Abstract

With the ever-increasing P2P Internet traffic, recently much attention
has been paid to the topology mismatch between the P2P overlay and the
underlying network due to the large amount of cross-ISP traffic.
Mainly focusing on BitTorrent-like file sharing systems, several
recent studies have demonstrated how to efficiently bridge the overlay
and the underlying network by leveraging the existing infrastructure,
such as CDN services or developing new application-ISP interfaces,
such as P4P. However, so far the traffic locality in existing P2P li
ve streaming systems has not been well studied.


In this work, taking PPLive as an example, we examine traffic locality
in Internet P2P streaming systems. Our measurement results on both
popular and unpopular channels from various locations show that
current PPLive traffic is highly localized at the ISP level. In
particular, we find: (1) a PPLive peer mainly obtains peer lists
referred by its connected neighbors (rather than tracker servers) and
up to 90% of listed peers are from the same ISP as the requesting
peer; (2) the major portion of the streaming traffic received by a
requesting peer (up to 88% in popular channels) is served by peers in
the same ISP as the requestor; (3) the top 10% of the connected peers
provide most (about 70%) of the requested streaming data and these
top peers have smaller RTT to the requesting peer.  Our study reveals
that without using any topology information or demanding any
infrastructure support, PPLive achieves such high ISP level traffic
locality spontaneously with its decentralized, latency based, neighbor
referral peer selection strategy. These findings provide some new
insights for better understanding and optimizing the network- and
user-level performance in practical P2P live streaming systems.


Speark Bio

Yao Liu is a Ph.D. student of Computer Science Department at George Mason University.