Issues of congestion control and notification schemes in ATM networks and proposal of EPRCAM

In long haul networks, delay in congestion notification can cause an extended period of congestion which may in turn result in cell loss, and poor utilization of the network. In this regard we investigate various congestion notification strategies and show our results in this paper. Moreover, we identify deficiencies and problems associated with the enhanced proportional rate control algorithm (EPRCA) which is one of the explicit rate control algorithms recommended by the ATM Forum. These deficiencies cause unfairness in bandwidth utilization among contending sources. We suggest modifications in EPRCA and call it the modified enhanced proportional rate control algorithm (EPRCAM). We argue that EPRCAM will lead to better link utilization and fair bandwidth allocation between sources. In our simulation model, EPRCAM results in as high as a 97.5% link utilization without cell loss