Evaluating P2PSIP under Attack: An Emulative Study

Recently, establishing a VoIP call using a P2P network instead of regular SIP-servers has been proposed; this novel approach to SIP-signaling is commonly referred to as P2PSIP and technically based on a Distributed Hash Table (DHT). P2P networks are advantageous with respect to reliability and scalability. However, securing DHTs against adversary nodes which intentionally interrupt functionality of the network remains a major research problem. In particular, even if a trusted enrollment server is used for secure identifier assignment of participating nodes, attacks on overlay routing by malicious nodes that have successfully joined the network can still severely degrade the lookup service of the DHT. To gain insight into the ability of callers to reach callees during such attacks on DHT-routing, we present the first P2PSIP implementation that enables to emulate adversary nodes as well as the injection of a large amount of lookup requests (i.e., SIP- Invite requests) in an automated way. Further, we implemented several secure DHT routing algorithms and investigated their effect on the success rate of lookups and the maximum call-setup time in an infiltrated P2PSIP network. In general, our system provides the ability to analyze attacker behavior as well as future novel security techniques in an actual P2PSIP environment with comparably low effort.