Abstract: The swapping function of input values to output values is performed through a pseudo content addressable memory which provides output values corresponding to a number E of n-bit input values, with E=2p−1. The pseudo content addressable memory is made of a plurality of cascaded random address memories 20 having at least a 2d addressing capability, with d higher than p. A control logic circuit is provided to store into each random access memory p-bits pointers, with each pointer being different from the others and randomly assigned to an input value.

Abstract: This invention is an implementation of a congestion control mechanism, especially for ATM networks supporting data services or other nonreserved bandwidth traffic, e.g. in multimedia applications. It reacts immediately upon detection of a traffic bottleneck by selectively and temporarily holding back the data traffic that is to pass the bottleneck (5). A congested node (3) transmits congestion notifications (36) containing routing label information and deferment information to upstream nodes (2), thus enabling selective, temporary throttling action. If congestions persist, further notifications may be spread backwards step by step, eventually reaching the sources. A specific implementation is given for PRIZMA type switching nodes.

Abstract: This invention is an implementation of a congestion control mechanism, especially for ATM networks supporting data services or other nonreserved bandwidth traffic, e.g. in multimedia applications. It reacts immediately upon detection of a traffic bottleneck by selectively and temporarily holding back the data traffic that is to pass the bottleneck (5). A congested node (3) transmits congestion notifications (36) containing routing label information and deferment information to upstream nodes (2), thus enabling selective, temporary throttling action. If congestions persist, further notifications may be spread backwards step by step, eventually reaching the sources. A specific implementation is given for PRIZMA type switching nodes.

Abstract: A node for an access control system for a multi-channel data transmission ring is disclosed. Access to a channel is controlled exclusively by one node, which is the only data receiving node connected to that channel. The receiving node generates slots so that other connected nodes can transfer data to the receiving node. The receiving node can provide balanced access to the channel by all connected nodes. Further embodiments feature prevention of congestion in the buffer of the receiving node. The invention is particularly useful for wavelength division multiplexed (WDM) optical rings.

Abstract: This invention comprises a telephone hybrid circuit having two opto-coupler arrangements for transferring voice signals from the two-wire line to a port of the switching system on one hand and from a port of the switching system to the two-wire line on the other hand. In addition, a pair of feeder circuits in the form of current sources comprising active elements are provided for feeding a constant positive direct current to one wire of the two-wire line and a negative direct current of equal magnitude to the other wire of the two-wire line. Each of the current sources includes control circuitry for maintaining a constant ratio between the current furnished by the current source and a control current common to both current sources. A control current path is connected to the output of one of the opto-coupler arrangements for generating a common control current in response to a dc signal and a superimposed voice signal received from a port of the switching system.