Patent ID: 7843942

Claim:
A node for calculating a fair rate indicative of a predetermined upper limit value for a communication band, said fair rate being defined for a fairness controlled traffic packet having the communication band controlled to the upper limit value or less, for transmission to other nodes of a communication system to which said node belongs, said node comprising: a traffic rate measuring unit for measuring a communication band of the fairness controlled traffic packet sourced from said node, and a communication band of the fairness controlled traffic packet which passes through said node; and a fairness control unit for calculating the fair rate by dividing a communication band available for a transmission of the fairness controlled traffic packet, found using the communication band of the fairness controlled traffic packet sourced from said node and the communication band of the fairness controlled traffic packet which passes through said node, by the number of nodes which transmit the fairness controlled traffic packet using a link on which congestion occurs, wherein said fairness control unit is configured to: subtract a communication band of band guaranteed traffic packet having a guaranteed communication band, from a communication band of a link which connects an adjacent node and said node; calculate a communication band available for a transmission of the fairness controlled traffic packet by further subtracting the sum of a communication band of the band guaranteed traffic packet sourced from said node and a communication band of the band guaranteed traffic packet which passes through said node from the resulting difference; and calculate the sum of the communication band of the band guaranteed traffic packet sourced from said node and the communication band of the band-guaranteed traffic packet which passes through said node from a communication band measured by said traffic rate measuring unit.