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Questa categoria contiene le 17 pagine indicate di seguito, su un totale di 17.
The congestion control for multimedia applications (Voice over IP, video on demand) is an open issue. We have evaluated the congestion control strategies employed by leading multimedia applications that is Skype for the VoIP application and RealNetworks for the video on demand applications. We have found out that both applications doesn't employ a valuable congestion control scheme.
We have evaluated how Helix Player behaves when available bandwidth reductions take place in order to find out how it reacts to congestion episodes. The figure below shows how the throughput of an helix connection experiencess up to 30% of packet losses when another helix flow enters the link (between ~30s and 90s).
Skype is the most popular VoIP application with over 250 million userbase spread all over the world. It is important to study how skype reacts to packet losses in order to infer if a huge amount of skype calls can result in a congestion collapse.
Towards this end we have evaluated Skype generated flows in a local testbed. We have routed the traffic of two Skype users hosted on the same machine through a virtual machine where "tc" and "netem" have been configured in order to add delays and and to control link capacity (see figure below).
