Defining IMS-to-IMS TCP/IP connections for OTMA

Defining IMS-to-IMS TCP/IP connections for OTMA requires defining the destination for the ALTPCB output messages and defining the TCP/IP connection in IMS Connect.

An IMS-to-IMS TCP/IP connection delivers OTMA messages in only one direction. Any response messages are queued to a tpipe hold queue for asynchronous retrieval.

To send response messages or other transaction messages from the remote IMS installation back to the local IMS installation, a separate TCP/IP connection must be defined at the remote installation. The correlation of any response messages that are returned this way with the original transaction must be managed by your installation.

To define an IMS-to-IMS TCP/IP connection for OTMA messages:

Procedure

  1. For the local IMS Connect instance, define the IMS-to-IMS TCP/IP connection by coding the following required IMS Connect configuration statements in the IMS.PROCLIB data set of the local IMS installation:
    HWS
    This configuration statement is required by IMS Connect.
    TCPIP
    This configuration statement is required by IMS Connect.
    DATASTORE
    This configuration statement is required by IMS Connect for communication with OTMA.
    RMTIMSCON
    The RMTIMSCON statement defines the TCP/IP connection from the local IMS Connect instance to the remote IMS Connect instance.

    At a minimum, you must define the following keywords of the RMTIMSCON statement:

    ID
    Uniquely identifies this connection. The ID value must also be specified on the RMTIMSCON keyword on the OTMA destination descriptor.
    IPADDR or HOSTNAME
    Identifies the internet address of the receiving IMS Connect instance
    PORT
    Identifies the port that the receiving IMS Connect instance uses for this connection. This value must match the value specified on either the PORT or PORTID keyword in the TCPIP configuration statement of the remote IMS Connect instance.

    Optionally, specify the following additional parameters:

    APPL
    If the remote IMS Connect instance is configured to authenticate RACF® PassTickets (RACF=Y is specified on the remote HWS configuration statement), you must specify both the APPL and the USERID parameters.
    AUTOCONN
    Determines whether local IMS Connect automatically establishes the connection with the remote IMS Connect instance during startup.
    IDLETO
    Specifies the amount of time open socket connections can remain idle before they are terminated due to inactivity.
    PERSISTENT
    Defines the connection as persistent.
    Recommendation: Specify PERSISTENT=Y to reduce the usage of storage at the remote IMS installation. When persistent socket connections are used, less storage is used because the remote OTMA creates fewer tpipes.
    RESVSOC
    The number of send sockets that IMS Connect reserves for use by this connection.
    USERID
    If the remote IMS Connect instance is configured to authenticate RACF PassTickets (RACF=Y is specified on the remote HWS configuration statement), you must specify both the USERID and the APPL parameters.
  2. Code an OTMA destination descriptor in the IMS.PROCLIB data set of the local IMS system.
    At a minimum, you must code the following parameters:
    RMTIMS
    The name of the remote IMS system. The value specified on RMTIMS must match the name defined to the remote IMS Connect instance on the ID parameter of the DATASTORE statement at the remote installation.
    RMTIMSCON
    The name of the IMS-to-IMS TCP/IP connection to use, as defined on the ID parameter of the RMTIMSCON statement of the local IMS Connect instance.
    TMEMBER
    The z/OS® cross-system coupling facility (XCF) member name of the local IMS Connect instance, as specified on the MEMBER parameter of the DATASTORE statement of the local IMS Connect instance.
    TYPE
    Specify TYPE=IMSCON.

    In addition to the RMTIMS, TMTIMSCON, and TMEMBER parameters, specify any optional parameters in the OTMA destination descriptor.

  3. Optionally, specify the amount of time that OTMA waits for acknowledgements by coding an OTMA client descriptor with the T/O parameter.
  4. At the local IMS installation, modify the IMS application program that sends the transaction message to the remote IMS installation to:
    1. Specify the name of the OTMA destination descriptor as the destination when the application program issues the CHNG call.
    2. Issue an ISRT ALTPCB call to send the transaction message.
  5. Configure the remote IMS Connect instance by specifying the following required configuration statements:
    HWS
    To enable the remote IMS Connect instance to authenticate RACF PassTickets on incoming TCP/IP connections from the local IMS installation, specify RACF=Y.
    TCPIP
    The value specified on either the PORT or PORTID keyword of the remote TCPIP statement must be specified on the PORT keyword of the RMTIMSCON statement of the local IMS Connect instance.
    DATASTORE
    This configuration statement is used for communication with OTMA.
  6. Optional: Specify a RMTIMSCON statement for the remote IMS Connect instance if you need an IMS-to-IMS TCP/IP connection to send messages from the remote IMS installation back to the local IMS installation.