Introducing the Natural Web I/O Interface Server CICS Adapter

This document describes the purpose and the functions of the Natural Web I/O Interface Server CICS Adapter.

The following topics are covered:

Purpose of the Natural Web I/O Interface Server CICS Adapter

The Natural Web I/O Interface Server CICS Adapter is designed for a mainframe Natural context where it enables the use of a Natural Web I/O Interface server, running under z/OS in batch mode within a CICS TP monitor environment.

CICS Support

The CICS support is not implemented within the front-end stub NATRNWO. For dispatching the Natural sessions in CICS, the Web I/O Interface server continues to run in batch mode or under SMARTS. But it uses the remote front-end NATCSRFE that is delivered with the Natural Web I/O Interface server to dispatch the Natural sessions in CICS. That is, depending on the installed front-end, a server dispatches the sessions locally (NCFNUC for SMARTS, NATMVS for batch mode) or remotely (NATCSRFE for CICS).

NATCSRFE in turn accepts the Natural request from NATRNWO and transfers it to a configured CICS environment using the CICS Socket Interface. Within the CICS environment, a CICS Natural transaction is launched that processes the Natural request and returns the result. Thus it is not necessary to execute the entire Web I/O Interface server under CICS. Only if Natural is requested to run the Natural application, control is transferred to CICS for execution.

The Natural Web I/O Interface Server CICS Adapter comprises the following components:

NATCSRFE The remote front-end called by the Natural Web I/O Interface server to dispatch a Natural request. It is loaded into the Web I/O Interface server's address space.
NATCNRFE The counterpart of NATCSRFE. NATCNRFE runs in the CICS address space. It is started by the IBM-provided standard listener of the CICS Socket Interface (refer also to TCP/IP V3R1 for MVS: CICS TCP/IP Socket Interface Guide).
NATSRGWO/NATLRGWO Transmits the data relevant for Natural Web I/O Interface server between Natural Web I/O Interface server and the Natural session running in CICS. NATSRGWO must be loaded into the Natural Web I/O Interface server's address space and NATLRGWO into the CICS address space.
NATUXRFE This user exit obtains the client credentials from the Natural Web I/O Interface server and authenticates then with a CICS VERIFY PASSWORD request. If the request succeeds, the CICS listener launches the NWO transaction under the client account (impersonation).

Product Interaction

The following figure illustrates the interaction between the Natural Web I/O Interface server and the CICS environment involved.

Interaction

  1. The Web I/O Interface (NWO) client sends a request to the Natural Web I/O Interface server using the port number specified with the Natural Web I/O Interface server configuration variable PORT_NUMBER.

  2. The Natural Web I/O Interface server dispatches the Natural session using the Natural front-end you have specified with the Natural Web I/O Interface server configuration variable FRONTEND_NAME. Specify NATCSRFE in order to use the Natural Web I/O Interface Server CICS Adapter.

  3. NATCSRFE transmits the request to the host/port specified with the Natural Web I/O Interface server configuration variable RFE_CICS_TA_HOST / RFE_CICS_TA_PORT. You must configure the CICS-supplied standard listener CSKL to listen at this port.

  4. If the Natural Web I/O Interface server is configured to perform remote impersonation (SECURITY_MODE=IMPERSONATE/IMPERSONATE_REMOTE), NATUXRFE is called to authenticate the client. If the authentication succeeds, CSKL launches the CICS transaction NRFE under the account of the client (impersonated).

  5. CSKL launches the CICS transaction you have specified with the Natural Web I/O Interface server configuration parameter RFE_CICS_TA_NAME (NRFE in this example). This transaction must be defined to use the program NATCNRFE.

  6. NATCNRFE finally dispatches the Natural session using the Natural CICS front-end you have specified with the Natural Web I/O Interface server configuration parameter RFE_CICS_FE_NAME.