To benefit from the cross-memory support provided by SDT, you must be running with SDT support in both the requesting and serving CICS® systems. This means that each system must be at least a CICS/ESA 3.3 system with the SDT feature installed.
If only the requesting CICS system has SDT support, there is no effect apart from the very small overhead of occasional attempts to determine whether the server system supports sharing. All requests continue to be function shipped.
If only the serving CICS system has SDT support, all requests continue to be function shipped by the requester. The requester does, however, obtain the benefits of local data table accesses made by the server.