ON THE EFFECTIVE TRAFFIC CONTROL OF ABR SERVICES IN ATM NETWORKS

Although ATM networks support various traffic requirements, but many d ata applications are unable to precisely specify traffic parameters su ch as bit rate. These applications generally require a dynamic share o f the available bandwidth among all active connections, they are calle d available-bit-rate (ABR) service. Due to bursty and unpredictable pa ttern of an ABR data stream, its traffic control is more challenging t han other services. In this paper, we present an improved ABR traffic control approach, called Offset Proportional Rate Control Algorithm (O PRCA). The proposed approach achieves high link utilization, low delay and weighted fair sharing among contenting sources according to the p redefined OPR. The implementation is much simpler than that of existin g schemes. OPRCA combines an end-to-end rate control with link-by-link feedback control, and employs a buffering scheme that avoids Head-of- Line (HOL) blocking. It can dynamically regulate the transmission rate of source traffic and maintain the real fairness among all active con nections. Simulation results have shown the effectiveness of OPRCA in several performance aspects.