PACKET SWITCH AND NETWORK

摘要

PROBLEM TO BE SOLVED: To avoid congestion and to attain improvement of network efficiency by autonomously changing a routing of a packet that passes on the basis of traffic information on plural output lines of a packet switch. SOLUTION: Traffic monitoring devices 9-1 and 9-2 measure a fluctuation during a time T of queue length of output buffers 82-1 and 82-2 respectively and detect their maximum value P (t) for each cycle T. According to P (t), P' (t)=αP(t)+(1-α)P'(t-T) is calculated. A header exchange part, which has a tag exchange circuit which is on further upstream of a packet switch on the up most stream and a header exchange table, compares the P'(t) with a threshold. When P'(t)>= the threshold, part of routing information is rewritten so that the output buffer 82-1 or 82-2 in which P'(t) becomes the minimum is routed, provided that 0<=α<=1 and P'(t-T) is a calculation result preceding t for T time.