Explain the fundamental conflict between tolerating burstine

Explain the fundamental conflict between tolerating burstiness and controlling network congestion.

Solution

-->Flow of virtual clock is running behind real time,the difference between tow may be considered some sort of
credit that the flow has built up.
-->As packet traffic is bursty ,it may seem reasonable to allow such credit savings for later use.
-->From a resource allocation viewpoint,however,unused esources are gone.
-->If a flow were allowed to save up an arbitary amount of credit,it could remain idle druing most time of its
session and then send all the data at the last second.
-->Such behaviour would violate the specified average packet rate over each AI period and may cause temprorary
congestion in the network.
-->However,it would not be detected by the virtualclock monitoring methods,since the flow would have saved adequate
credit beforehand.
-->There is, therefore,a conflict between tolerationg burstry transmissions and controlling network congestion.
-->The parameter of average interval is chosen precisely to compromise the two.
--.Data transmission of a flow can vary within each average interval,but no credit may be saved from on average interval
to the next.
-->Each switch enforces this policy by resetting the virtualclock to the real time at checking point if the former
ever lags behind.