CICS web support and non-HTTP requests

You can use CICS® web support to process inbound TCP/IP client requests that are not in the HTTP format, primarily to support requests from user-written clients that use nonstandard request formats. You define the processing and the response. No specific support is provided for any formally defined protocols for client-server communication.

CICS web support handles non-HTTP messages only when CICS is the server. CICS client requests made through CICS web support use the HTTP protocol.

Note these points about CICS web support when handling non-HTTP requests:
  • You can use TCPIPSERVICE resource definitions to control the ports on which requests are received.
  • You can use an analyzer program to assemble and parse requests, specify code page conversion, and determine subsequent request processing. You can code the analyzer program to parse requests in accordance with any request format that you have defined, but note that CICS does not provide specific support for any particular protocol for which a formal definition exists.
  • You can use either web-aware application programs or non-web-aware applications with a converter program to provide responses to requests. You can handle requests and responses using certain elements of the EXEC CICS WEB programming interface or pass them between CICS applications in a COMMAREA.
  • The web error program DFHWBEP provides an error response if an abend occurs in the analyzer program, converter program, or user-written application program, and also if the analyzer program and converter program cannot determine which application program will service the request. The standard HTTP error messages are used by default, but you can tailor them if required.
Some CICS web support facilities are not available for non-HTTP requests:
  • Some of the facilities that help you interpret HTTP requests and construct the responses are not available. For example, message headers cannot be accessed separately.
  • The enhancements introduced in CICS TS Version 3, including chunked transfer-coding, are generally not available to non-HTTP requests.
  • Persistent connections are not supported.
  • URIMAP definitions are not used for non-HTTP requests.

The support that CICS web support provides for non-HTTP messages is not the same as the TCP/IP Sockets interface for CICS. The z/OS® Communications Server IP CICS Sockets interface provides an application programming interface to allow clients to communicate directly with CICS application programs over TCP/IP. CICS web support is not part of this process.

The CICS Sockets interface is supplied with z/OS Communications Server, not with CICS. z/OS Communications Server: IP CICS Sockets Guide, SC31-8807, describes the CICS Sockets interface.