A 3-stage switching system is provided for generating, i.e. finding, reserving and setting, path from one switch entrance port (1) to at least one switch exit port (transmit side) for asynchronously received and buffered data cells. While an Nth cell is being transferred, control means (36) generate a control word including the switch exit port address for cell (N+1)th to be subsequently transferred. Said control word is used to find and reserve a path through the switch on a stage-by-stage basis, and then set said path, if any, using a fed back acknowledgement. The (N+1)th cell path generation is performed during cell N transfer, on a cycle stealing basis.