Measurements about the quality of controlled-load service

This paper describes a series of measurements about the characteristics of a reserved controlled-load flow in a simple router network at the presence of excessive background traffic, which was forwarded on a best-effort basis via a common link between two routers. Results concerning the delays and packet loss of the controlled-load flow are discussed and compared to those of the best-effort flow. The tests were carried out according to the simple evaluation criteria given in the RFC specifying the controlled-load service. A quite reasonable performance was measured, roughly satisfying the goals of the controlled-load service. Yet, the presence of background traffic introduced a clear increase in the average level of the network delay of the reserved flow, and also resulted in a larger jitter, which could be intolerable to inelastic traffic.