This Working Group is charged with maintaining and developing the "core" specifications for HTTP. The Working Group's specification deliverables are: * A document (or set of documents) that is suitable to supersede RFC 2616 as the definition of HTTP/1.1 and move RFC 2817 to Historic status * A document cataloguing the security properties of HTTP/1.1 * A document (or set of documents) that specifies HTTP/2.0, an improved binding of HTTP's semantics to an underlying transport. HTTP/1.1 -------- HTTP/1.1 is one of the most successful and widely-used protocols on the Internet today. However, its specification has several editorial issues. Additionally, after years of implementation and extension, several ambiguities have become evident, impairing interoperability and the ability to easily implement and use HTTP. The working group will refine RFC2616 to: * Incorporate errata and updates (e.g., references, IANA registries, ABNF) * Fix editorial problems which have led to misunderstandings of the specification * Clarify conformance requirements * Remove known ambiguities where they affect interoperability * Clarify existing methods of extensibility * Remove or deprecate those features that are not widely implemented and also unduly affect interoperability * Where necessary, add implementation advice * Document the security properties of HTTP and its associated mechanisms (e.g., Basic and Digest authentication, cookies, TLS) for common applications It will also incorporate the generic authentication framework from RFC 2617, without obsoleting or updating that specification's definition of the Basic and Digest schemes. Finally, it will incorporate relevant portions of RFC 2817 (in particular, the CONNECT method and advice on the use of Upgrade), so that that specification can be moved to Historic status. In doing so, it should consider: * Implementer experience * Demonstrated use of HTTP * Impact on existing implementations and deployments HTTP/2.0 -------- There is emerging implementation experience and interest in a protocol that retains the semantics of HTTP without the legacy of HTTP/1.x message framing and syntax, which have been identified as hampering performance and encouraging misuse of the underlying transport. The Working Group will produce a specification of a new expression of HTTP's current semantics in ordered, bi-directional streams. As with HTTP/1.x, the primary target transport is TCP, but it should be possible to use other transports. Work will begin using draft-mbelshe-httpbis-spdy-00 as a starting point; proposals are to be expressed in terms of changes to that document. Note that consensus is required both for changes to the document and anything that remains in the document. In particular, because something is in the initial document does not imply that there is consensus around the feature or how it is specified. The deliverable of the WG is HTTP/2.0, and there is no consideration of preserving backwards compatibility with the initial starting point. As part of the HTTP/2.0 work, the following issues are explicitly called out for consideration: * A negotiation mechanism that is capable of not only choosing between HTTP/1.x and HTTP/2.x, but also for bindings of HTTP URLs to other transports (for example). * Header compression (which may encompass header encoding or tokenisation) * Server push (which may encompass pull or other techniques) It is expected that HTTP/2.0 will: * Substantially and measurably improve end-user perceived latency in most cases, over HTTP/1.1 using TCP. * Address the "head of line blocking" problem in HTTP. * Not require multiple connections to a server to enable parallelism, thus improving its use of TCP, especially regarding congestion control. * Retain the semantics of HTTP/1.1, leveraging existing documentation (see above), including (but not limited to) HTTP methods, status codes, URIs, and where appropriate, header fields. * Clearly define how HTTP/2.0 interacts with HTTP/1.x, especially in intermediaries (both 2->1 and 1->2). * Clearly identify any new extensibility points and policy for their appropriate use. The resulting specification(s) are expected to meet these goals for common existing deployments of HTTP; in particular, Web browsing (desktop and mobile), non-browsers ("HTTP APIs"), Web serving (at a variety of scales), and intermediation (by proxies, corporate firewalls, "reverse" proxies and Content Delivery Networks). Likewise, current and future semantic extensions to HTTP/1.x (e.g., headers, methods, status codes, cache directives) should be supported in the new protocol. Note that this does not include uses of HTTP where non-specified behaviours are relied upon (e.g., connection state such as timeouts or client affinity, and "interception" proxies); these uses may or may not be enabled by the final product. Explicitly out-of-scope items include: * Specifying the use of alternate transport-layer protocols. Note that it is expected that the Working Group will work with the TLS working group to define how the protocol is used with the TLS Protocol; any revisions to RFC 2818 will be done in the TLS working group. * Specifying how the HTTP protocol is to be used or presented in a specific use case (e.g., in Web browsers). The Working Group will coordinate this item with: * The TLS Working Group, regarding use of TLS. * The Transport Area, regarding impact on and interaction with transport protocols. * The HYBI Working Group, regarding the possible future extension of HTTP/2.0 to carry WebSockets semantics. The Working Group will give priority to HTTP/1.1 work until that work is complete. Other HTTP-Related Work ----------------------- The Working Group may define additional extensions to HTTP as work items, provided that: * The Working Group Chairs judge that there is consensus to take on the item and believe that it will not interfere with the work described above, and * The Area Directors approve the addition and add corresponding milestones. Additionally, the Working Group will not start work on any extensions that are specific to HTTP/2.0 until the HTTP/2.0 work is completed.