Max-min fair rate control of ABR connections with nonzero MCRs

Traffic sources that do not have intrinsic temporal characteristics are expected to be transported over ATM networks using the available bit rate (ABR) service. These sources are amenable to reactive flow control and are expected to use bandwidth left over after servicing the guaranteed QoS services (CBR and VBR). Fair allocation of the available bandwidth to competing ABR connections is based on the concept of max-min fairness. The ABR service definition allows sources to specify a minimum cell rate (MCR) that is acceptable to them. Most studies of max-min fair rate allocation assume zero MCRs. In this paper, we first develop a natural extension of the concept of max-min fair rate allocation to the case of ABR sessions with nonzero MCR values. Then we present a centralised algorithm and discuss the construction of distributed algorithms for obtaining the max-min allocation. We show that the max-min allocation can be obtained as the solution of a certain vector equation, and discuss how such a perspective can help in designing stochastic approximation type algorithms for obtaining the max-min allocation when the available capacity is randomly varying