Improving the emand-Priori ty Pro tocol

The demand-priority protocol currently in the process of standardization by IEEE 802. I2 aims at supporting interactive multimedia applications by providing a low latency service for high-priority traffic. This goal may be achieved in case of large frames and/or small distances. Otherwise, improvements are required. This paper starts with a brief description of basic characteristics of the network topology and the medium access control protocol. Then, it presents simulation results for normal and high priority traffic in scenarios with variable bit rate high priority loads for networks of different sizes. It reveals the drawbacks of the demand-priority protocol and clearly shows the advantages of using service strategies different from those included in the current version of the draft standard.

[1]  Peter Martini,et al.  Measurements in a FDDI workstation cluster , 1994, Proceedings of 19th Conference on Local Computer Networks.

[2]  Russell J. Clark,et al.  Book Review: FDDI Handbook: High Speed Networking Using Fiber And Other Media, by Raj Jain (Addison-Wesley 1994) , 1994, CCRV.

[3]  Peter Martini,et al.  Real-time communication in the demand-priority LAN-the effects on normal priority traffic , 1995, Proceedings of 20th Conference on Local Computer Networks.

[4]  F. Ross,et al.  FDDI - A tutorial , 1986, IEEE Communications Magazine.

[5]  Markus Rümekasten.  Simulation of heterogeneous networks , 1994, WSC '94.

[6]  Peter Martini.  Connection Oriented Data Service in DQDB , 1994, Comput. Networks ISDN Syst..