In spite of the incompatibilities among networks, researchers have devised a function that gives universal service among heterogeneous networks known 'internetworking'. It uses both software and hardware.

PHYSICAL NETWORK CONNECTION WITH ROUTERS:

A router is a special purpose machine dedicated to the task of interconnecting servers. A router can interconnect servers that need different technologies including different media, physical addressing methods or message formats. A router connecting two physical servers is given in the figure below.