Search

P2P systems are characterised by large-scale distribution and high degree of architectural dynamics caused by their lack of central coordination. In such an environment, it is notoriously hard to guarantee a good quality of service. Simulation can help to validate network designs and protocols, but most existing simulation approaches cannot cope with unbounded dynamic change of network topology. We propose an approach to modelling and simulation of P2P systems based on graph transformations, a visual rule based formalism that has recently been supported by facilities for stochastic modelling and simulation. Focussing on P2P VoIP applications such as Skype, we model alternative solutions to the problem of selection of and connection to super nodes (i.e., the peers acting as servers in the network) and evaluate these through simulation. [ABSTRACT FROM AUTHOR]

P2P VoIP traffic potentially suffers from performance issues like packet loss, delay, jitter and echo [1], which greatly affect the quality of the service (QoS). Packet loss and delay mostly occur due to network reconfiguration caused by peer dynamics. In case of VoIP traffic, the network has to recover fast enough so that the quality of service is not affected [2]. [ABSTRACT FROM AUTHOR]