Resilient Packet Ring（RPR） is a new data transport technology of Metropolitan Area Networks （MAN）. One of the key techniques of RPR is ring distributed fairness algorithm. The task of the fairness algorithm is to ensure that all stations get their fair share of the bandwidth

when there is more demand than supply. This paper discusses how the RPR fairness algorithm is able to divide the bandwidth fairly among contending stations and how fairness algorithm make the link rate converge to the fair value. Finally we show that the setting of the RPR IpCoef configuration parameter is of crucial importance for the convergence of the fairness algorithm.