【作者】 解永良；

【导师】 王行刚；

【作者基本信息】 中国科学院研究生院（计算技术研究所） ， 计算机系统结构， 2003， 博士

【摘要】 网络仿真是网络系统设计的重要方法。由于现有的一些网络仿真软件不能满足网络系统设计的要求,因此我们设计、开发了一种新的面向网络系统设计的网络设计仿真器NDS-2并开展了相关的研究工作。本文针对系统仿真技术、网络仿真技术、信息网络系统设计与性能评价方法、高性能交换结构及其调度算法等方面进行了重点研究,并开展了网络设计仿真器NDS-1、NDS-2的系统设计与实现工作。现将工作总结如下:1.研究了系统仿真技术、离散系统仿真、网络仿真技术的基本过程、实现方法、具体应用,并着重对网络仿真的基本方法、存在问题及现有的网络仿真软件进行比较详细地研究,指出现有网络仿真软件不能适应网络系统设计的需要,确立了本课题的研究依据。对网络仿真软件NS-2进行了详细地分析与研究,为网络设计仿真器NDS-1、NDS-2的设计与实现打下了很好的基础。2.讨论了信息网络系统设计与性能评价的基本内容、研究方法,并对几种主要的研究方法进行了分析与比较,指出不同方法的特点以及网络仿真技术在辅助网络系统设计和性能评价方面所具有的优势。3.研究了高性能交换结构中输入排队、输出排队、组合输入输出排队的实现方法。并着重对输入排队及组合输入输出排队调度算法的吞吐量、稳定性、公平性、延迟控制、组播支持等方面进行了研究。4.在NDS-1的设计与实现工作中,提出建立一个开放式的、模块化的、面向对象的、可视化交互的一体化网络建模与仿真平台,为网络研究和设计人员提供一个直观的、灵活的、易操作的网络图形化建模与仿真数据分析界面。完成了NDS-1的系统设计并实现了可视化编辑器、仿真脚本生成器、网络仿真核心选择、仿真数据分析器,并给出了应用NDS-1进行多媒体网络性能评价的系统实例。5.在NDS-2的设计与实现工作中,提出了面向网络系统设计的网络设计仿真器应包括网络协议仿真、网络设备仿真、网络应用仿真。协议仿真主要是协议建模与仿真;设备仿真主要是通过仿真反映设备不同的体系结构和性能指标;应用仿真主要是仿真不同应用的统计特性。NDS-2具有如下特点:TCP/IP协议仿真基于真实的TCP/IP协议栈、物理网络仿真基于网络协议模型、设备仿真基于网络设备模型、应用仿真基于网络应用的统计特性模型、采用事件驱动方式来进行网络仿真、采用脚本语言和面向对象语言相结合。完成了NDS-2的系统设计并实现了绝大部分功能模块和功能,包括:FTP、Telnet、Http、TCP、UDP、IP、PPP、Ethernet、DDN、SDH、IP Router、Ethernet Switch、Ethernet Hub、Host、Pareto、Exponential、Const Bit Rate。更多还原

【Abstract】 Network Simulation is a important method of network system design.Because some existing network simulation software can’t be satisfied for requirement of network system design, I have designed and implementated a new kind of network design simulator NDS-2 oriented for network system design, and I have done many relative research concurrently. In this paper, I will mainly discuss about system simulation technology, information network system design, high performance switching architecture and its scheduling algorithm. And we have designed and implemented for NDS-1, NDS-2. Firstly, we will summerize all the work listed as below:1. I have studied about the basic procedure, implementation method, main applycation of system simulation technology, discrete event simulation, and network simulation. And I focus on the basic method and exsting problems of network simulation and exsting network simulation software. I suppose that the exsting network simulation software can’t afford to the requirement of network system design. So it is necessary for this task. I have analysis and study the network simulation software NS-2, It will be the good foundation for the design and implementation of network design simulation NDS-1, NDS-2.2. I have discussed the basic content and main methodsof information network system design and performance evaluation. And I analysis and compare these main methods. I point out that differrent method has own specialties and network simulation is predominant for aidding network system design and performance evaluation.3. I have studied the implementation of input-queued, output-queued, combined input-output queued of high performance switching arichecture, mainly focused on these aspects, such as throughout, stability, fairness, delay control, multicast support.4. In the design and implementation of NDS-1, I bring forward a open, modular, object oriented, visual interactive integrated network modeling and simulation platform, which can provide a directed, flexible and easy to operate network graphic modeling and simulation data analyse interface for network research. I have finished the system design and implemented the visual editor, simulation scripts generator, network simulation core selection, simulation data analyse. A system instance applying NDS-1 to evaluate the performance multimedia network is given.5. In the design and implementation of NDS-2,I bring forward that network design simulator should include network protocols simulation, network devices simulation, and network application simulation. Network protocols simulation refers the protocols modeling and simulation. Network devices simulation refers that differences of devices’archicture and performance parameter should be reflected. Network applications simulation refers更多还原