Communication between systems

For communication between CICS® and non-CICS systems, or between CICS systems that are not in the same operating system or z/OS® sysplex, you usually require a network access method to provide the necessary communication protocols.

CICS TS for z/OS, Version 5.6 supports two such intercommunication facilities:
  1. Transmission Control Protocol/Internet Protocol (TCP/IP)
  2. ACF/SNA, which implements the IBM® Systems Network Architecture (SNA)
Communication between systems over TCP/IP is known as IP interconnectivity (IPIC). The generic name for communication between systems over SNA is intersystem communication (ISC) or intersystem communication (ISC) over SNA.

IPIC and ISC are used to connect CICS and non-CICS systems or CICS systems that are not in the same z/OS image or sysplex. These intercommunication facilities can also be used between CICS regions in the same z/OS image or sysplex. For example, you might create an ISC connection between two CICS regions in the same sysplex if you require two connections between them and there was already an MRO connection.