Origins of Microcongestion in an Access Router

摘要

Using an authoritative data set from a fully instrumented router at the edge of a core network, packet delays through an access link are studied in detail. Three different root causes of delay are identified and discussed, related to: unequal link bandwidth; multiplexing across different input links; and traffic burstiness. A methodology is developed and metrics are defined to measure the relative impacts of these separate, though inter-related, factors. Conclusions are given regarding the dominant causes for our representative data set.