Multipurpose packet switching node for a data communication network

For use in a data communication network having a plurality of nodes and a plurality of trunks for transporting fixed length packets and/or variable length (VL) packets between the nodes, a multipurpose switching node for switching fixed length or VL packets from any input trunk to any output trunk, said multipurpose switching node comprising:

• a) a multiport switching device having multiple inputs and multiple outputs, said switching device being capable of switching a fixed length cell having a predefined format received on any of said inputs to any of said outputs as a function of address information contained in the cell;
• b) one or more receive adapters, each being connected to one of the input trunks to the node and to one of the input ports of the multiport switching device, for receiving either fixed length packets or VL packets and each comprising:
• 1) a cell discriminator for identifying the format of each received packet,
• 2) a format converter connected to the input trunk and to said cell discriminator for converting each received packet to one or more fixed length cells, each having the predefined format,
• 3) means for directing each fixed length cell to an input port of said multiport switching device, and
• c) one or more transmit adapters, each being connected to an output port from said multiport switching device and to at least one output trunk and including means for receiving fixed length cells switched by said multiport switching device, each said transmit adapter further comprising:
• 1) means for detecting the desired format of the output packet which is to be based on the fixed length cell and the identity of the output trunk on which the packet is to be transported from the node,
• 2) a format converter for converting one or more of the switched fixed length cells to an output packet having the desired format, and
• 3) means for directing the produced output packet to the identified output trunk.