Method,
system and
computer program product, the product comprising a non-transitory computer readable medium retaining instructions, which when read by a processor, cause the processor to: execute
business logic applicable to first and second versions of a
telephone exchange system, wherein communication with the first / second version is performed using an object of a first / second class compatible with the first / second version and not with the second / first version, and wherein the
business logic is implemented using a universal object of a universal class comprising all fields and methods of the first and second classes; in response to determining to communicate with a first / second
system implementing the first / second version: transform the universal object into a first / second object; and transmit the first / second object to the first / second system; wherein the processor is part of a
computerized system that comprises a plurality of version-heterogenous
telephone exchange systems, including the first and the second
telephone exchange systems.