Research on the Correlation between Network Delay and Geographic Distance in Internet

The correlation between geographic distance and network delay plays an important role in network measurement. The analysis shows that the relation between distance and delay is linear. By comparing different network delay estimation methods, it is concluded that the statistical result of RTT of HTTP servers uniformly distributed in the earth should be calculated by using TCP handshake procedure. Measurement result under real condition reveals the linear relations between graphic distance and round trip delay in different areas show significant differences.