摘要
传统TCP根据ACK的数量对网络拥塞状况进行估测,采用滑动窗口机制对发送窗口的大小进行调节,从而实现拥塞控制。但在MANET中,无论是拥塞判断方法,还是拥塞解决方法,传统TCP的表现均不尽人意。近年来提出各种对传统TCP拥塞控制的改进方法,其中Semi-TCP采用跨层设计的思想,根据节点内数据链路层缓存占用率对拥塞状况做精确检测,使网络性能大幅提升。二者采用不同的拥塞检测标准,当一条通信链路中同时存在两种协议且发生拥塞时,使用不同的拥塞检测标准势必会对后续的拥塞处理造成不良影响。研究TCP和Semi-TCP协议共存时出现的问题,并在不改变传统TCP协议的情况下,在Semi-TCP协议中添加对传统滑动窗口机制的拥塞信息转换机制,解决上述问题。
The TCP estimates network congestion according to the number of ACKs and uses the sliding window mechanism to adjust the size of the sending window to achieve congestion control.However,in MANET,the performance of traditional TCP is unsatisfactory both in terms of congestion judgment and congestion resolution.In recent years,various improvements to traditional TCP congestion control have been proposed.Among them,Semi-TCP adopts the idea of cross-layer design and accurately detects the congestion according to the data link layer buffer occupancy in the node,thereby greatly improving the network performance.Both adopt different congestion detection standards.When two protocols exist in one communication link,once congestion occurs,using different congestion detection standards will inevitably cause an adverse effect on subsequent congestion processing.Studies the problems that occur when TCP and Semi-TCP protocols coexist for the first time,and adds the mechanism of congestion information transfer to the traditional sliding window mechanism in Semi-TCP without changing the traditional TCP,which solves the above problems.
作者
郑涛
王菲
姜胜明
ZHENG Tao, WANG Fei, JIANG Sheng-ming(College of Information Engineering, Shanghai Maritime University, Shanghai 20130)
出处
《现代计算机》
2018年第12期3-8,共6页
Modern Computer
基金
国家自然科学基金(No.61472237
No.U1701265)
