ITR/ANI: Addressing Fundamental Issues for Robust Internet Performance

互联网规模庞大、分散，在技术、管理和容量上都是异质的。互联网成功的核心来自于它对一些架构原则的坚持，这些原则的核心是网络应该努力实现强大的、经常工作得相当好的性能水平。要在各种条件下实现这一点，主要技术之一是使互联网协议和机制自适应，以便它们自我调整，以便在任何情况下都能相当好地工作。这种方法非常成功。然而，有些机制被设计成在很大范围的条件下都足够好，现在必须或很快就会在超出其有效动态范围的制度下运行。例如，TCP拥塞控制机制需要重新访问未来的互联网，既包括即将到来的高速路径，也包括即将到来的低速路径(例如，有损耗的无线链路)。同样，该体系结构容错故障的能力不会扩展到新的故障形式，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，例如闪存拥挤、快速传播的蠕虫或拒绝服务(DoS)洪水。如果我们将健壮性视为网络在各种条件下正常运行的能力，特别是在给定一个非常大、不断增长和不断变化的网络的情况下，那么我们认为未来互联网的健壮性显然处于危险之中。在该方案中，我们强调一种多方面的稳健性方法：1)在极端环境下的稳健性能，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)在存在新的故障形式的情况下的稳健性能，无论是在网络层的稳健路由方面，还是在应用层，在应对现在广泛部署的中间盒方面，这些中间盒已经挤进了体系结构。这将需要研究故障推理的更广泛的概念。3)在存在分布式压力的情况下的稳健性能，既有恶意的(拒绝服务洪水；拥塞控制作弊者)，也有仅仅是拥挤的(快闪人群)。这将需要了解网络的拓扑结构和流量聚合的组成，以及网络内部部署的新控制机制。实现这些的方法之一是改进现有协议和机制，并研究新的协议和机制。但研究人员也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(通过对部署的协议实现的诊断探测)检测早期故障来实现稳健的性能。虽然这些主题肯定没有解决互联网架构所面临的全部挑战，但它们确实解决了在保持和增强互联网的稳健性方面的一些核心问题。在某种意义上，拟议中的研究是保守的，因为我们将其框架置于当前互联网架构内，而不是倡导一刀切的方法。然而，研究人员认为，在某些方面，这种保守的方法有助于更基础的研究，而不是更少。不留痕迹的方法虽然更整洁，也更有利于探索基本原则，但它忽略了一个关键现实，即一旦整合到一个真正的大规模网络中，不同的机制最终是如何相互作用的。

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.