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<DIV id=idOWAReplyText35843 dir=ltr><FONT face=Tahoma size=2>Jing,<BR></FONT>>in ISP networks, QoS differentiation shows up only<BR>>when congestion happens; DiffServ tries to solve<BR>>bandwidth competition under congestion situation, ISP<BR>>want to differentiate e2e QoS even when bandwidth is<BR>>overprovisioned! </DIV>
<DIV dir=ltr>This is not true. There are non-work-conserving and work-conserving QoS schemes that does not depend on congestion. DiffServ does not only try to solve BW competition under congestion situations i.e. EF PHB-related services. Bandwidth is not the only limited resource in the network and is not the only means of service related parameter. </DIV>
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<DIV dir=ltr>Current applications on the Internet are congestion-sensitive. I guess that's why overprovisioning seems enough for now. </DIV>
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<DIV dir=ltr>Alper K. Demir<BR><BR></DIV></BODY></HTML>