supports the Range header and the specified range or
ranges are appropriate for the entity: ranges are appropriate for the representation:
o The presence of a Range header in an unconditional GET modifies o The presence of a Range header in an unconditional GET modifies
what is returned if the GET is otherwise successful. In other what is returned if the GET is otherwise successful. In other
words, the response carries a status code of 206 (Partial Content) words, the response carries a status code of 206 (Partial Content)
instead of 200 (OK). instead of 200 (OK).
o The presence of a Range header in a conditional GET (a request o The presence of a Range header in a conditional GET (a request
using one or both of If-Modified-Since and If-None-Match, or one using one or both of If-Modified-Since and If-None-Match, or one
or both of If-Unmodified-Since and If-Match) modifies what is or both of If-Unmodified-Since and If-Match) modifies what is
returned if the GET is otherwise successful and the condition is returned if the GET is otherwise successful and the condition is
true. It does not affect the 304 (Not Modified) response returned true. It does not affect the 304 (Not Modified) response returned
if the conditional is false. if the conditional is false.
In some cases, it might be more appropriate to use the If-Range In some cases, it might be more appropriate to use the If-Range
header (see Section 5.3) in addition to the Range header. header (see Section 5.3) in addition to the Range header.
If a proxy that supports ranges receives a Range request, forwards If a proxy that supports ranges receives a Range request, forwards
the request to an inbound server, and receives an entire entity in the request to an inbound server, and receives an entire
reply, it SHOULD only return the requested range to its client. It representation in reply, it SHOULD only return the requested range to
SHOULD store the entire received response in its cache if that is its client. It SHOULD store the entire received response in its
consistent with its cache allocation policies. cache if that is consistent with its cache allocation policies.
6. IANA Considerations 6. IANA Considerations
6.1. Status Code Registration 6.1. Status Code Registration
The HTTP Status Code Registry located at The HTTP Status Code Registry located at
<http://www.iana.org/assignments/http-status-codes> should be updated <http://www.iana.org/assignments/http-status-codes> shall be updated
with the registrations below: with the registrations below:
+-------+---------------------------------+-------------+ +-------+---------------------------------+-------------+
| Value | Description | Reference | | Value | Description | Reference |
+-------+---------------------------------+-------------+ +-------+---------------------------------+-------------+
| 206 | Partial Content | Section 3.1 | | 206 | Partial Content | Section 3.1 |
| 416 | Requested Range Not Satisfiable | Section 3.2 | | 416 | Requested Range Not Satisfiable | Section 3.2 |
+-------+---------------------------------+-------------+ +-------+---------------------------------+-------------+
6.2. Message Header Registration 6.2. Header Field Registration
The Message Header Registry located at <http://www.iana.org/ The Message Header Field Registry located at <http://www.iana.org/
assignments/message-headers/message-header-index.html> should be assignments/message-headers/message-header-index.html> shall be
updated with the permanent registrations below (see [RFC3864]): updated with the permanent registrations below (see [RFC3864]):
+-------------------+----------+----------+-------------+ +-------------------+----------+----------+-------------+
| Header Field Name | Protocol | Status | Reference | | Header Field Name | Protocol | Status | Reference |
+-------------------+----------+----------+-------------+ +-------------------+----------+----------+-------------+
| Accept-Ranges | http | standard | Section 5.1 | | Accept-Ranges | http | standard | Section 5.1 |
| Content-Range | http | standard | Section 5.2 | | Content-Range | http | standard | Section 5.2 |
| If-Range | http | standard | Section 5.3 | | If-Range | http | standard | Section 5.3 |
| Range | http | standard | Section 5.4 | | Range | http | standard | Section 5.4 |
+-------------------+----------+----------+-------------+ +-------------------+----------+----------+-------------+
The change controller is: "IETF (iesg@ietf.org) - Internet The change controller is: "IETF (iesg@ietf.org) - Internet
Engineering Task Force". Engineering Task Force".
