改进NS2对局域网分布式系统在线仿真的实现  

Implementation of Online Emulation for Distributed System in Local-area Network by Improving NS2

作　　者：李映川[1] 童晓阳[2] 丁力[3] 

机构地区：[1]江西省电力设计院,江西南昌330006 [2]西南交通大学电气工程学院,四川成都610031 [3]浙江省宁波电业局,浙江宁波315010

出　　处：《计算机仿真》2009年第9期227-231,共5页Computer Simulation

基　　金：江西省电网科技项目(200750502)

摘　　要：目前大多数仿真系统采用流量发生器等模拟l离散事件的发生,为了充分模拟网络环境中分布式系统各子系统的并发运行和彼此之间依据算法的实时交互,设有虚拟局域网VLAN的IEEE802.1Q协议。提出一种改进NS2模拟局域网分布式系统实际运行的在线仿真的集成方法,将各分布式应用对象移植为NS2的C++扩展对象,执行实际算法,构造一个模拟中心调度对象,管理各分布式对象的并发运行、转发各分布式对象之间的消息交给NS2以模拟其网络延迟,与领域仿真软件交换数据等。对NS2中共享式以太网协议模块改造,添加VLAN802.1Q协议模块,分别实现对交换式局域网和多播报文的模拟。变电站自动化系统的通信网络仿真实验结果,验证了在线仿真方法是有效的、所扩展的NS2模块是正确的。Traditional NS2 generates the event with traffic generator, which can＇ t well simulate actual parallel running and interactions of the distributed system in the network environment. In order to solve the problem, an integrated method of online - emulation is proposed for the distributed system in the local area network to simulate its real running procedure and delay of network. The distributed objects are migrated to NS2 as extended C ＋ ＋ objects to execute the algorithms. A simulation centre scheduling object is constructed to manage the parallel running of application objects, forward the messages among them to NS2 to simulate the network delay, and the data exchange with the professional simulating software. The simulation for switched Ethernet is implemented in NS2, as well as the protocol IEEE 802.1Q of VLAN to simulate the transmitting of muhicast packet. The experimental results can illustrate the validity of the simulation method and the correctness of the extended modules in NS2.

关 键 词：分布式系统 在线仿真 通信模拟 局域网 虚拟局域网 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]