Coordinating IMS definition and network definition
Provide input to VTAM® and NCP regarding the network requirements described in the following topics.
Using IMS as a host subsystem
You must define the IMS control region to VTAM as an application. Your installation needs to decide on a name. This name is used in the definition of application nodes that are added to the SYS1.VTAMLST system data set.
Defining VTAM nodes
The local node names are also added into SYS1.VTAMLST.
Estimating VTAM storage requirements
Examine the full set of terminal options that are planned for the IMS network and select those communication options that might have an effect on the VTAM storage requirements.
Determining VTAM buffer pool values
Provide the VTAM system programmer with IMS input and output message sizes. The values you select for the number and size of receive-any buffers, as specified on the RECANY keyword of the COMM macro, are of special importance.
Determining the NCP buffer pool values
The NCP buffer pool sizes and thresholds are based on the VTAM buffer pool information.
Determining static and dynamic terminal signon requirements
All VTAM-defined terminals can sign on by providing user data with the session initiation request, regardless of whether signon is required for the terminal.
Checking requirements for LOGON MODE tables
When a static VTAM terminal is connected to IMS and a session is initiated, VTAM needs to know the LOGON MODE identifier.
Specifying initial VTAM configurations
Based on your IMS requirements, start lists (ATCSTRyy) and configuration members (ATCCONxx) are placed in the SYS1.VTAMLST library. This information should reflect those terminals that are to be activated at VTAM startup, and those VTAM nodes that are known to VTAM at startup.
Using SON/COS support in IMS
Session outage notification (SON) and class of service (COS) are facilities of VTAM and SNA that allow IMS to recognize a session outage.
Parent topic:
Defining the network