6.3. Range Specifier Registration
The registration procedure for HTTP Range Specifiers is defined by
Section 2.1 of this document.
The HTTP Range Specifier Registry shall be created at
<http://www.iana.org/assignments/http-range-specifiers> and be
populated with the registrations below:
+----------------------+-------------------+----------------------+
| Range Specifier Name | Description | Reference |
+----------------------+-------------------+----------------------+
| bytes | a range of octets | (this specification) |
+----------------------+-------------------+----------------------+
The change controller is: "IETF (iesg@ietf.org) - Internet
Engineering Task Force".
7. Security Considerations 7. Security Considerations
No additional security considerations have been identified beyond No additional security considerations have been identified beyond
those applicable to HTTP in general [Part1]. those applicable to HTTP in general [Part1].
8. Acknowledgments 8. Acknowledgments
Most of the specification of ranges is based on work originally done Most of the specification of ranges is based on work originally done
by Ari Luotonen and John Franks, with additional input from Steve by Ari Luotonen and John Franks, with additional input from Steve
Zilles, Daniel W. Connolly, Roy T. Fielding, Jim Gettys, Martin Zilles, Daniel W. Connolly, Roy T. Fielding, Jim Gettys, Martin
skipping to change at page 15, line 4 skipping to change at page 16, line 38
8. Acknowledgments 8. Acknowledgments
Most of the specification of ranges is based on work originally done Most of the specification of ranges is based on work originally done
by Ari Luotonen and John Franks, with additional input from Steve by Ari Luotonen and John Franks, with additional input from Steve
Zilles, Daniel W. Connolly, Roy T. Fielding, Jim Gettys, Martin Zilles, Daniel W. Connolly, Roy T. Fielding, Jim Gettys, Martin
Hamilton, Koen Holtman, Shel Kaplan, Paul Leach, Alex Lopez-Ortiz, Hamilton, Koen Holtman, Shel Kaplan, Paul Leach, Alex Lopez-Ortiz,
Larry Masinter, Jeff Mogul, Lou Montulli, David W. Morris, Luigi Larry Masinter, Jeff Mogul, Lou Montulli, David W. Morris, Luigi
Rizzo, and Bill Weihl. Rizzo, and Bill Weihl.
9. References 9. References
9.1. Normative References 9.1. Normative References
[Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., [Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed.,
and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections, and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections,
and Message Parsing", draft-ietf-httpbis-p1-messaging-10 and Message Parsing", draft-ietf-httpbis-p1-messaging-11
(work in progress), July 2010. (work in progress), August 2010.
[Part3] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed.,
and J. Reschke, Ed., "HTTP/1.1, part 3: Message Payload
and Content Negotiation", draft-ietf-httpbis-p3-payload-10
(work in progress), July 2010.
[Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., [Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed.,
and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional
Requests", draft-ietf-httpbis-p4-conditional-10 (work in Requests", draft-ietf-httpbis-p4-conditional-11 (work in
progress), July 2010. progress), August 2010.
[Part6] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed.,
Nottingham, M., Ed., and J. Reschke, Ed., "HTTP/1.1, part
6: Caching", draft-ietf-httpbis-p6-cache-10 (work in
progress), July 2010.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046, Extensions (MIME) Part Two: Media Types", RFC 2046,
November 1996. November 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008. Specifications: ABNF", STD 68, RFC 5234, January 2008.
skipping to change at page 16, line 5 skipping to change at page 17, line 28
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration
Procedures for Message Header Fields", BCP 90, RFC 3864, Procedures for Message Header Fields", BCP 90, RFC 3864,
September 2004. September 2004.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", BCP 13, RFC 4288, December 2005. Registration Procedures", BCP 13, RFC 4288, December 2005.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
Appendix A. Internet Media Type multipart/byteranges Appendix A. Internet Media Type multipart/byteranges
When an HTTP 206 (Partial Content) response message includes the When an HTTP 206 (Partial Content) response message includes the
content of multiple ranges (a response to a request for multiple non- content of multiple ranges (a response to a request for multiple non-
overlapping ranges), these are transmitted as a multipart message- overlapping ranges), these are transmitted as a multipart message-
body ([RFC2046], Section 5.1). The media type for this purpose is body ([RFC2046], Section 5.1). The media type for this purpose is
called "multipart/byteranges". The following is to be registered called "multipart/byteranges". The following is to be registered
with IANA [RFC4288]. with IANA [RFC4288].
