Yes, We LEDBAT: Playing with the New BitTorrent Congestion Control Algorithm

Since December 2008, the official BitTorrent client is using a new congestion-control protocol for data transfer, implemented at the application layer and built over UDP at the transport-layer: this new protocol undergoes the name of LEDBAT, for Low Extra Delay Background Transport. In this paper, we study different flavors of the LEDBAT protocol, corresponding to different milestones in the BitTorrent software evolution, by means of an active testbed. Focusing on single flow scenario, we investigate emulated artificial network conditions, such as additional delay and capacity limitation. Then, in order to better grasp the potential impact of LEDBAT on the current Internet traffic, we consider a multiple flows scenario, and investigate the performance of a mixture of TCP and LEDBAT flows, so to better assess what “lower-than best effort” means in practice. Our results show that LEDBAT has already fulfilled some of its original design goals, though some issues still need to ...

• Type: Conference
• Year: 2010
• Where: PAM
• Authors: Dario Rossi, Claudio Testa, Silvio Valenti
• Keywords: BitTorrent Software Evolution, Computer Networks, Low Extra Delay, Official Bittorrent Client, PAM 2010