A high-performance MAC protocol for client-server-based gigabit LANs/MANs

Advances in network technology and the emergence of applications requiring stringent quality of service (QoS) requirements have made the design of gigabit LANs/MANs indispensable. Unlike existing LANs/MANs, gigabit LANs/MANs exhibit high delay-throughput product. Moreover, forthcoming networks are required to support diverse nodes demanding different amounts of bandwidth. Examples are networks with multimedia workstations and with client-server configurations. These facts render traditional MAC protocols unavailable. This paper proposes a high-performance MAC protocol, called prioritized adaptive cycle cell insertion (PACCI), especially advantageous to client-server-based gigabit LANs/MANs. PACCI achieves bounded delay and high utilization regardless of the network size and load. In addition to providing fair access for regular nodes (e.g., clients) through regular cycles, PACCI offers prioritized access to privileged nodes (e.g., servers) through restricted cycles. The bandwidth allocation of the regular and restricted cycles is based on an analytic model in an effort to provide QoS guarantees in terms of normalized throughput under diverse traffic loads. The paper also presents simulation results that demonstrate the accuracy of the analysis and the superior performance of PACCI.