Proposal of a resource reservation-type data transfer protocol providing high QoS for reserved data on LAN

For the purpose of realizing a bandwidth reservation mechanism on LAN, we e arlier proposed a resource reservation type data transfer protocol that map s data reserved by Resource ReSerVation Protocol (RSVP) onto the synchronou s bandwidth of Timed Token Protocol (TTP), which is the MAC protocol of FDD I, and evaluated its Quality of Service (QoS) by simulations on a LAN model where reserved data from the upper layer arrive at LAN nodes with a Poisso n distribution. By simulations, we confirmed the effectiveness of the bandw idth reservation mechanism by showing that the data transmission rate of re served data stays 100% within the reserved bandwidth. The protocol, however , had no function to process excess data that arrive at LAN nodes earlier t han the timing determined by the reserved bandwidth. As a result, the data transmission delay time of reserved data increased greatly when the average load of reserved data was close to the reserved bandwidth. In this paper, we study several methods for processing the excess data to s olve the above-mentioned problem and propose another resource reservation-t ype data transfer protocol that provides high QoS for reserved data using o ne of the methods. We also evaluate the effectiveness of the protocol by si mulations. (C) 2000 Scripta Technica.