Patent ID: 6570873
Filing Date: 2003-05-27
Classification: H04L,H04Q

Abstract:
A system for scheduling a reservation of a traffic with a priority, wherein packets belonging to a high priority traffic are forwarded from an input port to an output port in accordance with the reservation, said system comprising:input ports, each of said input ports comprising: queues which input inputted packets while classifying said inputted packets by addressed output ports and priorities into said queues and output said inputted packets individually when receiving a grant signal; means for obtaining and outputting connection information including a request for reserving a connection of such input port with an addressed output port for packets belonging to the high priority traffic on the basis of signaling of the high priority traffic; and means for outputting a request for a connection of such input port with an addressed output port for a low priority packet; output ports which output packets received from said input ports; a switch which connects said input ports and said output ports; and a scheduler which controls said switch by a setting signal; wherein said scheduler comprises: a schedule generator which determines, on the basis of each request for reserving a connection which is received from one of said input ports, a value of each element of each of priority reservation allocation matrices which are provided for every time slot and have the numbers of said input ports as numbers of rows thereof and numbers of said output ports as numbers of columns thereof; a priority reservation table which stores said priority reservation allocation matrices for every time slot; a priority reservation reader which reads each of said priority reservation allocation matrices from said priority reservation table every time slot; a request matrix generator which determines, on the basis of said requests for connections which are received from each of said input ports, a value of each element of a request matrix, said request matrix having the numbers of said input ports as numbers of rows thereof and numbers of said output ports as numbers of columns thereof; a request matrix masking portion which masks said request matrix on the basis of each of said priority reservation allocation matrices which is read every time slot to generate a masked request matrix; a scheduling algorithm portion which performs scheduling on the basis of said masked request matrix in order to generate an allocation matrix; an allocation matrix multiplexer which adds said allocation matrix and said priority reservation allocation matrix together in order to generate a final allocation matrix; and an allocation matrix processor which generates said grant signal and said setting signal on the basis of said final allocation matrix.