Voice and data performance measurements in L-express net

ABSTRACT

L-Express is a protocol for Local Area Networks based on a single bus topology. It utilizes a simple and efficient virtual token access scheme which provides ordered and collision-free transmission. This paper presents results of measurements performed to investigate in details the behavior of the L-Express protocol under different network speeds, configurations and traffic environments. The measurements are obtained using a mix of simulation and field tests on a network prototype. Voice and integration of voice and data are also taken into account. The results indicate a good behavior (compared with Ethernet) for small size networks (500 m) and Low data rates (10 Mb/s) as well as for Large size networks (5000 m) and high data rates (100 Mb/s).

REFERENCES

• 1: F.Borgonovo, L.Fratta,F.Tarini, P.Zini, "L-Express Net :The Communication Subnetwork for the C-NET Project", in Transactions on Communications, ed. IEEE (July 1985)
• 2: Consiglio Nazionale delle Ricerche, Distributed Systems on Local Networks, Pisa (June 24-28 1985)
• 3: Digita l, Intel, Xerox, The Ethernet : Data Link Layer and Physical Layer Specifications, Version 1 .0 (September 30, 1980)
• 4: T. P. Brady, "A Techniquefor Investigating On-off Patterns of Speech", Bell System Technical Journal (January 1965)
• 5: Musser J.M. , Liu T.T.,Li L. , Boggs G.J., "A Local Area Network as a Telephone Local Subscriber Loop", in Journal on Selected Areas in Communications, ed. IEEE, vol. SAC~,, n. 6, pp. 1046 (December 1983)
• 6: R.Marcogliese, M. Pezze',S. Pi razzini, "The Behavior of L-Express Computer Communication in C ompa ri son with the rnet ", Proceedings on "Distributed Systems on LocalNetworks",Pisa,Italy (June 24-28, 1985)

INDEX TERMS

Classification:
  B. Hardware
  B.4 INPUT/OUTPUT AND DATA COMMUNICATIONS
      B.4.2 Input/Output Devices
          Subjects: Voice
  B.7 INTEGRATED CIRCUITS
      B.7.3 Reliability and Testing**
          Subjects: Testability**

  C. Computer Systems Organization
  C.1 PROCESSOR ARCHITECTURES
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.5 Local and Wide-Area Networks
          Subjects: Buses

General Terms:
Measurement, Performance, Standardization