Virtual source/virtual destination (VS/VD) congestion control for multicast ABR services in ATM networks

Although in recent years, considerable efforts have been exerted on treatin g the congestion control problems of ABR services in the ATM networks, the focus has been so far mostly on unicast applications. The inclusion of the emerging multicast services in the design of congestion control schemes is still at its infancy. The generic rate-based closed-loop congestion control scheme proposed by the ATM Forum for ABR services suffers from large delay -bandwidth pr;,duct. VS/VD behavior is therefore proposed by the Forum as a n supplement. In this paper, two VS/VD behavior congestion control schemes for multicast ABR services in the ATM networks are examined forward explici t congestion notification (FECN) and backward explicit congestion notificat ion (BECN). Their performances are analyzed and compared. We further observ e that both VS/VD schemes alleviate the problem of consolidation noise and consolidation delay of the RM cells returning from the downstream nodes. Th e alleviation of consolidation noise and consolidation delay is a major con cern of most present researches. Simulation results are also given to suppo rt the validity of our analysis and claims.