Switching element with multiple operating modes and switching network incorporating a plurality of such switching elements, in particular for switching asynchronous time-division multiplex packets

Switching network comprising

• a plurality of input ports,
• a plurality of output ports,
• a plurality of switching elements arranged in a plurality of interconnected switching element stages, each switching element having inputs and outputs and means for transferring a packet received on one of its inputs to one or more of its outputs in accordance with routing data associated with said packet, the input ports of the network corresponding to the inputs of switching elements of a first stage and the output ports of the network corresponding to the outputs of the switching elements of a final stage,
• wherein all the switching elements of at least one stage of said switching network are each in the form of a switching element with a plurality of modes of operation and comprising
• at least one input,
• a plurality of outputs,
• selective retransmission means for retransmitting a packet received on said at least one input to one or more of the outputs on a basis of routing data associated with said packet, said selective retransmission means having a plurality of modes of operation, and
• retransmission control means for determining one of the modes of operation of said selective retransmission means, said retransmission control means comprising
• direct routing means for receiving from a label of a packet received on said at least one input, a destination indication and for using a fixed routing algorithm to decode the destination indication into a single output identifier corresponding to at least one of the outputs in order to retransmit the packet to an output designated by said output identifier,
• translated routing means for receiving from the label of the packet received on said at least one input, a virtual circuit reference number and for using virtual circuit data temporarily stored in a translation memory to translate the virtual circuit reference number into one or more output identifiers each corresponding to at least one output, for retransmitting the packet to one output for each output identifier designated by said one or more output identifiers,
• a non-selective routing means in which a particular one or more outputs to which the packet is retransmitted is selected independently of any destination identification or virtual circuit reference numbers included int he received packet, and
• routing mode selector means for receiving routing mode data included in the label of a packet received on said at least one input for selectively commanding in accordance with the received routing mode data the use of a routing device selected from the group comprising said direct routing means, said translated routing means, and said non-selective routing means.