一种基于TCP时间戳的包对算法的带宽测量方法

利用包对算法,结合TCP协议的时间戳机制,设计并实现了一种端到端带宽测量方法.该方法利用分组的时间戳,计算背靠背的两相邻分组到达接收端和应答返回发送端的时间差,可等效为分组瓶颈链路经历的时间,利用分组大小与时间差的比值求得瓶颈链路的带宽,即为端到端的带宽;引入离散化低通滤波器,滤除突发的干扰流量,筛选出有效的网络带宽,滤波器算法实现简单;利用互联网普遍使用的TCP协议,测量一般不受各网络节点安全访问控制的限制,具有很好的适应性,同时能为带QoS要求网络传输控制提供服务.实验结果表明,采用带宽测量方法测得的带宽与实际带宽基本吻合.

A Bandwidth Measurement Method Based on TCP Timestamp and Packet-pair Algorithm

Combined with packet-pair algorithm and TCP timestamp mechanism, an end-to-end bandwidth measurement method is proposed. The timestamps of two consecutive back-to-back packets are used to calculate the intervals of packets arriving at the receiver and acknowledgements returning to the sender, the duration when the segments pass through the bottleneck link is also determined, so the bandwidth of the bottleneck link is the quotient of segment size and the duration, namely the end-to-end bandwidth. The discrete-time low pass filter is employed to (eliminate) the bursty cross traffic and filter out the valid bandwidth, and the implementation is very simple. As TCP is widely used in the Internet, this method is free from the limitation of security access control of network nodes and achieves good adaptability, and also meets the QoS requirement of network transfer control. The experimental results show that the measured bandwidth by using bandwidth measurement method consists with the actual bandwidth.