Changeset 158 for draft-ietf-httpbis/latest/p5-range.xml

Timestamp:

Jan 10, 2008, 9:57:39 PM (12 years ago)

Author:

fielding@…

Message:

editorial: add introduction for ranges

File:

• draft-ietf-httpbis/latest/p5-range.xml (modified) (1 diff)

draft-ietf-httpbis/latest/p5-range.xml

@@ -204 +204 @@
 <section title="Introduction" anchor="introduction">
 <t>
-   This document will define aspects of HTTP related to range requests,
-   partial responses, and the multipart/byteranges media type.  Right now
-   it only includes the extracted relevant sections of
-   <xref target="RFC2616">RFC 2616</xref> without edit.
+   HTTP clients often encounter interrupted data transfers as a result
+   of cancelled requests or dropped connections.  When a cache has stored
+   a partial representation, it is desirable to request the remainder
+   of that representation in a subsequent request rather than transfer
+   the entire representation.
+   There are also a number of Web applications that benefit from being
+   able to request only a subset of a larger representation, such as a
+   single page of a very large document or only part of an image to be
+   rendered by a device with limited local storage.
+</t>
+<t>
+   This document defines aspects of HTTP/1.1 related to range requests,
+   partial responses, and the multipart/byteranges media type.
+   The protocol for range requests is an &OPTIONAL; feature of HTTP/1.1,
+   designed so resources or recipients that do not implement this feature
+   can respond as if it is a normal GET request without impacting
+   interoperability.  Partial responses are indicated by a distinct status
+   code to not be mistaken for full responses by intermediate caches
+   that might not implement the feature.
+</t>
+<t>
+   Although the HTTP/1.1 range request mechanism is designed to allow for
+   extensible range types, this specification only defines requests for
+   byte ranges.
 </t>