Dynamic Operation of Peer-to-Peer Overlay Networks

Virtual overlay networks, such as virtual private networks or peer-to-peer services, can be seen as a new paradigm for providing multi-service networks. Virtual overlay networks may offer customized services to a specified community while providing a high degree of flexibility in the usage of shared resources. This paper examines the requirements of operating dynamic overlays, in particular, for peer-to-peer services. The analysis is based on extensive measurement studies performed on the global Gnutella network during operation. The obtained results indicate limitations in scalability of native p2p overlays, suggesting the need of a control scheme for efficiency reasons. As an enabling infrastructure to implement a distributed control scheme for p2p overlays a so-called ApplicationLayer Active Networking (ALAN) platform has been chosen. Based on Application-Layer Active Networking, Active Virtual Peers (AVP) are introduced as the main concept for dynamic operation and management of peer-to-peer overlay networks. AVPs facilitate policy enforcement or performance management by means of self-organization, predominantly on the application layer with minimum interference on lower layers.