OpenTD: Open Traffic Differentiation in a Post-Neutral World

In the absence of network neutrality, consumers are vulnerable to arbitrary traffic discrimination policies applied by Internet Service Providers (ISPs). In this paper we propose a framework that gives ISPs flexibility to practice differentiation, while being open so consumers can make informed choices, and accountable so regulators can oversee adherence. We begin by outlining the SDN-based architecture of our solution, comprising the segregation of traffic into a chosen number of classes, and dynamic partitioning of bandwidth amongst classes based on utility functions. We then highlight the flexibility of our framework in accommodating a wide range of behaviors, from fully-neutral to per-application-type and per-subscriber-tier differentiation. We evaluate our scheme via simulations of real traffic mixes to show how ISP differentiation policies can be tuned to meet a range of user needs, and implement our scheme in a testbed network to demonstrate practical feasibility. We believe our proposal is a promising approach to keeping ISPs, consumers, and regulators happy in a post-neutral world.