Reliability and relay selection in peer-to-peer communication systems
Salman Baset, Henning G. Schulzrinne · Principles, Systems and Applications of IP Telecommunications · 2010
The presence of restrictive network address translators (NATs) and firewalls prevent nodes from directly exchanging packets and thereby pose a problem for peer-to-peer (p2p) communication systems. Skype, a popular p2p VoIP application, addresses this problem by using another Skype client (relay) with unrestricted connectivity to relay the signaling and media traffic between session endpoints. This distributed technique for addressing connectivity issues raises challenging questions about the reliability and latency of relayed calls, relay selection techniques, and the interference of relayed calls with the applications running on relays -- a phenomena we refer to as user annoyance.