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.
Armando Fox ([email protected])