CICS Web support upgrade to HTTP/1.1

CICS® Web support now supports HTTP/1.1.

Releases of CICS before CICS Transaction Server for z/OS®, Version 3 Release 1 supported HTTP/1.0. CICS Web support is now enhanced to handle and provide features of the HTTP/1.1 specification, including chunked transfer-coding, pipelining, and persistent connections.

CICS Web support is conditionally compliant with the HTTP/1.1 specification, as described in the Internet Society and IETF (Internet Engineering Task Force) Request for Comments document RFC 2616, Hypertext Transfer Protocol - HTTP/1.1. (RFC 2616 is available to download from http://www.ietf.org/rfc/rfc2616.txt.) Conditional compliance with the HTTP/1.1 specification means that CICS satisfies all the "MUST" level requirements, but not all the "SHOULD" level requirements, that are detailed in the HTTP/1.1 specification, where these requirements are relevant to the functions actually provided by CICS itself. Your user application programs share the responsibility for compliance in the actions that they perform, and guidance is provided to help you make your application programs compliant, when you are ready to do that.

New behavior for CICS TS Version 3

Changed behavior, compared to CICS TS Version 2

HTTP functions not supported by CICS Web support

The HTTP/1.1 specification (RFC 2616) defines various roles for the parties that make use of the HTTP protocol. CICS Web support provides HTTP services that are appropriate for an origin server, for a client, and for a user agent (although a human user might not be involved for every HTTP client request).

The HTTP/1.1 specification also includes requirements that relate to roles which are not relevant to CICS Web support, and these can be ignored:
  • CICS does not act as a proxy.
  • CICS does not act as a gateway (an intermediary for another server) or a tunnel (a relay between HTTP connections).
  • CICS does not provide caching facilities, or provide support for user-written caching facilities.
  • CICS is not designed for use as a Web browser.