ANI/STI: Measurements, Models, and Simulation Scenarios for Internet Research

网络研究人员从互联网重要属性的心理模型开始工作。在模拟和实验中使用的场景揭示了这些心理模型的各个方面，通常包括以下一个或多个方面：（1）流存在很长时间并传输大量数据。简单的拓扑结构，如“哑铃”拓扑结构，有一个拥塞的链路，足以研究许多交通特性（2）拥塞链路上的流量共享一个小范围的往返时间（3）大多数交通通过链路是单向的（4）反向路径交通很少被忽略所有这些模型都可以深刻影响仿真和实验结果，因此评估研究，但没有一个被测量研究证实，有些是错误的。一些与现实的差异并不重要，因为它们不会影响模拟结果的有效性，简单的模型有助于人们理解系统的潜在动力学。然而，作为一个社区，我们还不知道模型的哪些方面会影响基本的系统行为，哪些方面可以安全地忽略。该项目旨在对现实网络模型的范围以及不同模型参数与网络性能的可能相关性建立更丰富的理解。缺乏良好的测量，缺乏评估测量结果并将其结果应用于模型的工具，以及缺乏基于这些模型的多样化和良好理解的模拟场景，阻碍了该领域的发展。该计划将直接解决网络研究人员在模拟和实验中使用的模型。在现有大量计量结果的基础上，并在必要时产生新的经验性结果，这将创造高质量的工具，以便利这一群体和更广泛的网络研究界进行持续的计量，从而使结果跟上互联网的高速变化。综合相关的测量结果将提供简洁的直观信息和一系列可供研究人员使用的模拟模型。本书将说明模型的各个方面如何影响模拟和实验。这项工作不会创建全球互联网的通用模型（这是一项巨大而不必要的任务）。相反，它将重点关注特定研究领域研究人员使用的模型，其动机是解决他们紧迫的建模问题。首先专注于小组自己的专业领域，特别是在路由器中的队列中建模与排队相关的机制，然后解决其他研究领域，帮助其他人改进他们的测量和测量工具，沿着产生的模型和仿真场景，并改善实验，模型和我们对仿真结果的共同理解之间的关系。

Networking researchers work from mental models of the Internet's important properties. The scenarios used in simulations and experiments reveal aspects of these mental models, often including one or more of the following: (1) Flows live for a long time and transfer a lot of data. Simple topologies, like the "dumbbell" topology, with one congested link, are sufficient to study many traffic properties(2) Flows on the congested link share a small range of round-trip times(3) Most traffic across the link is one-way (4) Reverse-path traffic is rarely congestedAll of these models can deeply affect simulation and experimental results, and therefore evaluations of research, but none of them are confirmed by measurement studies, and some are actively wrong. Some divergences from reality are unimportant, in that they don't affect the validity of simulation results, and simple models help people understand the underlying dynamics of systems. However, as a community we do not yet understand which aspects of models affect fundamental system behavior, and which aspects can safely be ignored. This project proposes to build a much richer understanding of the range of realistic network models, and of the likely relevance of different model parameters to network performance. The lack of good measurements, lack of tools for evaluating measurement results and applying their results to models, and lack of diverse and well-understood simulation scenarios based on these models, are holding back the field. This program will directly address the models used by network researchers in simulations and experiments. Building on the wealth of existing measurement results and generating new empirical results where needed, this will create high-quality tools to facilitate ongoing measurement by this group and the wider network research community, so that the results keep up with the Internet's high rate of change. Synthesizing the relevant body of measurement results will provide concise intuitions, and a range of simulation-ready models, for use by researchers. An illustration of how each aspect of the models can influence simulations and experiments will be given.This work will not create a universal model of the global Internet (an immense and unnecessary undertaking). Instead, it will focus on models used by researchers in specific research areas, motivated by addressing their pressing modeling concerns. Focusing at first on the group's own areas of expertise, particularly modeling congestion-related mechanisms at a queue in a router, and later address other research areas, help others improve their measurements and measurement tools, along with the resulting models and simulation scenarios, and improve the relationships between experiments, models, and our shared understanding of simulation results.