ASAP: an AS-Aware Peer-Relay Protocol for High Quality VoIP

Peer-to-peer (P2P) technology has been successfully applied in Internet telephony or Voice over Internet Protocol (VoIP), such as the Skype system, where P2P is used for both searching clients and relaying voice packets. Selecting one or multiple suitable peers to relay voice packets is a critical factor for the quality, scalability and cost of a VoIP system. In this paper, we first present two sets of intensive Internet measurement results to confirm the benefits gained by peer relays in VoIP, and to investigate the performance of the Skype system. We obtain the following results: (1) many relay peer selections are suboptimal; (2) the waiting time to select a relay node can be quite long; and (3) there are a large number of unnecessary probes, resulting in heavy network traffic to limit scalability of the VoIP system. Our further analysis shows that two main reasons cause these problems. First, the peer selections do not take Autonomous System (AS) topology into consideration, an...

• Type: Conference
• Year: 2006
• Where: ICDCS
• Authors: Shansi Ren, Lei Guo, Xiaodong Zhang
• Keywords: Distributed And Parallel Computing, ICDCS 2006, Skype System, Voice Packets, VoIP Systems