针对大量数据片段冗余传输造成网络传输效率降低的问题,在协议无关冗余消除技术的基础上,提出了一种基于分组特性的冗余流量消除(PFRTE)算法.该算法以对数据包大小分组为基础,动态统计和分析网络流量的双峰特性和分组特性,以对冗余消除贡献大的数据包为阈值,利用滑动窗口计算数据块的边界点,对两个边界点间的数据块计算其指纹并进行指纹匹配.对重复传输的数据块进行简单编码,用编码数据替换重复传输的数据片段,再对消除冗余流量的数据包进行传输.与基于最大值选择和基于静态查找表选择等冗余流量消除算法相比,PFRTE算法动态统计网络流量分组特性,能够大大减少服务器端和客户端的CPU运行时间,同时冗余消除字节节省了8%~40%,证明了该算法的有效性.
Concerning the low efficiency of network transmission caused by redundant traffic, an algorithm named Packet Feature based Redundancy Traffic Elimination (PFRTE) was proposed based on the protocol-independent traffic redundancy elimination technique. Based on the grouping of packet size, PFRTE dynamically analyzed statistical bimodal characteristics and packet features of network traffic and regarded the size of the packet with the greatest capability of redundancy elimination as the threshold. It decided the boundary points by using sliding window method and calculated the fingerprint of block data within two boundary points. PFRTE encoded the redundant blocks in a simple way and transfered the encoded data instead of redundant data. The experimental results show that, compared with redundant traffic elimination algorithm based on maximum selection and static lookup table selection, PFRTE has the advantage of analyzing the redundancy statistics of network traffic dynamically, and the CPU consumption reduces both at server and client. Meanwhile, the algorithm is also effective with rate of redundancy elimination bytes saving of 8% -40%.