Interoperability testing
First of all understand what is interoperability: The ability of two computers to communicate & exchange information with each other.[Source]
Interoperability testing is defined as the assessment of the product to determine if it behaves as expected while interoperating with other product. However, interoperability testing is not enough. It only tests that a set of systems are interoperating. It does not guarantee that other systems interoperate with these systems. [Source]
Also See:
More on Interoperability