单向传输系统中文件传输可靠性研究

发布时间：2018-06-28 00:14

本文选题：单向传输 + 容错性　；参考：《国防科学技术大学》2014年硕士论文

【摘要】：互联网的诞生为人类社会提供了一个快速获得实时数据信息的平台,与此同时互联网的安全性问题给接入互联网的计算机带了信息泄露的风险。为了保证高密级网络在获取互联网实时信息的同时确保信息不泄露,技术人员开发出单向传输系统作为高密级网络从低密级网络安全地获取信息的工具。因为该系统遵循严格单向无反馈的文件传输方式,文件传输可靠性难以保证。所以单向传输系统的可靠性问题已经成为限制其市场发展的瓶颈。首先,本文针对单向传输系统中的丢包问题进行研究。造成单向传输系统中文件传输可靠性问题的主要原因是传输过程中的丢包现象,传输过程中的丢包现象一般分为随机丢包与拥塞丢包两类。通过实验与分析得到结论:单向传输系统中的丢包率高低与传输速率和包负载大小有关。通过理论分析发现拥塞丢包事件之间存在马尔科夫相关性,表明在传输过程中拥塞丢包事件发生时有极大的概率伴随着连续丢包。接着,本文在基于丢包问题研究结论的基础上提出使用CRS纠删码提高单向传输的可靠性。利用纠删码进行冗余编码后传输,能够提高传输过程的可靠性。经过试验验证发现,CRS纠删码相比传统的RS纠删码在编码与重构效率有极大提高,并且在牺牲一定带宽资源的前提下能够极大提高单向文件传输容错性。最后,本文提出对CRS纠删码进行编码效率优化,经过算法分析与实验论证得出以下四个优化步骤:1.对CRS生成矩阵进行优化。2.选取适当大小的数据缓冲区与编码缓冲区。3.根据实际需求选取(n,m,w)的编码组合。4.根据编码组合计算出最优数据包大小。
[Abstract]:The birth of the Internet provides a platform for human society to obtain real-time data information quickly. At the same time, the security of the Internet brings the risk of information leakage to the computers connected to the Internet. In order to ensure that the high secret network can obtain the real-time information of the Internet and ensure that the information does not leak, technicians have developed a one-way transmission system as a tool for the high secret network to obtain the information safely from the low level network. Because the system follows strict one-way file transfer without feedback, it is difficult to guarantee the reliability of file transmission. Therefore, the reliability of one-way transmission system has become a bottleneck restricting its market development. Firstly, this paper studies the problem of packet loss in one-way transmission system. The main reason for the reliability of file transmission in unidirectional transmission system is packet loss, which is generally divided into random packet loss and congestion packet loss. Through experiment and analysis, it is concluded that the rate of packet loss in one-way transmission system is related to the transmission rate and the size of packet load. It is found that there is a Markov correlation between congestion and packet loss events through theoretical analysis, which indicates that there is a great probability that congestion packet loss events occur with continuous packet loss in the transmission process. Then, based on the research results of packet loss problem, CRS erasure codes are proposed to improve the reliability of one-way transmission. The reliability of transmission process can be improved by using erasure code after redundant coding. Experimental results show that CRS erasure codes can greatly improve the coding and reconstruction efficiency compared with the traditional RS erasure codes, and can greatly improve the fault-tolerance of unidirectional file transmission at the expense of certain bandwidth resources. Finally, the coding efficiency of CRS erasure codes is optimized. The following four optimization steps: 1: 1 are obtained through algorithm analysis and experimental demonstration. Optimize CRS generation matrix. Select the appropriate size of the data buffer and encoding buffer. 3. According to the actual requirements, select the coding combination. 4. 4. The optimal packet size is calculated according to the coding combination.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.08

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