Can P2P Networks be Super-Scalable?

TL;DR

This paper introduces a new P2P network model that accounts for network bottlenecks and demonstrates conditions under which increasing load can decrease download times, a phenomenon called super-scalability.

Contribution

It presents a novel rate-based model for P2P networks that captures degree and locality constraints and analytically shows super-scalability conditions.

Findings

Average download time decreases with load in certain settings

Closed-form expression for download performance in the fluid limit

Super-scalability phenomenon identified and characterized

Abstract

We propose a new model for peer-to-peer networking which takes the network bottlenecks into account beyond the access. This model can cope with key features of P2P networking like degree or locality constraints together with the fact that distant peers often have a smaller rate than nearby peers. Using a network model based on rate functions, we give a closed form expression of peers download performance in the system's fluid limit, as well as approximations for the other cases. Our results show the existence of realistic settings for which the average download time is a decreasing function of the load, a phenomenon that we call super-scalability.