IMS-to-IMS TCP/IP connections
TCP/IP connections between two IMS™ systems are defined by IMS Connect configuration statements and other IMS system definition macros or PROCLIB members that are required by the IMS communications component that uses the TCP/IP connection.
Each defined connection between two IMS Connect instances supports sending primary communications messages only one way. To establish a TCP/IP connection from the remote IMS system back to the local IMS system, a separate TCP/IP connection must be defined from the remote IMS system back to the local IMS system.
A complete connection between two IMS systems has three sections:
- The connection between the sending IMS system and the sending IMS Connect instance. This section is not a TCP/IP connection, but rather a communications method managed by either the Structured Call Interface (SCI) of an IMSplex or the z/OS® cross-system coupling facility (XCF). IMS Multiple Systems Coupling (MSC) communications uses SCI. IMS Open Transaction Manager Access (OTMA) communications uses XCF.
- The connection between the sending and receiving IMS Connect instances. This section is a TCP/IP connection.
- The connection between the receiving IMS Connect instance and the receiving IMS system. This section is managed by either SCI or XCF.
Depending on whether the TCP/IP connection is used for MSC or OTMA communications, the steps for defining the connection differ.
The following figure shows an example IMS-to-IMS TCP/IP communications configuration.