ITR/ANI: Addressing Fundamental Issues for Robust Internet Performance

互联网在技术、管理和容量方面是庞大的、分散的和异构的。互联网成功的核心源于它对许多架构原则的坚持，其核心理念是网络应该努力实现稳健且经常运行良好的性能水平。在各种条件下实现这一目标的主要技术之一是使互联网协议和机制具有适应性，以便它们能够自我调整，以便在它们发现自己的任何情况下都能很好地工作。这种方法非常成功。然而，一些设计为在大范围条件下足够好的机制现在必须或很快将在超出其有效动态范围的状态下运行。例如，TCP 拥塞控制机制需要重新审视未来的互联网，包括即将到来的高速路径和即将到来的低速路径（例如，有损无线链路）。同样，该体系结构优雅地容忍故障的能力不会扩展到新形式的故障，例如错误配置的路由信息或故障的中间盒，也不会扩展到分布式压力，例如闪光人群、快速传播的蠕虫或拒绝服务（DoS）洪水。如果我们将稳健性视为网络在各种条件下良好运行的能力，特别是在一个非常庞大、不断增长和不断变化的网络中，那么我们认为未来互联网的稳健性显然是有危险。在这个提案中，我们强调多方面的鲁棒性方法：1）在极端环境下的鲁棒性能，例如非常高的速度和高度可变的延迟，这需要重新思考当今的拥塞控制机制。2）在存在新形式的故障时的鲁棒性能，无论是在网络层的鲁棒路由方面，还是在应用层的应对现在广泛部署的中间件（这些中间件已挤入架构）。这将需要研究更广泛的故障推断概念。3）在分布式压力下的鲁棒性能，无论是恶意的（拒绝服务洪水；拥塞控制作弊者）还是拥挤的（闪电人群）。这需要了解网络的拓扑和流量聚合的构成，再加上网络内部部署的新控制机制。实现这些目标的部分方法是完善现有协议和机制，并研究新的协议和机制。但研究人员还强调，通过在短时间尺度（通过分布式操作监控）和长时间尺度（通过对已部署协议实现的诊断探测）上检测初期故障来实现稳健的性能。当然，这些主题并没有解决互联网架构面临的全部挑战，但它们确实解决了保持和增强互联网稳健性的一些核心问题。从某种意义上说，拟议的研究是保守的，因为我们根据当前互联网架构内的工作来构建它，而不是提倡一种干净的方法。然而，研究人员认为，在某些方面，这种保守的方法使得研究更加基础，而不是更少。干净的表方法虽然更整洁，更有利于轻松探索基本原理，但忽略了不同机制一旦集成到真正的大规模网络中如何最终相互作用的关键现实。

The Internet is large, decentralized, and heterogeneous in its technology, administration and capacity. The core of the Internet's success arises from its adherence to a number of architectural principles, central to which is the notion that the network should try to achieve a robust, very often works pretty well level of performance. One of the main techniques for achieving this across a wide range of conditions is making Internet protocols and mechanisms adaptive, so that they self-tune to work reasonably well in whatever circumstances they find themselves.This approach has been extremely successful. However, some of the mechanisms, designed to be good enough across a large range of conditions, must now or will soon operate in regimes beyond their effective dynamic range. For example, TCP congestion control mechanisms require revisiting for tomorrow's Internet, both the coming high speed paths, and the coming low speed paths (e.g., lossy wireless links). Similarly, the architecture's ability to gracefully tolerate failures does not extend to new forms of failures, such as misconfigured routing information or malfunctioning middle-boxes, nor to distributed stresses, such as flash crowds, rapidly-spreading worms, or denial-of-service (DoS) floods.If we view robustness as the ability of the network to function well over a wide spectrum of conditions particularly given a very large, ever-growing and ever-changing network then we argue that the robustness of the future Internet is clearly at risk. In this proposal, we emphasize a multifaceted approach to robustness:1) Robust performance in the presence of extreme environments such as very high speed and highly variable delay, which requires rethinking today's congestion control mechanisms.2) Robust performance in the presence of new forms of failure, both at the network layer, in terms of robust routing, and at the application layer, in terms of coping with the now widespread deployment of middleboxes that have elbowed their way into the architecture. This will require investigating broader notions of fault inference.3) Robust performance in the presence of distributed stresses, both malicious (denial-of-service floods; congestion control cheaters) and merely teeming (flash crowds). This will require an understanding of the network's topology and the makeup of traffic aggregates, coupled with new control mechanisms deployed inside the network.Part of the approach to these is to refine existing protocols and mechanisms, and investigate new ones. But the researchers also emphasize achieving robust performance by detecting incipient failures, on both short time scales (via distributed operational monitoring) and long time scales (via diagnostic probing of deployed protocol implementations).While certainly these topics do not address the full range of challenges facing the Internet architecture, they do address some of the core issues in preserving and enhancing the Internet's robustness. In one sense, the proposed research is conservative, in that we frame it in terms of working within the current Internet architecture, rather than advocating a clean sheet approach. The researchers argue, however, that in some ways this conservative approach makes for research that is more fundamental rather than less. The clean sheet approach, while more tidy and much more conducive to easy exploration of basic principles, misses the crucial reality of how different mechanisms wind up interacting once integrated into a truly large-scale network.