1992

中央网信办学习贯彻十九大精神湖北首场宣讲报告会举行

Status of this memo

This document is an Internet Draft. Internet Drafts are working documents of the Internet Engineering Task Force (IETF), its Areas, and its Working Groups. Note that other groups may also distribute working documents as Internet Drafts.

Internet Drafts are working documents valid for a maximum of six months. Internet Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet Drafts as reference material or to cite them other than as a "working draft" or "work in progress".

This document is a DRAFT specification of a protocol in use on the internet and to be proposed as an Internet standard. Discussion of this protocol takes place on the www-talk@info.cern.ch mailing list -- to subscribe mail to www-talk-request@info.cern.ch. Distribution of this memo is unlimited.

Abstract

HTTP is a protocol with the lightness and speed necessary for a distributed collaborative hypermedia information system. It is a generic stateless object-oriented protocol, which may be used for many similar tasks such as name servers, and distributed object-oriented systems, by extending the commands, or "methods", used. A feature if HTTP is the negotiation of data representation, allowing systems to be built independently of the development of new advanced representations.

Note: This specification

This HTTP protocol is an upgrade on the original protocol as implemented in the earliest WWW releases. It is back-compatible with that more limited protocol.

This specification includes the following parts:

• The Request
• Methods
• A list of headers in the request message
• The response
• Status codes
• Metainformation headers on any object transmitted
• The content of any object content transmitted
• Format negotiation algorithm
• The HTTP Registration Authority
• Security Considerations
• Unresolved points
• References

The following notes form recommended practice not part of the specification:

Servers tolerating clients

Clients tolerating servers

Purpose

When many sources of networked information are available to a reader, and when a discipline of reference between different sources exists, it is possible to rapidly follow references between units of information which are provided at different remote locations. As response times should ideally be of the order of 100ms in, for example, a hypertext jump, this requires a fast, stateless, information retrieval protocol.

Practical information systems require more functionality than simple retrieval, including search, front-end update and annotation. This protocol allows an open-ended set of methods to be used. It builds on the discipline of reference provided by the Universal Resource Identifier (URI) as a name (URN, RFCxxxx) or address (URL, RFCxxxx) allows the object of the method to be specified.

Reference is made to the Multipurpose Internet Mail Extensions (MIME, RFC1341) which are used to allow objects to be transmitted in an open variety of representations.

Overall operation

On the internet, the communication takes place over a TCP/IP connection. This does not preclude this protocol being implemented over any other protocol on the internet or other networks. In these cases, the mapping of the HTTP request and response structures onto the transport data units of the protocol in question is outside the scope of this specification. It should not however be at all complicated.

The protocol is basically stateless, a transaction consisting of

Connection

The establishment of a connection by the client to the server - when using TCP/IP port 80 is the well-known port, but other non-reserverd ports may be specified in the URL;

Request

The sending, by the client, of a request message to the server;

Response

The sending, by the server, of a response to the client;

Close

The closing of the connection by either both parties.

The format of the request and response parts is defined in this specification. Whilst header information defined in this specification is sent in ISO Latin-1 character set in CRLF terminated lines, object transmission in binary is possible.

Character sets

In all cases in HTTP where RFC822 characters are allowed, these may be extended to use the full ISO Latin 1 character set. 8-bit transmission is always used.