Applications such as Napster and Kazaa have demonstrated extensive
research potential for peer-to-peer (P2P) systems. P2P systems
inherently have high scalability, robustness and fault tolerance
because there is no centralized server and the nodes self-organize the
network on join and leave. This is achieved at the cost of increased
search time for the resources of interest. IP telephony can be viewed
as an application of P2P architecture where the participants form the
self-organizing P2P overlay network to locate and communicate with
other participants.

My talk has two parts: in the first half I will give an overview of
some of the existing structured and unstructured peer-to-peer systems
such as Napster, Kazaa and Chord. In the second half, I will talk
about how P2P can be used for IP telephony, in particular for the
Session Initiation Protocol (SIP)-based systems.