In addition to having a sysidnt for itself, a CICS® system requires a sysidnt for every other system with which it can communicate. Sysidnt names are used to relate session definitions to system definitions; to identify the systems on which remote resources, such as files, reside; and to refer to specific systems in application programs.
Sysidnt names are private to the CICS system in which they are defined; they are not known by other systems. In particular, the sysidnt defined for a remote CICS system is independent of the sysidnt by which the remote system knows itself; you need not make them the same.
The mapping between the local (private) sysidnt assigned to a remote system and the applid by which the remote system is known globally in the network (its netname), is made when you define the intercommunication link. For example:
DEFINE CONNECTION(sysidnt) The local name for the remote system
NETNAME(applid) The applid of the remote system
Each sysidnt name defined to a CICS system must be unique.