Note: Despite the name "multipart/byteranges" is not limited to Note: Despite the name "multipart/byteranges" is not limited to
skipping to change at page 18, line 5 skipping to change at page 19, line 44
...the first range... ...the first range...
--THIS_STRING_SEPARATES --THIS_STRING_SEPARATES
Content-type: video/example Content-type: video/example
Content-range: exampleunit 11.2-14.3/25 Content-range: exampleunit 11.2-14.3/25
...the second range ...the second range
--THIS_STRING_SEPARATES-- --THIS_STRING_SEPARATES--
Notes: Notes:
1. Additional CRLFs may precede the first boundary string in the 1. Additional CRLFs MAY precede the first boundary string in the
entity. body.
2. Although [RFC2046] permits the boundary string to be quoted, some 2. Although [RFC2046] permits the boundary string to be quoted, some
existing implementations handle a quoted boundary string existing implementations handle a quoted boundary string
incorrectly. incorrectly.
3. A number of browsers and servers were coded to an early draft of 3. A number of browsers and servers were coded to an early draft of
the byteranges specification to use a media type of multipart/ the byteranges specification to use a media type of multipart/
x-byteranges, which is almost, but not quite compatible with the x-byteranges, which is almost, but not quite compatible with the
version documented in HTTP/1.1. version documented in HTTP/1.1.
Appendix B. Compatibility with Previous Versions Appendix B. Compatibility with Previous Versions
B.1. Changes from RFC 2068 B.1. Changes from RFC 2616
Transfer-coding and message lengths all interact in ways that
required fixing exactly when chunked encoding is used (to allow for
transfer encoding that may not be self delimiting); it was important
to straighten out exactly how message lengths are computed.
(Section 5.2, see also [Part1], [Part3] and [Part6])
There are situations where a server (especially a proxy) does not
know the full length of a response but is capable of serving a
byterange request. We therefore need a mechanism to allow byteranges
with a content-range not indicating the full length of the message.
(Section 5.2)
Range request responses would become very verbose if all meta-data
were always returned; by allowing the server to only send needed
headers in a 206 response, this problem can be avoided. (Section 3.1
and 5.3)
Fix problem with unsatisfiable range requests; there are two cases:
syntactic problems, and range doesn't exist in the document. The 416
status code was needed to resolve this ambiguity needed to indicate
an error for a byte range request that falls outside of the actual
contents of a document. (Section 3.2, 5.2)
B.2. Changes from RFC 2616
Clarify that it is not ok to use a weak cache validator in a 206 Clarify that it is not ok to use a weak cache validator in a 206
response. (Section 3.1) response. (Section 3.1)
Clarify that multipart/byteranges can consist of a single part. Clarify that multipart/byteranges can consist of a single part.
(Appendix A) (Appendix A)
Appendix C. Collected ABNF Appendix C. Collected ABNF
Accept-Ranges = "Accept-Ranges:" OWS Accept-Ranges-v Accept-Ranges = "Accept-Ranges:" OWS Accept-Ranges-v
Accept-Ranges-v = acceptable-ranges Accept-Ranges-v = acceptable-ranges
Content-Range = "Content-Range:" OWS Content-Range-v Content-Range = "Content-Range:" OWS Content-Range-v
Content-Range-v = content-range-spec Content-Range-v = content-range-spec
HTTP-date = <HTTP-date, defined in [Part1], Section 6.1> HTTP-date = <HTTP-date, defined in [Part1], Section 6.1>
If-Range = "If-Range:" OWS If-Range-v If-Range = "If-Range:" OWS If-Range-v
If-Range-v = entity-tag / HTTP-date If-Range-v = entity-tag / HTTP-date
skipping to change at page 22, line 36 skipping to change at page 23, line 47
registrations for optional status codes" registrations for optional status codes"
D.10. Since draft-ietf-httpbis-p5-range-08 D.10. Since draft-ietf-httpbis-p5-range-08
No significant changes. No significant changes.
