Transcript Taming the Torrent: A Practical Approach to Reducing Cross

Taming the Torrent:
A Practical Approach to Reducing Cross-ISP
Traffic in Peer-to-Peer Systems
David R. Choffnes and Fabián E. Bustamante
Speaker: Wally Chang
Publisher: SIGCOMM 2008
Motivation
P2P traffic is massive
and random
 Transmission usually
performs better in
the same ISP
 Billing problems
between ISPs

Previous Works

ISPs guide peers for partnership
formation
◦ Biased peer selection by Bindal et al. (ICDCS
2006) , Aggarwal et al. (CCR 2007) and Xie et al.
(SIGCOMM 2008)

Remaining issues
◦ Peer adoption
◦ Legal problem
Proposed Method

Hypothesis
◦ If two peers are close to the same CDN
replica, they are close to each other
◦ Links between “nearby” hosts cross few ISPs

Measuring the relative network distance
by comparing name of the CDN replica
CDN Service
• The web site with CDN
service will store its
components in CDN
replica
 When a end user visit a
web page…
◦ Request components from
the web site
◦ The CDN DNS will tell
where to get the
components

The CDN replica and
the end user are
“nearby” (SIGCOMM 06)
Comparing the Similarity of CDN replica

Records the percentage of each CDN
replica
Server name

Percentage of connecting to this
server
Cosine similarity
Data Collection

Ono
◦ An extension to the BitTorrent

Type of data
◦ RTT (ping)
◦ IP hop (traceroute)
◦ AS hop (traceroute & AS query tool)

Figures are plotted based on a 2-week
study in December, 2007
Reducing Cross-ISP Traffic
Finding Nearby Peers
Ono in Different ISPs (1/3)
Ono in Different ISPs (2/3)
Ono in Different ISPs (3/3)
Using Different CDN Customers

Different CDN customers may have different quality
of service in CDN
Effect of Different CDN Customers
(1/2)

The more CDN replica names, the better
Effect of Different CDN Customers
(2/2)

“AB” is using Limelight CDN service, which is a
smaller CDN service company
Discussion

Overhead
◦ Requires periodically DNS lookup
 18KB up and 36KB down per day
Free-riding on CDN service providers
 Practical

◦ No extra infrastructure needed
◦ Performance improvement
Reference
Ao-Jan Su et al, “Drafting Behind Akamai
(Travelocity-Based Detouring)”, In Proc. of
ACM SIGCOMM 2006., September 2006
 Ao-Jan Su et al, ”Relative Network
Positioning via CDN Redirections”, In Proc.
of the International Conference on Distributed
Computing Systems (ICDCS), (to appear) June 2008
 David R. Choffnes and Fabián E. Bustamante,”
Taming the Torrent: A practical approach
to reducing cross-ISP traffic in P2P
systems”, In Proc. of ACM SIGCOMM 2008.,
August 2008.
