Abstract: Most of the available bandwidth measurement technologies are based on singlehop and the fluid model, which cannot get high accuracy in the situation of multihop path and bursty cross traffic. Therefore, a nonfluid model was analyzed and a method of parameters setting was introduced to reduce the impacts of packet size, cross traffic rate, probe traffic rate on measurement accuracy. A developed structure of packetpair, combined with setting the Time To Live (TTL) value, reduced the measurement error of packetpair spacings, which improved the robustness of the method in the context of a multihop path. The NS2 simulation results show that the measurement accuracy is improved by the parameter setting method based on nonfluid model and improved packet structure.

Key words: available bandwidth, non-fluid model, multi-hop path, cross traffic, measurement accuracy

摘要： 现有的可用带宽测量技术大多基于单跳链路和液体流模型，在突发背景流及多跳链路下测量精度较低。因此，分析了更符合网络实际的非液体流模型，提出了一种参数设置方法，减小了探测包长、探测速率、背景流速率及背景流包长等因素对测量精度的影响。在此基础上，改进了探测包对结构，该结构结合生存时间(TTL)值设置减小了探测包对间隔的测量误差，增强了带宽测量算法在多跳链路环境下的健壮性。仿真表明，基于非液体流模型的参数设置方法及改进的包对结构提高了可用带宽测量精度。

关键词: 可用带宽, 非液体流模型, 多跳链路, 背景流量, 测量精度