Optimal buffer control during congestion in an ATM network node

A b s t r a c t In t.his paper we study the problem of optimal Ijuffer space priority control in an ATM network node. 'l'lie bulfer of a transmission link is shared among the cclls of several traffic classes waiting for transmission t.lirough t,he link. When the number of cells to be st,ored in the buffer exceeds the available buffer space, ccr ia i i i cells have to be dropped. Different traffic classes have different sensitivities to cell losses. By a.ppropriately selecting the classes of cells which are dropped in case of overflow, we can have the more sen-sit.ive classes suffer smaller cell losses. Arriving cells rnight. be blocked from entering the system or they rr1a.y be dropped after they are already in the buffer. Ilel~ending on the control that we have on the system, t.tiree classes of policies are distinguished. In each one, policies that schedule the buffer allocation in some op-t irnal manner are identified. 1