RTT measurement and its dependence on the real geographical distance

In recent years, more and more network applications appear to require an accurate knowledge of the Internet station geographical positions in order to operate properly. Real geo-position could play a part in many location-based applications. A typical example is the requirement by the web server owners to be able to find out their websites visitors´ geographical position more accurately, than the national level. Thus, the underlying geolocation algorithms are being developed. Most of them use the RTT (round-trip-time) values measurement, whose results are then mapped onto geographical distances. This paper deals with the dependence of RTT on the geographic distance. All the measurements needed for dependence determination took place in a dynamically growing Planetlab network, which tries to simulate real Internet environment. The result of this work is a set of RTT values measured in real IP networks and their brief analysis.