单向链路下高可靠数据传输方法研究

发布时间：2018-08-20 08:52

【摘要】：为了彻底杜绝涉密网络中信息的泄露,无反馈的单向链路通信成为当前网络安全领域比较可行的物理隔离技术方案。然而,由于单向链路只有单向传输的能力,在这种环境下无法通过应答方式来确保数据传输的可靠性。为了满足高安全度网络的通讯需求,单向传输的可靠性问题成为单向隔离技术中需要解决的关键问题。本文利用网络通用部件设计基于分光还原技术的单向通信链路,并结合ErasureCode、PF_RING、单向通信等关键技术,在分析udp协议的基础上设计系统协议,并基于不同的发传输速率设计不同的单向控制策略。经过不断的测试,最终实现单向导入、高速传输、安全隔离、可靠传输的预期目标。具体的研究工作如下:1、研究单向链路下数据传输速率和丢包率之间的相关性。随着传输速率的变化,丢包率也发生明显的变化。基于这种相关性,本课题研究将提出两种不同的单向控制策略。2、单向传输在链路带宽范围内,由于器件或线路等因素仍存在一定比例的丢包,这种丢包是随机的且彼此之间并无相关性。针对这种情况本文提出了一种基于最大速率的自适应编码方案,即在低丢包率下采用基于ErasureCode算法的单向控制机制,并基于最大速率估计来调整编码策略,在传输报文间建立冗余校验,将丢失的数据包冗余恢复出来。3、随着传输速率的增加,丢包率快速增加,开始出现拥塞丢包,只采用纠删编码提高容错性并不能达到理想的效果,为了抵抗纠删编码对连续丢包现象恢复性能差的弊端,本文采用在纠删编码的基础上进行传输组之间的交织编码,即将出现的连续丢包离散的分布到不同的编码包组上,进一步提高纠删码的容错性能。4、在实际链路丢包环境和Gilbert网络丢包模型下,对上述两种单向控制策略进行测试,测试结果表明:该单向控制策略能够在不同速率的单向链路环境下进一步有效地降低丢包率,较好地提高单向传输的容错性,实现单向链路下数据传输的高可靠性。本文基于单向链路通信中丢包率与传输带宽之间的关系,提出了基于速率的单向冗余控制策略,该策略对如何保证单向链路通信的高可靠性提供了一种解决思路和方案,具有重要的理论意义和研究价值。
[Abstract]:In order to completely eliminate the leakage of information in secret networks, one-way link communication without feedback has become a feasible physical isolation technology in the field of network security. However, because unidirectional links have only one-way transmission capability, the reliability of data transmission can not be ensured by answering mode in this environment. In order to meet the communication requirements of high security network, the reliability of one-way transmission has become a key problem to be solved in one-way isolation technology. In this paper, the unidirectional communication link is designed by using the general components of the network, and the system protocol is designed on the basis of analyzing the udp protocol, combining with the key technologies such as Erasure Code, PFRINGand one-way communication, etc. Different one-way control strategies are designed based on different transmission rates. After continuous testing, the final goal of one-way import, high-speed transmission, security isolation, reliable transmission is achieved. The specific research work is as follows: 1. The correlation between data transmission rate and packet loss rate in unidirectional link is studied. With the change of transmission rate, packet loss rate also changes obviously. Based on this correlation, this paper proposes two different one-way control strategies. The one-way transmission is within the bandwidth range of the link. Due to the device or circuit and other factors there is still a certain proportion of packet loss. The packet loss is random and has no correlation with each other. In this paper, an adaptive coding scheme based on maximum rate is proposed, which adopts unidirectional control mechanism based on ErasureCode algorithm at low packet loss rate, and adjusts the coding strategy based on maximum rate estimation. The redundancy check is established between the transmission packets, and the redundant data packet is restored to .3. with the increase of the transmission rate, the packet loss rate increases rapidly, and congestion packet loss begins to appear. Only using erasure coding to improve the fault-tolerance can not achieve the ideal effect. In order to resist the bad recovery performance of erasure coding to the phenomenon of continuous packet loss, the interleaved coding between transmission groups based on erasure coding is adopted in this paper, and the discrete distribution of continuous packet loss will be distributed to different groups of packets. Furthermore, the fault-tolerant performance of erasure codes is improved. The two one-way control strategies mentioned above are tested under the actual link packet loss environment and the Gilbert network packet loss model. The test results show that the one-way control strategy can further reduce packet loss rate in unidirectional link environment with different rates, improve the fault-tolerance of one-way transmission, and achieve high reliability of data transmission in unidirectional link. Based on the relationship between packet loss rate and transmission bandwidth in unidirectional link communication, this paper proposes a rate-based one-way redundancy control strategy, which provides a solution to how to ensure the high reliability of one-way link communication. It has important theoretical significance and research value.
【学位授予单位】：北京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP393.08

【相似文献】