网络混合仿真及其在NS-2下的实现

Hybrid Network Simulation and Its implementation in NS-2

将流仿真与数据包仿真结合的混合仿真可以同时利用两种仿真技术的优势。该文在V ishalM isra的流模型的基础上提出了混合仿真模型的实现框架。在仿真模型基础上,基于数据包仿真工具NS-2实现了混合仿真。在混合模型仿真实现中,对需要包级网络性能参数的子网采用包仿真技术,其余部分采用流仿真,在得到具体包级信息的同时,大大改善了仿真效率。混合模型实现的关键在于解决包仿真和流仿真间的接口问题,文中给出了解决接口问题的具体方法。该文设计了一组试验对该混合模型进行验证,仿真结果表明模型既可以准确捕获TCP流的动态特性,又可以提高整个网络的仿真效率。

Hybrid simulation model which combines the fluid model with packet - level simulation can integrate the advantages of the two methods, This paper proposes the frame of hybrid model based on the fluid model proposed by Vishal Misra , and proposes implementation of hybrid model within Ns - 2 in detail. When using the hybrid model, we adopt packet - level simulation for the subnet which needs detailed packet - level information, and adopt fluid simulation for the others, therefore we can speedup the simulation while still knowing detailed information we need. The key of the model is how to implement the interface between packet - level model and fluid model, we show it particularly in this paper. This paper designs a set of experiments to evaluate the performance of our hybrid model. The results show that the hybrid model not only can accurately obtain the transient behavior of TCP flow, but also can shorten the simulation time.