Abstract: NS2 is widely used to research the computer network based on discrete event simulation technique.But the traditional link model of the NS2 is complex and can hardly satisfy the requirement of the large-scale network simulation.To reduce the computation cost of network simulation，and consequently to increase the scale and the performance of network simulation，this paper presents a new link model for NS2.In this link，it no longer maintains a real packet-queue and some of the discrete events are replaced by direct computing in order to reduce the number of discrete events and the simulation time.Experiments show that compared with the traditional discrete event network simulation，the simulation time can decrease over 35%，and meanwhile ensure the accuracy of the results.

Key words: discrete event simulation, network simulation, simplified link model

摘要： 基于离散事件模拟技术的NS2网络模拟器被广泛运用于计算机网络的研究中。传统的NS2链路模型复杂度高，导致了大规模网络模拟由于需要大量的计算时间而难以实现。为降低网络模拟所需要的计算开销，以提高网络模拟的规模以及性能，提出一种简化的NS2链路模型。与传统的NS2链路模型相比，该模型在不影响网络模拟真实性的前提下，不再在链路模型中维护分组缓存队列，并将部分离散事件采用直接计算来处理，以减少离散事件个数，降低模拟运行时间。实验表明，该模型在保证真实性的前提下，使模拟运行时间减少35%以上。

关键词: 离散事件模拟, 网络模拟, 简化链路模型