基于PLE的有确定解的端到端网络链路时延推测方法

网络时延是重要的网络性能指标，端到端网络时延推测能够克服传统的基于路由器或者路由器协作的网络测量技术的弊端。在网络拓扑已知且稳定和链路性能时空独立性的假设前提下，给出了网络链路时延推测模型，提出了一种基于伪似然估计(PLE)的有确定解的端到端网络链路时延推测方法。在应用期望最大化算法的伪似然估计的基础上，控制背靠背发包方式，确定可以求解的探测单元，解决了不满足有确定解拓扑下的求解问题，且有效降低了计算复杂度。最后利用基于模型的计算验证了该方法的准确性和有效性。

Research on Approach to End-to-end Network Link Delay Inference Based on PLE with Definite Solution

Network delay is one of the important network performance parameters. End-to-end network delay inference could deal with the difficulties caused by other network measurements based on internal routers or muter cooperation.Under the condition of two assumptions, network topology structure is gotten and stable, link performance is temporally and spatially independent, network delay inference model was presented, a new approach to network internal link delay inference based on Pseudo Likelihood Estimation(PLE) with definite solution was proposed in this paper. Based on PLEsolved with Expectation Maximum(EM) algorithm, inference units with definite solution were determined via back-to-back packet sending way. This approach could solve the problem of indefinite solution and lower the computation complexity. Experimental study was performed based on model computation. The experimental results show that the approach is accurate and effective.