Latency/Bandwidth Tradeoff in Gigabit Networks

Leonard Kleinrock, UCLA; in IEEE Comm. April 1992

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Content Summary

Because of the speed-of-light limitation, gigabit networks have a behavior that is qualitatively as well as quantitatively different from that of slower networks. Queueing theory is used to derive the "critical curve" for channel capacity delineating operating regions in which a network is bandwidth-limited from regions in which it is latency-limited, given a particular network load. Also, because of the large capacity of long-haul gigabit networks, congestion control is not enough; end-to-end flow control must be used to control the backup of bits in the pipe. The paper also claims that statistical effects can be used to handle a large number of bursty sources in order to improve overall efficiency, but a recent paper On the Self-Similarity of Ethernet Traffic suggests that this conclusion may be based on an assumption that is not borne out by measurement of traffic patterns.

Relevance to Multimedia

Multimedia relies on high-bandwidth networks and can benefit from gigabit capacities, but until recently low latency has been taken for granted. The real-time nature of many multimedia applications, especially collaborative apps, requires us to reexamine our operating assumptions.

Rating

3 out of 5: sort of an obvious issue, but a good exposition.
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