Abstract: An ATM signal processor system for processing ATM data cells which in combination define a data package wherein the last cell of a package is characterized by an identifying code. The cells of different data packages are multiplexed to provide a serial data stream. A server and a buffer store via which the server is fed with the serial data stream are provided. The buffer store has a threshold capacity beyond which cells are discarded. A discarded cell identifier/rejecter serves to identify and store the identity of a data package with which a discarded cell is associated so as to be set thereafter to reject subsequently received cells with the same data package identity until being reset upon receipt of the last cell of the package as indicated by its characteristic identifying code.

Abstract: A multicast server apparatus operative to effect the onward transmission of data cells to a plurality of different addresses includes a switch function unit having an input port, an output port and a transfer port, data cells for multicasting being routed from the input port and to the transfer port, first and second header translation units each having an input terminal and an output terminal. The translation units serve respectively as a chainer and as a distributor, the input terminals of the chainer and the distributor being coupled to the transfer port of the switch function unit to receive data for multicasting. The chainer is effective to change address data associated with each data cell fed thereto to a form recognizable by the distributor and to feed back such data cell together with its changed address data to the transfer port.

Abstract: A technique for interconnecting line processing units (LPUs) of a packet switch and/or data concentrator system in which, instead of using a standard bus system, each LPU has a number of duplex point to point serial links that are connected in either a random or structured manner to provide a network of routes between the LPUs. Information is then transferred between source and destination LPUs as short packets. When the system is expanded by adding more LPUs, the network of serial point to point links expands to provide more routes and, hence, greater bandwidth to handle the increased information flow. Failure of a link in the network is not catastrophic as there are a number of different routes to any LPU and the system only degrades systematically in the event of link failures.