International Business Machines Corporation

Michel Colmant

Cyriel Johan Minkenberg

Alan Frederic Benner

Alain R Blanc

Francois Abel

Michel Poret

Mitch Gusat

Norbert Schumacher

Antonius Paulus Engbersen

Ferdinand Gramsamer

Mark Verhappen

Marco Heddes

Ronald R Luijten

Marinus J Van Weert

A communication system which consists of several modules&#x2014;operating in parallel on segments of a packet&#x2014;to increase speed and handling capacity. One module acts as master, the others are slave modules controlled by control signals derived by the master module. It is important that in each module the data segment and the respective control signal of each packet are correctly synchronized, because in large systems the data paths carrying packet segments and the control signal paths may have substantially different delays. The invention provides for measurement of the propagation delay differences and for introducing a controlled delay in each slave module, so that data segments and control signals can be correctly correlated by delaying either the one or the other. Synchronization packets are transmitted besides normal data packets, for obtaining time stamps which are used to determine the delay difference.

Method and arrangement for local sychronization in master-slave distributed communication systems

The present invention relates to switching in electronic networks. Many data transmission protocols and technologies used in such networks, such as TCP/IP and Ethernet, use variable-length packets for transmission. Often however, the nodes that make up these networks typically contain high-speed cell switches that only support fixed-size data units. To support variable-length packets in such a fixed-size cell switch non-interleaving switching and transmission must be offered. The present invention provides such a solution in essence by segmenting a variable-length frame into a plurality of fixed-length cells including a start-of-frame cell, one or more continuation cell(s), and an end-of-frame cell and routes said fixed-length cells through said switch, thereby providing, at an output of said switch, subsequent and deadlock-free transmission of consecutive cells of a certain frame, and block any cell of a different frame from interleaving. This leads to better average delay characteristics and removes the need for packet reassembly.

Method and structure for variable-length frame support in a shared memory switch

A switching device comprising several input ports and several output ports, whereby each of the input ports is connectable to a corresponding switch adapter. At least one switch controller controls the routing of incoming data packets from the input ports to the output ports. For each output port a congestion controller is arranged which in operation, generates grant information which signals whether the switch adapters are allowed to send the data packet to the output port. For each of the input ports a data packet access controller marks a data packet as non-compliant if the packet was erroneously sent from said output port.

Switching device and method for controlling the routing of data packets

Fast routing and non-blocking switch which accomodates multicasting and

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Erlenbach, Switzerland

Michel Colmant