BETTER: handling best effort traffic in the ATM networks

This paper addresses the problem of handling best effort traffic (BET) in ATM networks. This type of traffic usually consists of information cell transfer without any guarantees about the quality of service. We show that its transfer characteristics strictly depend on the cell scheduling mechanisms used in the ATM switches. The comparative studies take into account the following queue disciplines: FIFO without priorities, FIFO within predefined priorities, weighted fair queuing algorithm and control by the cycle. The ATM services that handle BET traffic are ABR and UBR. A new way of handling BET traffic "best effort traffic takes empty round" (BETTER) controlled by a cycle mechanism is proposed. The outcome of the numerical study shows that BETTER has some advantages over other queuing mechanisms.