Back Ground Traffic Aware-Based Research And Implementation For Traceroute

Link reliability in large networks is very important, which impacts network availability directly. Link failure will not only reduce the network performance, but also interrupt the network connection. Some investigations indicate that, as link failures happen every day, so it is particularly important to improve the performance of network to monitor the occurrence of link failures and the distribution law of link failures. But the existing methods of measurement, including active measurement and passive measurement, could not satisfy the need of failure measurement.The main work and contribution of the paper is as follows:First, we present Traceroute-based failure detection algorithm with background traffic (BTAFD). The detection algorithm uses a combination of both active and passive measurement. When there is not background traffic in the network, we will choose to send probe packets periodically to detect the failure. However, when there is background traffic in the network, we will prefer to use the background traffic instead of probe packets to detect the failure.Second, we have implemented the algorithm and made some emulation about the algorithm in NS2, and also introduced the traffic matrix of GEANT and Abilene to check and analyze the performance of the algorithm, including failure detection delay, failure recovery detection delay and the number of probing packets. The results show that the overhead of probe packet in our method has been significantly reduced when there is background traffic in the network. Finally, the simplified version of algorithm actually is deployed on the CERNET2 network to measure the 25 core nodes of CERNET2 and the links between them. We obtain the characteristics of link failures happened in CERNET2 backbone by analyzing the collecting data, including the distribution of link failure, the duration of the failure,and the internal between failure. The results show that link failures on the CERNET2 backbone happen rarely, and that the average duration of link failures is short, therefore, CERNET2 is a reliable network.