General Purpose Routers for the Next Generation Internet

在过去几年中，将功能从终端主机推向网络路由器的压力很大。无论人们将产生的系统称为路由器、应用程序网关、活动网络、代理，甚至是拓扑感知服务器，人们都认识到了一个总的趋势：决定如何处理分组的逻辑随着时间的推移变得越来越复杂。有观点认为，这种趋势继续发展的潜力几乎是无限的，这就引出了一个问题：下一代互联网中路由器的重要特性是什么？项目的答案是一种新的路由器体系结构，他们称之为通用路由器(GPR)，支持任意复杂的转发逻辑。GPR架构有六个独特的特点：性能：提供下一代互联网所需的吞吐量。可扩展：可轻松扩展以支持新的转发功能，而不会影响性能。可扩展：可扩展到相对较大的大小，大约为100 Gbps端口。开放：硬件和软件应该是开放的，这样任何人都可以构建或扩展路由器。商品组件：使用市场上可获得的组件实现。健壮性：足够健壮，足以容忍编程错误和恶意攻击。该项目的底线是，该项目认识到路由器需要从封闭的专用网络设备转变为开放的通用计算/通信系统。实现这一转变的核心挑战是，在使用商业硬件组件和商业操作系统的同时，同时支持日益复杂的转发逻辑和高性能。GPR架构通过两项关键创新实现了这一点。更好地集成路由器的交换能力和计算周期。该项目预计，这将显著改善可伸缩性，并将仅需要最小处理周期的数据包的性能提高数量级。通过路由器的路径层次结构，从完全在硬件中实现的快速/固定路径到完全在软件中实现的慢速/可编程路径，但也包括利用改进的周期和交换集成的中间路径。除了实施GPR架构--并解决这样做将带来的配置、调度和资源管理问题-该项目还将设计和实施几个新的应用：在因特网的不同假设区域之间转换的边缘路由器。特别值得注意的是，该项目将为包括瘦设备(例如嵌入式系统和低功率设备)的深度嵌套网络开发路由器功能。路由器需要承担通常由终端节点承担的一些责任。一种可扩展的显示系统，由一组并行显示处理器(和相关的帧缓冲器)组成，每个处理器负责墙上大小的显示器的某个区域。作为该数组的前端的路由器--即，将其连接到图形源--必须对包含图形指令的分组进行分段，并将每个分段转发到正确的处理器。实施隔离并保护站点内的主机不受其他主机影响的内部防火墙。与位于站点边缘的防火墙不同，这样的路由器必须对用户进行身份验证、实施访问控制、记录使用情况并实施入侵检测。

There has been tremendous pressure over the last several years to push functionality from end hosts onto network routers. Whether one calls the resulting systems routers, application gateways, active networks,proxies, or even topology-aware servers, a general trend was recognized: the logic that decides how to process packets has grown more and more complex over time. It is a contention that the potentialfor this trend to continue is almost unlimited, which suggests the question: what are the important properties for routers in the next generation Internet? The projects answer is a new router architecture, which theycall a general purpose router (GPR), that supports arbitrarily complex forwarding logic. The GPR architecture has six unique features: Performance: Provides the throughput required by the next generation Internet. Extensible: Easily extended to support new forwarding functions without compromising performance. Scalable: Scales to relatively large sizes, on the order of a hundred of Gbps ports. Open: The hardware and software should be open so anyone can build or extend a router. Commodity Components: Implemented using commercially available components. Robustness: Robust enough to tolerate programming mistakes and malicious attacks.The bottom line is that the project recognizes a need for routers to move from being closed, special-purpose network devices to being open, general-purpose computing/communication systems. The central challengein making this shift is to simultaneously support increasing complex forwarding logic and high performance, while using commercial hardware components and commercial operating systems. The GPR architectureachieves this through two key innovations. Better integration of the router's switching capacity and compute cycles. The project expects this to result in significantly better scaling properties, and an order of magnitude improvement in performance for packets that require only minimum processing cycles. A hierarchy of paths through the router, ranging from fast/fixed paths implemented entirely in hardware to slow/programmable paths implemented entirely in software, but also including intermediate paths that exploit the improved integration of cycles and switching.In addition to implementing the GPR architecture---and solving the configuration, scheduling, and resource management problems that doing so will entail---the project will design and implement several novelapplications: Edge routers that transition between different assumption regions of the Internet. Of particular note, the project will develop router functionality for deeply nested networks that include thin devices (e.g., embedded systems and low-power devices). The router needs to subsume some of the responsibility usually taken by the end node. A scalable display system that consists of an array of parallel display processors (and associated frame buffers), each of which is responsible for some region of a wall-sized display. The router that serves as a front-end to this array---i.e., connects it to a graphics source--must fragment packets containing graphics directives and forward each fragment to the correct processor. An internal firewall that implements enclaves and protects hosts within a site from each other. Unlike a firewall that sits at the edge of a site, such a router must authenticate users, enforce access control, log usage, and implement intrusion detection.