"TopBT: a topology-aware and infrastructure-independent BitTorrent client"

Shansi Ren, Enhua Tan, Tian Luo, Songqing Chen, Lei Guo, and Xiaodong Zhang

Proceedings of INFOCOM'10, San Diego, California, March 15-19, 2010.


BitTorrent (BT) has carried out a significant and continuously
increasing portion of Internet traffic. While several designs have been
recently proposed and implemented to improve the resource utilization
by bridging the application layer (overlay) and the network layer
(underlay), these designs are largely dependent on Internet
infrastructures, such as ISPs and CDNs. In addition, they also demand
large-scale deployments of their systems to work effectively.
Consequently, they require  multiefforts far beyond individual users¢
ability to be widely used in the Internet.

In this paper, aiming at building an infrastructure-independent
user-level facility, we present our design, implementation, and
evaluation of a topology-aware BT system, called TopBT, to
significantly improve the overall Internet resource utilization without
degrading user downloading performance. The unique feature of TopBT
client lies in that a TopBT client actively discovers network
proximities (to connected peers), and uses both proximities and
transmission rates to maintain fast downloading while reducing the
transmitting distance of the BT traffic and thus the Internet traffic.
As a result, a TopBT client neither requires feeds from major Internet
infrastructures, such as ISPs or CDNs, nor requires large-scale
deployment of other TopBT clients on the Internet to work effectively.
We have implemented TopBT based on widely used open-source BT client
code base, and made the software publicly available. By deploying TopBT
and other BitTorrent clients on hundreds of Internet hosts, we show
that on average TopBT can reduce about 25% download traffic while
achieving a 15% faster download speed compared to several prevalent BT
clients. TopBT has been widely used in the Internet by many users all
over the world.

TopBT is open source software.