Patent ID: 6337860
Filing Date: 2002-01-08
Classification: H04L

Abstract:
A switch comprising at least two switching planes, each having inputs and outputs, between which cells are switched to provide a cell stream on each of the outputs of each plane, a redundancy terminating unit being connected to only one output of each plane for receiving parallel cell streams from each connected output and comprising a selector unit selecting one cell at a time from one of the parallel cell streams, wherein the selector unit is arranged to select a cell substantially at random from one of the parallel cell streams; andwherein the switch is for switching cells which are either unicast cells or multicast cells, the unicast cells being switched in an ordinary way to an output of each switching plane and the multicast cells being switched to a group of outputs of each switching plane, characterized by a buffer memory in the redundancy terminating unit connected to receive multicast cells from the outputs of the planes which are connected to the redundancy terminating unit, the selector unit being arranged to select a cell among unicast cells received each time and one cell stored in the buffer memory.