Overlay networks - A scalable alternative for P2P

Overlay networks create a structure virtual topology above the basic transport protocol level that facilitates deterministic search and guarantees convergence. Overlay networks have a network semantics layer above the basic transport protocol level that organizes the network topology according to the nodes' content, implementing a distributed hash table abstraction that provides load balancing, query forwarding, and bounded lookup times. This paper outlines the differences between flooding-style and overlay networks, and offer specific examples of how researchers are applying the latter to problems requiring high-speed, self-organizing network topologies.