Multiregion operation

For CICS-to-CICS communication, CICS® provides an interregion communication facility that does not require the use of a network access method such as ACF/SNA or TCP/IP.

This form of communication is called multiregion operation (MRO). MRO can be used between CICS regions that reside:
  • In the same z/OS® image
  • In the same z/OS systems complex (sysplex).
CICS Transaction Server for z/OS can use MRO to communicate with:
  • Other CICS Transaction Server for z/OS systems
  • CICS Transaction Server for OS/390® systems
Note: The external CICS interface (EXCI) uses a specialized form of MRO link to support:
  • Communication between MVS™ batch programs and CICS
  • DCE remote procedure calls to CICS programs