Abstract: A method and apparatus (1) is disclosed for switching data packets. A data packet is received from an input interface device (7) at one of a plurality of initial input ports (6). The data packet is divided into plural smaller data fragments. Each data fragment is passed to a respective one of a plurality of slices of an input port (3) of a core switch (2). The data fragments are switched using the core switch (2) so as to pass each data fragment to a selected respective one of a plurality of slices of an output port (3) of the core switch (2). The data fragments are then passed to a selected one of a plurality of ultimate output ports (5?). The data fragments are assembled to reform the data packet, and the reformed data packet is transmitted to an output interface device (7) connected to said selected one of a plurality of ultimate output ports (5?).