An Improved Network Topology Identification Method with Variable TTL

Traditional network identification methods require cooperation of all nodes, thus they cannot identify the topology of the networks where some non-cooperative nodes exist. Although the tomography based network topology identification methods require no collaboration of intermediate nodes, they suffer from high algorithmic complexity and heavy network payload. In this paper we propose a novel tomography method, which exploits a variable TTL "Sandwich" packet for topology identification. This method can reduce the amount of probe packets when identifying topology with tomography method. In addition, we propose a topology identification method based on traceroute tomography. This method constructs an incomplete initial tree according to the information gathered from traceroute, then use the tomography method to further identify the incomplete topology. This method can not only reduce the calculation complexity of topology identification based on network tomography technology, but also further reduce the required amount of probe packets. At last, the performance of the proposed method is validated by NS-2 simulations.