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<DIV><FONT face=Arial size=2>I know that the topic that I will touch in the next
few lines is more close related to the PILC list, but the end2end list
(traditionally) has a more wider scope. There is a lot of research effort to
characterize the TCP performance in the last wireless hop ( a lot of
solutions[which some of them break the end-to-end principle]) but it seems that
there is a lack of more realistic performance evaluation where both the Internet
and wireless dynamics are taken into account. Mobile hosts which are connected
to a Web server which is let's say 20-25 hops away will experience both
kind of dynamics. So, it seems to me that we can characterize the profile of
this delay by a convolution of the delays in the Internet and those due to the
fluctuations on the wireless link (even though there is no such global pdf that
express the delays on the Internet,[i.e NLANR active measurements].But, I'm not
aware of pdf's of the delays on the last hop for different access schemes(
pdf that take into account the specific MAC used,ARQ,
transmission,coding-decoding).Also,concerning TCP issues, a knowledge
of possible outliers, the frequency of these outliers together with the
dynamics of the delays on the Internet would give a better (I think)
understanding of TCP{flavours} performance. If there is a work that
combines these two "worlds" I would like to be aware of. Thanks in
advance.</FONT></DIV>
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<DIV>Vasilis</DIV>
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