High Throughput of Asynchronous Traffic and Maximum Capacity of Synchronous Sources With the New Fddi's Mac Protocol

Abstract

It is well known that Fiber Distributed Data Interface (FDDI) offers an excellent cost-benefit and guarantees a reliable and powerful network. It is also fact that the FDDI is suitable for synchronous traffic because of the high speed and the performance guarantees it provides. However, these guarantees are achieved at the expense of asynchronous traffic because the synchronous messages are given highest priority over asynchronous messages, resulting in excessive delays and low throughput for asynchronous message. This paper, presents a modification of the FDDI's MAC(Media Access Control) protocol to control the maximum token rotation time not to exceed the TTRT (Target Token Rotation Time) in the worst case, the realization of this condition leads to set the TTRT to the message generation period (Tg) instead of one half of it (Tg/2). The new protocol of FDDI's MAC increasing both the throughput of asynchronous traffic and the capacity of synchronous sources. The proposed MAC is evaluated by means of computer simulation. The simulation results confirm that the new proposed MAC provides FDDI more efficient for supporting multimedia applications.