Network switch with arbitration sytem

摘要

A local area network switch includes a set of input ports each receiving and storing incoming packets from a corresponding network station, a set of output ports each forwarding packets to a corresponding network station, and a switching system for routing packets from the input ports to the output ports. The output ports are interconnected to form an output token passing ring and the input ports are interconnected to form an input token passing ring. Whenever an idle output port receives the output token, it holds the output token and signals the input ports to start an input token passing cycle. During an input token passing cycle, an input port storing a packet destined for an output token holder terminates the input token passing cycle when it receives the input token and signals the switching system to establish a connection to the output token holder. To fairly distribute arbitration priority, input and output ports starting positions are rotated for successive input and output token passing cycles.