International Business Machines Corporation

Cisco Technology, Inc.

Jocelyne Jaumes

Maurice Cukier

Michel Poret

Daniel Wind

Rene Gallezot

Thierry Roman

A network node supports switching fixed length information cells between a source unit and a destination unit. The invention uses two lookup tables called the active and the standby calendars for each of said output line. Each entry in the calendars represents the position of one cell in the output cell stream which will be sent onto said output lines. While the active calendar is controlling the network cell multiplexing onto a node output line, the standby calendar is updated at each traffic change by looking for a calendar free position for the new traffic starting with a targeted theoretical entry position. A Free Location Table (700) is used, storing the calendar organized by pages. The standby calendar updating starts with reading a Free Location Table page pointed at by the most significant bits of the theoretical entry. Should said page contain only ones (i.e., no free cell position) looking for the nearest page containing at least one zero (i.e., free cell position) and updating the Table and standby calendar accordingly, and then swapping calendars.

Method and an apparatus for shaping the output traffic in a fixed length cell switching network node

A protocol adapter for an Asynchronous Transfer Mode (ATM) cell switching system has a receive part and a transmit part, the receive part being arranged to convert an incoming ATM cell into a cell structured with a payload and a header including an output index (OI). The transmit part is arranged to convert the structured cell after it is routed through the switching system into an ATM cell, and to output the ATM cell on the ATM communication lines. The transmit part has cell processing logic for adding a bit (mother-bit) in the header of each incoming structured The output index of a mother cell is used to access a location in a look-up table which contains for each output index, a multicast bit for indicating whether the cell is to be multicasted or not, a queue index for indicating a location where to enqueue the cell before it is outputted from the transmit part, a new VP/VC/Li value for constructing a new header, and a next-output index. For the multicast cells, the queue index is replaced by a multicast-queue index in order to store the multicast cells in a dedicated multicast queue. When a multicast mother cell reaches the head of the multicast queue, one or more daughter cells are generated by duplicating the payload of the current mother cell but assigning a different destination address.

Method and system for multicasting cells in an ATM protocol adapter

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Pibrac, France

Jocelyne Jaumes