Passive estimation of round-trip time in backbone network
骨干网络中的被动模式RTT测量方法*

To meet the network management requirements, this paper defined half-path round-trip time(HPRTT) as the RTT metric from a host to passive measurement point, and proposed a general passive method for continually measuring of HPRTT for different hosts in backbone network, also introduced a self-adaptive filter model to judge the validity of measurement samples. Comparing with current passive RTT estimation methods, this method could obtain more measurement samples from different TCP activity models thus observably improve the measurement success rate. Practical experiments are taken in Gbps backbone and HPRTTs are estimated for large numbers of TCP hosts, the result shows this method works properly and effectively.