Administering CICS in a multiregion environment
If CICS® is operated in a multiregion environment, communication between regions can be supported by either multiregion operation (MRO) or intersystem communication (ISC).
Before you begin
About this task
You use MRO to support communication between two or more CICS regions running in the same MVS™ image. MRO also supports communication between separate MVS images within the same sysplex. MRO uses the CICS internal facilities and protocols and is entirely independent of SNA communications.
You use ISC to support communication between two or more systems in the same host, or to support communication in different hosts. ISC uses an SNA access technology such as ACF/SNA. The hosts can be different operating systems, and the communicating systems can be other than CICS. For example, a CICS region running in an MVS image can communicate with a CICS Transaction Server for VSE partition. Alternatively, on two MVS platforms, the communicating systems might be CICS and IMS.
For more information about operating CICS in a multiregion environment, see Multiregion operation.