Packet Loss Rate Tomography And Hybrid Active Network

With the rapid development of the computer network, the traditional centralized network measurement system is challenged by the measure to multi-vendor and multi-technology heterogeneous network and exposes some deficiencies. At the same time, people want to decrease the extra load taken by the measurement. Network tomography is a new method of network measurement. It doesn't need the corporation of the interior nodes, and will complete the task only by collecting message from the edge. This method doesn't has high demand on hard equipments. With these characteristics, Network tomography is called the new measurement in current network. It's a new technology for inferring the link parameters, network topology and OD(Origin-Destination)flows. It has solved the problem in traditional network measurement that needed the cooperation of the interior nodes and hard to run in heterogeneous network. In this thesis, It makes an in-depth research on the related technology of inferring the link losses in unicast network.The current methods of inferring link losses in unicast tomography need to send multiple probe packets. Whereas, the large numbers of probe packages is not acceptable for some network environment, especially in wireless sensor network. We will propose our ideas about the problem described above, and give some new algorithms based our ideas.Firstly, aims at the characteristics and weakness of the stripes of packets(with no delay between transmission of successive packets within a stripe), we introduces a new link-level loss estimate method called multi-packet stripe. This new measurement can decline the number of probe packets at the basic of insuring the accuracy.Secondly, based on the two-leaf tree mode, we proposed the three-leaf tree mode. This new mode can build more equations the two-leaf tree. We can observe good estimate accuracy with it. In other words, we can decrease the probe packets and get accurate link-level loss estimates.Both the multi-stripe packet and three-leaf tree mode can get fruitful inference of...