International Business Machines Corporation

Mark Verhappen

Francois Abel

Mitch Gusat

Cyriel Johan Minkenberg

Ronald Pete Luijten

Antonius Paulus Engbersen

Ferdinand Gramsamer

Alan Frederic Benner

Alain R Blanc

Michel Poret

Norbert Schumacher

Wolfgang Emil Denzel

Michel Colmant

Jose Duato

Michael Colmant

The present invention discloses a memory sharing mechanism based on priority elevation. In accordance with the present invention, there is provided an apparatus and method for transporting packets of data in a communication device, wherein each packet is assigned one of several priorities and received based on memory state information. The method comprises the steps of storing the received packets in a memory and modifying the assigned priority of any of the packets causing congestion within the memory.

Memory sharing mechanism based on priority elevation

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

For switching or transmitting data packets, one can provide communication systems which consist of several modules &#x2014;operating in parallel on segments of a packet &#x2014;to increase speed and handling capacity. One module acts as master, others are slave modules controlled by control signals derived by the master module. It is important to correctly synchronize in each module the data segment and the respective control signal of each packet, 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 synchronization in master-slave distributed communication systems

The present invention discloses a scalable flow-control mechanism. In accordance with the present invention, there is provided a switching device for transporting packets of data, the packets being received at the switching device based on flow-control information, the device comprising a memory for storing the packets, a credit counter coupled to the memory for counting a credit number of packets departing from the memory, and a scheduler unit coupled to the credit counter for deriving the flow-control information in response to the credit number. Moreover, a switching apparatus and a method for generating flow-control information is disclosed.

Scalable link-level flow-control for a switching device

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Zurich, Switzerland

Mark Verhappen