MBRS: A Meridian-Based Relay Selection algorithm for P2P VoIP

Nowadays P2P VoIP system such as Skype has been widely used. A method to improve the QoS of P2P VoIP is to construct the application layer routing by selecting relay nodes in the P2P network. For this purpose, a distributed relay selection algorithm called MBRS which is based on Meridian is proposed. A new concept called latency routing table is put forward to replace the ring of Meridian and the members of latency routing table are selected based on AS topology information. The method of selecting a node satisfying multiple constraints in Meridian algorithm is used to select the relay node. The results of simulation show that MBRS can find relay paths whose latency are shorter than direct IP routing at more than 95% success rate when the latency range is above 150ms. Compared with a famous relay selection algorithm ASAP, the effect of QoS improvement is almost the same but the overhead of measurement is averagely reduced by 60%.