Applied Metarouting Project

因特网的基本服务是连通性——允许位于不同的、自主管理的网络中的主机之间交换数据。互联网连接是使用动态路由协议实现的，该协议在成千上万的网络路由器之间交换可达性信息。当前的路由协议数量很少，不能很好地适应许多网络。这使得现有协议以高度复杂和扭曲的方式被迫投入使用，从而限制了网络设计的灵活性，增加了网络运营成本，降低了网络的鲁棒性水平。我们将此称为路由协议僵化问题。Griffin和Sobrinho最近提出了metarouting作为解决这个问题的潜在方法。元路由是基于设计一种元语言来规范路由协议的。在路由器上实现这种元语言将使网络运营商能够定义、实现和部署适合其网络需求的新协议。它还将允许网络研究人员在丰富的新路由协议空间中进行实验。mettarrouting论文的一个创新之处在于展示了如何定义元语言，从而可以自动验证协议规范，以保证协议收敛和无环路转发。当前的域间路由协议BGP （interdomain routing protocol， BGP）缺乏正确性，导致路由异常，且难以调试。在计量路由的理论草图和可用的、有效的实现之间有很大的差距。《支持案例》旨在缩小这一差距。我们寻求资金用于设计、开发和验证计量路由的第一个原型实现。这是一个具有挑战性的目标，需要解决许多难题，包括设计面向用户的元语言，编译元语言规范以实现高效，以及从当前路由协议实现中提取通用算法。我们的实现将建立在XORP （www.xorp.org）的现有代码基础上，XORP是一套开源路由协议，由伦敦大学学院的Mark Handley博士领导的一个项目开发。

The bedrock service of the Internet is connectivity --- allowing the exchange of data between hosts located in diverse, autonomously administered networks. Internet connectivity is implemented using dynamic routing protocolsthat exchange reachability information between tens of thousands of network routers. Current routing protocols are few in number and are not well suited for many networks. As a result, the existing protocols are pressed into service in highly complex and contorted ways, thus limiting the flexibility of network design, increasing the cost of network operations, and lowering the level of network robustness.We refer to this as the routing protocol ossification problem. Griffin and Sobrinho recently proposed metarouting as a potential solution to this problem. Metarouting is based on the design of a metalanguage for thespecification of routing protocols. Implementing such a metalanguage on a router would enable network operators to define, implement, and deploy new protocols that are tailored to the needs of their networks. It would also allow network researchers to experiment in a rich space of new routing protocols. One innovation of the metarouting paper was to show how a metalanguage can be defined so that protocol specifications could be automatically validated to guarantee both protocol convergence and loop-free forwarding. Lack of correctness in the current interdomain routing protocol (BGP) results in routing anomalies that are very difficult to debug. There is a large gap between the theoretical sketch of metarouting and usable, efficient implementations. This Case for Support is aimed at closing that gap. We seek funding for the design, development, and validation of the first prototype implementation of metarouting. This is a challenging goal that will require solutions to many difficult problems, including the design of a user-oriented metalanguage, compilation of metalanguage specifications to efficientimplementations, and extracting generic algorithms from current routing protocol implementations. Our implementation will build on the existing code base of XORP (www.xorp.org), a suite of open source routing protocols developed in a project led by Dr Mark Handley of UCL.