An Extension of HAVE Message in BitTorrent Systems

In BitTorrent systems, there are eleven types of messages for data communication between the peers, among which HAVE, REQUEST and PIECE messages are the three main transmission parts in terms of quantity and flow. In order to improve the efficiency of network transmission and decrease the management costs of file delivery, this paper investigates the mechanism of HAVE message of BitTorrent systems and propose a novel MultiHave message scheme. Experimental results show that under the environment of high bandwidth and consistent peers, together with assistant of the timer, the flow ratio of MultiHave message to HAVE message can be reduced to 11%, so MultiHave message can decrease the flow of messages and prevent the HAVE message storm efficiently. Furthermore, MultiHave message can adapt itself to various BT systems with various bandwidths. If the action of network peers is inconsistent, it can degenerate to the original HAVE message and keep the high performance of BitTorrent systems.