Measuring large overlay networks - the overnet example

Abstract Peer-to-peer overlay networks have grown significantly in size and sophistication over the last years. Meanwhile, distributed hash tables (DHT) provide efficient means to create global scale overlay networks on top of which various applications can be built. Although filesharing still is the most prominent example, other applications are well conceivable. In order to rationally design such applications, it is important to know (and understand) the properties of the overlay networks as seen from the respective application. This paper reports the results from a two week measurement of the entire Overnet network, the currently most widely deployed DHT-based overlay. We describe both, the design choices that made that measurement feasible and the results from the measurement itself. Besides the basic determination of network size, node availability and node distribution, we found unexpected results for the overlay latency distribution. 1 Description of Overnet and Kademli