KATT Efficient publish subscribe telemetry transport in a hierarchical Kademlia topology

Abstract

Traditional Internet of things systems suffer from limitations inherent to the clientserver architecture, with the entire system being dependant on the correct functionality of the server. Alternative decentralized solutions have their own set of drawbacks, demanding more overhead and lacking the ease of configuration provided by the centralized approach. In this thesis I present KATT, a protocol for topic based, decentralized, publish/subscribe communications in a Kademlia distributed hash-table. This protocol is designed to minimize the overhead required and allow for easy network configuration, whilst maintaining the resilience and fault tolerance of a decentralized peer-to-peer system. This is achieved by the encoding of hierarchical topics within the identifiers of peers, achieving a high degree of proximity between publishers and subscribers to a specific topic in the underlying Kademlia structure. I also present KattCast, an algorithm for efficiently traversing the Kademlia structure to allow for subscriptions to wildcard topics.