Outbound side information

APPC/MVS side information supplies destination information, such as the name of the partner program, the name of the LU at the partner node, and the logon mode name.

CPI Communications provides a way to use system-defined values for these required fields; these system-defined values are the side information. This information can be used by an IMS application program allocating (establishing) an APPC conversation using CPI Communications, an IMS LU 6.2 descriptor, a DL/I change call (CHNG), or a DFSAPPC message switch.

System programmers supply and maintain the side information for CPI Communications programs.

Side information is accessed by a symbolic destination name. The symbolic destination name, called sym_dest_name within the context of administering IMS TM, corresponds to an entry in the side information file containing the following information:

partner LU name: Shows the name of the LU where the partner program is located. This LU name is any name for the remote LU that is recognized by the local LU for allocating a conversation. An example is a USERVAR name.
This LU name can be a 17-byte network-qualified LU name.
logon mode name: Used by LU 6.2 to designate the properties for the session that will be allocated for the conversation. The properties include the class of service to be used on the conversation. The network administrator defines a set of mode names used by the local LU to establish sessions with its partners. The system programmer uses one of these values in a side table entry. An invalid mode name prevents a conversation from being allocated.
TP name: Transaction program (TP) name specifies the name of the remote application program.

IMS and z/OS® do not accept blank sym_dest_name values on the Initialize_Conversation call.

The default name for the side information file is SYS1.APPCSI. Define this file in the SYS1.PARMLIB(APPCPMxx) as shown in the following example.

SIDEINFO
     DATASET(SYS1.APPCSI)

The destination name, partner LU name, mode name, and TP name can be defined using the APPC/MVS Administration utility (ATBSDFMU) as shown in the following example.

SIADD
     DESTNAME(DESTX)
     TPNAME(LU62USER_TPX)
     MODENAME(APPCMODE)
     PARTNER_LU(APPCLUX)

Related reading: For more information on APPC calls, see CPI Communications Specification.