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Summary: The Impact of False Sharing on Shared Congestion
Management
Aditya Akella y Srinivasan Seshan y
1 Introduction
Recently, several proposals have been made for sharing congestion
information across concurrent flows between endsystems. In these
proposals, the granularity for sharing has ranged from all flows to
a common host to all hosts on a shared LAN. While these propos
als have been successful at ensuring sound AIMD behavior of the
aggregate of flows, they suffer from what we term ``false sharing''.
False sharing occurs when two or more flows sharing congestion
state may, in fact, not share the same bottleneck.
In this work, we investigate the effects of false sharing on shared
congestion management schemes. We characterize the origins of
false sharing into two distinct cases: (i) networks with QoS en
hancements such as differentiated services, where a flow classi
fier segregates flows into different queues, and (ii) networks with
path diversity where different flows to the same destination address
are routed differently -- a situation that occurs in dispersity rout
ing, loadbalancing, and with network address translators (NATs).
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