Traffic Measurements in Data Networks, Recent Measurement Results, and Some Implications

Traffic statistics are a necessary base for network modeling, performance analysis, and network traffic control. This paper deals with results of recent traffic measurements in teleprocessing systems and their implications. In the introductory sections the range of traffic measurement problems in present networks and publications in the field of measurement results are surveyed. The main parts focus on measurement objects, results, and implications of recent user traffic measurements in four conversational teleprocessing systems, mostly with medium-speed terminals like cathode ray tube (CRT) display terminals. The first two moments, distributions, and regressions of random variables characterizing the structure of dialog cycles are presented. Some important properties are extreme traffic burstiness, frequently high coefficients of variation, and different characteristics of CRT terminals compared with teletypewriters. It is observed that new measurement tasks are arising and improved measurement systems are needed.