D.11. Since draft-ietf-httpbis-p5-range-09 D.11. Since draft-ietf-httpbis-p5-range-09
No significant changes. No significant changes.
D.12. Since draft-ietf-httpbis-p5-range-10
Closed issues:
o <http://tools.ietf.org/wg/httpbis/trac/ticket/69>: "Clarify
'Requested Variant'"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/109>: "Clarify
entity / representation / variant terminology"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/220>: "consider
removing the 'changes from 2068' sections"
Ongoing work on Custom Ranges
(<http://tools.ietf.org/wg/httpbis/trac/ticket/85>):
o Add IANA registry.
Index Index
2 2
206 Partial Content (status code) 6 206 Partial Content (status code) 7
4 4
416 Requested Range Not Satisfiable (status code) 6 416 Requested Range Not Satisfiable (status code) 8
A A
Accept-Ranges header 7 Accept-Ranges header 9
C C
Content-Range header 8 Content-Range header 9
G G
Grammar Grammar
Accept-Ranges 7 Accept-Ranges 9
Accept-Ranges-v 7 Accept-Ranges-v 9
acceptable-ranges 7 acceptable-ranges 9
byte-content-range-spec 8 byte-content-range-spec 9
byte-range-resp-spec 8 byte-range-resp-spec 9
byte-range-set 11 byte-range-set 12
byte-range-spec 11 byte-range-spec 12
byte-ranges-specifier 11 byte-ranges-specifier 12
bytes-unit 5 bytes-unit 6
Content-Range 8 Content-Range 9
content-range-spec 8 content-range-spec 9
Content-Range-v 8 Content-Range-v 9
first-byte-pos 11 first-byte-pos 12
If-Range 10 If-Range 12
If-Range-v 10 If-Range-v 12
instance-length 8 instance-length 9
last-byte-pos 11 last-byte-pos 12
other-range-unit 5 other-range-unit 6
Range 13 Range 14
range-unit 5 range-unit 6
ranges-specifier 11 ranges-specifier 12
suffix-byte-range-spec 12 suffix-byte-range-spec 13
suffix-length 12 suffix-length 13
H H
Headers Headers
Accept-Ranges 7 Accept-Ranges 9
Content-Range 8 Content-Range 9
If-Range 10 If-Range 11
Range 11 Range 12
I I
If-Range header 10 If-Range header 11
M M
Media Type Media Type
multipart/byteranges 16 multipart/byteranges 17
multipart/x-byteranges 18 multipart/x-byteranges 20
multipart/byteranges Media Type 16 multipart/byteranges Media Type 17
multipart/x-byteranges Media Type 18 multipart/x-byteranges Media Type 20
R R
Range header 11 Range header 12
S S
Status Codes Status Codes
206 Partial Content 6 206 Partial Content 7
416 Requested Range Not Satisfiable 6 416 Requested Range Not Satisfiable 8
Authors' Addresses Authors' Addresses
Roy T. Fielding (editor) Roy T. Fielding (editor)
Day Software Day Software
23 Corporate Plaza DR, Suite 280 23 Corporate Plaza DR, Suite 280
Newport Beach, CA 92660 Newport Beach, CA 92660
USA USA
Phone: +1-949-706-5300 Phone: +1-949-706-5300
 End of changes. 68 change blocks. 
222 lines changed or deleted 250 lines changed or added

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