Software Defined Underlay-aware Structured Peer-to-Peer Overlay

Abstract

Structured Peer-to-Peer (P2P) overlay networks based on Distributed Hash Table (DHT) provide self-organization and fault tolerance along with good look-up efficiency. This makes them a perfect alternative for designing distributed applications where participating entities (peers) leave or join the system dynamically. However due to continuous churn of peers, periodic maintenance of overlay structure is required resulting in large amount of network traffic. This issue becomes more critical when logical overlay topology is different from actual physical network topology which is a common phenomenon in P2P overlay networks. In this paper, we present a novel approach of designing DHT based P2P overlays using Software Defined Networks (SDN) paradigm. SDN provides flexible ways to tune the policies and rules of underlying physical network dynamically according to the application. In our approach, we have used SDN concepts to bring the overlay topology closer to actual physical topology with an aim to reduce the maintenance traffic. We have implemented an improved SDN based DHT on a smaller scale as proof of concept. The experimental results suggest and establish the applicability of our approach.