摘要近些年来，Internet在全球范围内呈现快速的发展趋势，其所拥有的用户数量和网络规模都急剧的增长，越来越多的人开始使用互联网进行视频购物等服务。而与之对应是的是在实际中Internet所表现出来的网络拥塞状况日趋严峻并且越来越严重。网络拥塞会对网络造成极其负面的影响，会造成传输过程中时延增大、数据吞吐量降低等问题。在传统方式中，对于网络拥塞，Internet主要是采用TCP的端到端拥塞控制，然而在面对目前快速增长的业务量，原有的TCP拥塞控制已经不能很好的解决网络中所面临的实际需求和问题，因此在路由器中加入合适的队列管理机制和分组调度机制的拥塞控制相较于传统方法而言成为了新的选择和热门方向。33549
本文第一部分阐明网络拥塞的具体定义以及网络拥塞在实际过程中产生的根本原因。第二部分在控制理论的基础上对TCP/AQM控制策略进行分析，并且对于主动队列管理算法中的RED算法加以介绍和分析,剖析RED算法在具体网络中的表现性能，并且从控制理论的角度出发提出一种PID控制器，设计出新的AQM算法。第三部分是实验和仿真部分，使用NS2作为仿真工具，在PI算法的基础上加入D算法上构成PID主动队列管理算法，比较PID算法和RED算法在不同的指标上的性能。
毕业论文关键词  拥塞控制  队列管理  RED   PID
毕业设计说明书外文摘要
Title  Research and Implementation of Network Congestion Control Algorithms Based on PID                                                
Abstract
In recent years, Internet on the one side presents worldwide trend of rapid development. The number of users and the size of the network is sharply increasing. The number of people that watch the videos and do shopping online is increasing. However, on the other side, Internet congestion actually is more tough and getting worse. Network congestion will result in an extremely negative impact on the network ,which can cause transmission delay, increase data throughput degradation and other issues. In conventional ways, to deal with network congestion, Internet is mainly used TCP end-to-end congestion control. But in the face of rapid growth in business volume, the original TCP congestion control is not an effective way of solving real network problems. Therefore adding a suitable queue management and packet scheduling mechanisms for congestion control in the router becomes the new choice of different researches and gets popular compared to traditional methods.
The first part of this essay is clarifying the specific definition of network congestion. On the basis of control theory, the second part analyze the TCP / AQM controlled strategy, in which active queue management algorithm— RED algorithm is introduced and analyzed, PID controller then is proposed on the basis of RED algorithm and PID active queue management algorithms. The third part is the part of the experiments and simulations using a simulation tool NS2, which is added PID AQM to extend its functionality based on PI algorithm after adding D algorithm. After that we compare the PID algorithm and RED algorithm performance on different indicators.
Keywords  congestion control  AQM  RED   PID
 目   次
1  绪论1
2  网络拥塞控制机制 5
2.1  TCP拥塞控制机制 6
2.2  TCP拥塞控制存在的问题 6
2.3  IP拥塞控制机制9
3  主动队列管理算法9
3.1  控制理论下的TCP/AQM拥塞制9
3.2  RED算法10
3.3  PID算法14 PID网络拥塞控制算法的研究和实现:http://www.youerw.com/tongxin/lunwen_30712.html