Communicating with low latency peers

Abstract

In decentralized applications requirements on latency are high. For instance, in trading
applications a millisecond latency advantage can save companies millions of dollars. In
this thesis a design is proposed for an overlay in a decentralized peer-to-peer system
that lowers the latency between connected peers. The overlay is designed and imple-
mented on top of Tribler, a BitTorrent client developed at Delft University of Technol-
ogy. The client continually connects toward the peers with the lowest latency to keep
an established connection towards them. Next to that, the introductions in the peer
discovery mechanism are chosen in such a way that introduced peers have a low la-
tency toward each other. To achieve this latency estimation algorithms are used that
estimate the latency between arbitrary peers in the network. These algorithms require
a limited amount of measured latencies between peers in the network and can estimate
the others. Latencies are continually measured toward peers that have an established
connection to a client. These measured latencies are shared to other peers for further
improvements on the quality of the latency estimation algorithms. The overlay design is
evaluated on the accuracy of the latency estimation algorithms, computation time and
to what extent the connections of a peer are low latency. The results show that the peers
in the overlay are able to connect toward their lowest latency peers despite low accuracy
of the latency estimation algorithms.