Experimental Assessment of BitTorrent Completion Time in Heterogeneous TCP/uTP swarms

TL;DR

This paper experimentally evaluates how the uTP protocol affects BitTorrent completion times, revealing that mixed TCP/uTP swarms can optimize download speeds and improve user experience.

Contribution

It provides the first detailed experimental analysis of uTP's impact on torrent completion times in heterogeneous TCP/uTP environments.

Findings

All-uTP swarms have shorter completion times than all-TCP swarms.

Mixed TCP/uTP traffic can further reduce torrent download times.

uTP's design effectively minimizes interference with other user traffic.

Abstract

BitTorrent, one of the most widespread used P2P application for file-sharing, recently got rid of TCP by introducing an application-level congestion control protocol named uTP. The aim of this new protocol is to efficiently use the available link capacity, while minimizing its interference with the rest of user traffic (e.g., Web, VoIP and gaming) sharing the same access bottleneck. In this paper we perform an experimental study of the impact of uTP on the torrent completion time, the metric that better captures the user experience. We run BitTorrent applications in a flash crowd scenario over a dedicated cluster platform, under both homogeneous and heterogeneous swarm population. Experiments show that an all-uTP swarms have shorter torrent download time with respect to all-TCP swarms. Interestingly, at the same time, we observe that even shorter completion times can be achieved under careful mixtures of TCP and uTP traffic.