Measurement-in-the-Middle

该项目引入了一种新的测量和分析方法，可用于根据在网络内单点进行的测量来表征端到端性能测量(例如路径上的损耗和延迟)以及内部网络特征(例如在远距离路径段上经历的损耗)。建议的“中间测量”方法使用在此单一测量点收集的带有时间戳的数据包级跟踪，以及基于概率状态的发送器/接收器模型和统计推断技术来推断端到端的性能测量。这些度量包括源、目的地和测量点之间的路径上的损耗和延迟，以及这些路径的部分路径上的损耗和延迟。本项目中进行的研究将开发和分析(通过建模、模拟和实证研究)这种新的网络性能测量和分析方法所需的理论基础和实际考虑因素。从网络中的单个点推断端到端和路径部分性能的能力具有许多优势。最重要的是，因为测量是在中间进行的，所以可以测量大量不同的源/目的地对的端到端行为，而不必检测单独的发送者和接收者。这项研究将开发一种全新的网络测量方法，使网络运营、工程和研究用户能够测量比过去更大、更多样化的网络流量组合。除了更全面地表征网络流量之外，更丰富的测量集和对网络流量的更好理解还可以在改进网络管理、网络建模和网络/协议设计方面发挥重要作用。

This project introduces a new measurement and analysis methodology that can be used to characterize end-end performance measures (such as loss and delay along a path) as well as internal network characteristics (such as loss experienced along distant path segments) from measurements taken at a single point within the network. The proposed "measurement-in-the-middle" approach uses time-stamped, packet-level traces gathered at this single measurement point together with probabilistic state-based sender/receiver models and statistical inferencing techniques to infer end-end performance measures. These metrics include the loss and delay along paths between a source, destination, and measurement point, and along portions of these paths as well. The research performed in this project will develop and analyze (through modeling, simulation, and empirical study) the theoretical foundations and practical considerations needed for this new approach towards network performance measurement and analysis. The ability to infer end-to-end and path-portion performance from a single point within the network has many advantages. Most importantly, because measurements are taken "in-the-middle," the end-end behavior of a large and diverse mix of source/destination pairs can be measured, without having to instrument individual senders and receivers. This research will develop a fundamentally new approach to network measurement methodology that will allow network operations, engineering and research users to measure a larger, and more diverse, mix of network traffic than has been possible in the past. In addition to more fully characterizing network traffic, a richer set of measurements and a better understanding of network traffic can also play an important role in improved network management, network modeling, and network/protocol design.