NeTS: Small: Automated Diagnosis and Root Cause Analysis of Internet Problems

可靠的互联网性能和可用性对于许多现有和未来的网络应用至关重要。虽然互联网在大多数时间对大多数人来说都运行得很好，但几乎每个人都经历过中断和服务降级，使网络无法使用，我们远远没有达到关键服务所需的可靠性。改善互联网连接需要采取行动，消除所有造成网络不畅通和性能低下的根源。 研究界在理解和开发技术以解决由于BGP（边界网关协议）路由收敛而导致的短期中断方面取得了实质性进展。然而，在减少长期中断和路线配置错误的影响方面取得的进展要小得多。 尽管很罕见，但这些事件对整体网络可用性有很大的影响，因为修复是在人类的时间尺度上发生的。 此外，由于错误配置和无效的路由选择，许多用户遭受使用次优（高延迟或有损）路径到网络服务的痛苦。 受影响的ISP或服务的操作员在每一步都经常遇到障碍：确定问题存在，定位问题的根本原因，以及影响修复。该项目的研究人员将开发一个系统，将这个主要是手动的故障排除过程转变为完全自动化的过程。 研究的目标是可以实时识别持续的停机和性能问题，而不是现在的几个小时。 虽然自动诊断和根本原因的识别从根本上说是困难的，该项目将受益于互联网测量技术的最新进展，特别是反向路径测量，提供了一个比以往任何时候都更完整的互联网拓扑结构。智力优点：该研究项目的目标是改变互联网上的网络诊断范式-从盲目到知情。 网络故障排除的最新技术是使用ad-hoc技术。 例如，它是常见的NANOG（北美网络运营商？组）邮件列表，供运营商发布请求，要求其他运营商手动发布跟踪路由并报告它们，以识别网络异常。 因此，网络可以受益于连续操作的服务，该服务不仅可以实时检测网络问题，而且还可以以路由器的粒度识别行为不端的网络元件。 部署功能诊断系统也面临许多挑战，研究人员将使用以下关键组件来解决这些挑战。 首先，该项目将产生一个可扩展的测量系统，该系统将综合不同技术的测量结果，以实时提供路由行为的快照。 第二，研究将集中在开发一个通用的理论，互联网路径的变化，这将有助于模拟路由事件的传播，并确定候选集负责AS（自治系统）。第三，研究人员将开发推理技术，即使测量数据不完整或受到瞬态动力学的影响，也可以对测量数据进行操作，并在广域范围内识别故障和路径变化的起源。更广泛的影响：我们的社会越来越依赖互联网提供关键的电信服务，如家庭健康监测，e-911，智能电网等。 当互联网不可用或效率低下时，它不再仅仅是一种不便。 如果这个项目成功，它将帮助运营商解决互联网中不可用和配置错误的主要根源，使所有用户受益。 此外，由于缺乏自动化工具，运营商目前花费大量时间追踪个别中断和性能配置错误;这提高了小型ISP的进入门槛，最终提高了每个人的互联网服务成本。

Reliable Internet performance and availability are essential for many existing and future network applications. While the Internet works well enough most of the time for most people, nearly everyone has experienced outages and service degradation that make the network unusable, and we are far from five nines of reliability that critical services require. Improving Internet connectivity requires action against all sources of unavailability and poor performance. The research community has made substantial progress toward understanding and developing technologies to address short-term outages due to BGP (border gateway protocol) routing convergence. However, much less progress has been made at reducing the impact of long-term outages and route misconfiguration. Despite being rare, these events have a large impact on overall network availability because repairs happen on a human timescale. Additionally, many users suffer from the use of sub-optimal (high latency or lossy) paths to network services due to misconfigurations and ineffective route selection. Operators at an affected ISP or service often encounter stumbling blocks at each step: identifying that a problem exists, localizing the root cause of the problem, and affecting a repair. The researchers on this project will develop a system to transform this largely manual troubleshooting process into a fully automated one. The goal of the research is that persistent outages and performance problems can be identified in real-time, rather than today's matter of hours. While automated diagnosis and identification of root cause is fundamentally hard, the project will benefit from dramatic recent progress in Internet measurement technologies, specifically reverse path measurement that provides a much more complete picture of the Internet topology than ever before.Intellectual Merit: The goal of the research project is to change the paradigm of network diagnosis on the Internet -- from blind to informed. The state of art with network troubleshooting is to use ad-hoc techniques. For instance, it is common occurrence on the NANOG (North American Network Operators? Group) mailing list for operators to post requests asking other operators to manually issue traceroutes and report them in order to identify network anomalies. The network could thus benefit from a continuously operated service that can not only detect network problems in realtime but also identify misbehaving network elements at the granularity of routers. There are also a number of challenges to deploying a functional diagnosis system, and the researchers will address them using the following key components. First, the project will produce a scalable measurement system that will synthesize measurements from different techniques to provide snapshots of routing behavior in real-time. Second, the research will focus on developing a general theory of Internet path changes that will help model the propagation of routing events and identify the candidate set of responsible ASes (autonomous systems). Third, the researchers will develop inference techniques that will operate on measured data and identify the origin of failures and path changes in the wide area even when the measurement data is incomplete or subject to transient dynamics.Broader Impact: Our society is increasingly relying on the Internet for critical telecommunications services, such as home health monitoring, e-911, smart grids, and so forth. It is no longer simply an inconvenience when the Internet is unavailable or inefficient. If this project is successful, it will help operators address the major sources of unavailability and misconfigurations in the Internet, benefiting all of its users. In addition, because of a lack of automated tools, operators currently spend huge amounts of time chasing down individual outages and performance misconfigurations; this raises the barrier to entry for small ISPs, ultimately raising the costs of Internet service for everyone.