摘要

Network distance (Round Trip Time, RTT) is an important parameter for many P2P applications to optimize their performance. Network Coordinate System (NCS) is assumed as a lightweight and scalable mechanism to predict network distance between any two Internet hosts without explicit measurements. However, most NCS cannot perfectly represent triangle inequality violation (TIV) which is a common phenomenon on the Internet. To overcome this issue, we bring forward a new network positioning system called Internet delay matrix service (IDMS). IDMS is based on two-tier DHT architecture and targets Chinese Internet P2P application. IDMS directly uses two types of delay matrices -- up-to-date delay matrix (UDM) and previous delay matrices (PDM) -- for representing the network distances without explicit measurements. Extensive simulations on our collected Chinese Internet data sets show that IDMS is an accurate, efficient, scalable and practical method for Chinese Internet P2P applications.