Information Technology Reference
In-Depth Information
An Improved Cooperative Model
of P2P and ISP
Ying Liu
1
,
3
, Shenglin Zhang
1
,
3
, and Hongying Liu
2
1
Institute for Network Sciences and Cyberspace
Tsinghua University, Beijing 100084, China
2
School of Mathematics and Systems Science
Beihang University, Beijing 100191, China
3
Tsinghua National Laboratory for Information Science and Technology
Tsinghua University, Beijing 100084, China
liuying@cernet.edu.cn, slzhangsd@gmail.com,liuhongying@buaa.edu.cn
Abstract.
P4P (Provider Portal for Applications) is a model aiming
to incorporate P2P with ISP and improve the performance of both the
ISP and the P2P applications. In this study, we analyze the relationship
between the link trac and the P-distance, which is the core interface of
P4P, and illustrate the disadvantage of P4P in dealing with network
topology with bottleneck links. Further, with
link utility function
as
the optimization objective, we propose an improved model-
Improved-
P4P
, making the trac produced by P2P applications more homoge-
neous, which can reduce the peak link utilization and protect bottleneck
links, and then improve both the network eciency and the P2P perfor-
mance. We have built a simulation platform based on BitTorrent and
conducted extensive simulations. These simulations demonstrate that
Improved-P4P
achieves a lower cost for ISPs and a better performance
for P2P applications than native P2P. Moreover, compared with P4P,
Improved-P4P
reduces trac on bottleneck links without compromising
on the performance of the P2P applications. We believe that relieving
of pressure on bottleneck links hold great significance especially in ex-
treme settings.
Improved-P4P
performs steadily in different swarm sizes,
proving that it is scalable and easy to deploy.
Keywords:
Subgradient Method, P2P, Trac Engineering, Coopera-
tive Model, Dual Function.
1 Introduction
1.1 Background
The P2P (peer-to-peer) concept has fundamental advantages over the traditional
C/S (Client/Server) model and the fixed infrastructure content distribution net-
works because of its excellent robustness and scalability, and plays an important
role in modern networks. Some researches have found that more than 50% of the
network trac is introduced by P2P [1,2], and the massive trac generated by
