Abstract: A fastener for removably mounting a housing to a shelf includes a base having an upper surface and a lower surface adapted for connection to a bottom panel of the housing at an edge portion of the housing. The base includes a front edge and a portion extending from the front edge which is turned under the base and is disposed spaced apart from the base and adjacent to a lower surface of the base to form a spring clip. The clip engages an edge portion of the shelf between the lower surface of the base and the portion extending from the base front edge.

Abstract: An ATM data network switch having two separate but simultaneously active switch fabrics and a plurality of slot controllers is disclosed. Each slot controller has at least one external data link thereto and is separately connected to the two separate switch fabrics. Each switch fabric was the ability to switch a data cell transmitted from any one of the slot controllers to any of the other slot controllers. Each slot controller is arranged to determine the availability of the data paths to all the other slot controllers through both switch fabrics and to select for each cell to be switched a data path through one or the other of the switch fabric according to the availability determined.

Abstract: An ATM cell switch suitable for multicast switching comprises an input stage arranged to detect a multicast cell and to add to the cell header a switch header identifying the outputs to which copies are to be sent, a switch fabric arranged to identify multicast cells, to make identical copies thereof and to route the copies according to the switch header, and an output stage arranged to make further copies according to the data links which are to receive the multicast and to assign the appropriate VPI/VCI to the cell header of each copy according to data stored in said stage.