We develop a new class of asynchronous distributed algorithms for the explicit rate control of elastic sessions in an integrated packet network. Sessions can request for minimum guaranteed rate allocations (e.g., MCRs in the ATM context), and, under this constraint, we seek to allocate the max-min fair rates to the sessions. We capture the integrated network context by permitting the link bandwidths available to elastic sessions to be stochastically time varying. The available capacity of each link is viewed as some statistic of this stochastic process (e.g., a fraction of the mean, or a large deviations Equivalent Service Capacity (ESC)). For fixed available capacity at each link, we show that the vector of max-min fair rates can be computed from the root of a certain vector equation. A distributed asynchronous stochastic approximation technique is then used to develop a provably convergent distributed algorithm for obtaining the root of the equation, even when the link flows and the ...

An important concept in the ABR service model is the minimum cell rate (MCR) guarantee as well as the peak cell rate (PCR) constraint for each connection. Because of the MCR and PCR constraints, the classical maxmin policy no longer suffices to determine rate allocation since it does not support either the MCR or the PCR.

A significant portion of the traffic in packet data networks is from store-and-forward sessions. Such traffic flows are elastic, i.e., they can adapt to the transfer rate that the network can provide them. The network reserves bandwidth for real-time sessions, such as interactive voice, and dynamically shares the remaining bandwidth among the elastic sessions, in order to achieve some bandwidth sharing objective, such as max-min fairness. A distributed algorithm is required for this purpose. Several distributed algorithms for max-min fair rate allocation are available in the literature [9],[15], [16],[6]. The underlying assumption in these algorithms has been the availability of a fixed available capacity on each link for an extended period of time. However, in practice the available capacity will have rapid fluctuations due to the intrinsic rate variations of the guaranteed bandwidth flows. In this paper we develop an approach based on the distributed stochastic approximation algorith...

An important concept in the available bit rate (ABR) service model as defined by the ATM Forum is the min- imum cell rate (MCR) guarantee as well as the peak cell rate (PCR) constraint for each ABR virtual connection (VC). Because of the MCR and PCR requirements, the well-known max-rain fairness policy no longer suffices to determine rate allocation in the ABR service model. We introduce a network bandwidth assignment policy, MURadd, which supports both the MCR and PCR requirements for each ABR virtual connection. A centralized algorithm is presented to compute network-wide bandwidth allocation to achieve this policy. Further- more, an explicit-rate (ER) based ABR switch algo- rithm is developed to achieve the MCRadd policy in the distributed ABR environment and its convergence proof is also given. The performance of our ABR algorithm is demonstrated by simulation results based on the benchmark network configurations suggested by the ATM Forum.