Abstract :
Packet-based communications networks began as limited tools of the research and the defence communities. Over the intervening years the scenarios have got more and more complex . . . packets are of variable length, but in practice probably conform to slightly messy, multimodal distributions rather than the simple exponential distributions that underlie much classical queue modelling; quality of service (QoS) requirements has required the use of complex, non-FIFO scheduling; power-laws have been discovered in surprising places; topology has been shown to interact strongly with traffic; increasing reliance on measurement to supplement and support prediction has led to a growing awareness that this too has its limitations.
