Assessment and alternative design of FDDI-II MAC protocol

Fiber distributed data interface-II (FDDI-II) is a hybrid high speed local area network (HSLAN) providing circuit switched and packet switched services. Although the packet switched service remains connectionless, the circuit switched service is connection-oriented. The weaknesses of the media access control (MAC) protocol of FDDI-II is discussed. A new access scheme, called FDDI-II*, aimed at providing distributed control and access of bandwidth using connectionless service for both packet and isochronous data transmissions is proposed. Simulation results that demonstrate the performance superiority of FDDI*-II to FDDI-II in terms of isochronous data blocking probability and packet data delay are presented.