Any CICS® Client can use the LU 6.2 (APPC) communication protocol to communicate with any CICS on System/390® server. Some CICS Client-CICS on System/390 combinations support the use of the Transport Control Protocol/Internet Protocol (TCP/IP). Support for TCP/IP is described in TCP/IP support.
CICS on System/390-CICS Client applications can use the APPC communication protocol. Single- or parallel-session connections can be used.
On CICS on System/390 systems, you can use autoinstall to define APPC connections to Clients dynamically, on their first use. You can autoinstall both single-session and parallel-session APPC connections. Alternatively, you can use the RDO CEDA DEFINE and INSTALL commands to define static connections to Clients.
APPC links to CICS Clients support data synchronization levels (sync levels) 0 and 1.
Client-CICS on System/390 TCP/IP communication is supported in two ways:
This section applies to:
This method requires IBM® TCP62 support to be installed on the Client workstation. TCP62 is a protocol mapper that enables partner APPC applications to communicate using TCP/IP. It extracts SNA definitions from the Client and uses them when communicating with CICS. The AnyNet feature of VTAM® is also required.
The System/390 servers supported are:
The Clients supported are those for:
Both the ECI and the EPI are supported.
For information about how to use TCP62 and AnyNet to set up a TCP/IP connection to a CICS Client, see Using TCP62 and AnyNet.
This section applies only to CICS Transaction Server for z/OS, Version 2 Release 2 and later.
This method allows Clients to use TCP/IP directly to CICS without any intervening products such as TCP62.
The only System/390 servers supported are releases of CICS Transaction Server for z/OS from Version 2.2 onwards.
All Clients are supported.
Only the ECI (not the EPI nor the ESI) is supported.
This is the preferred method of setting up TCP/IP connections between Clients and CICS on System/390, because:
For information about how to set up an ECI over TCP/IP connection to a CICS Client, see Using ECI over TCP/IP.