Collaborative Research: Beyond BGP: Flexible and Scalable Interdomain Routing (BGGP)

域间路由执行将Internet拓扑的各个部分粘合在一起以创建连接的数据传输基础设施的关键功能。如今，这一关键功能由边界网关协议(BGP)[RFC1771]执行，该协议建立自治系统(AS)之间的可达性信息。然而，尽管它很重要，目前的测量和分析并没有导致对BGP的动态、压力下的性能、根本弱点和潜在的断点(如果有的话)的基本了解。虽然最近几年已经建立了一些数据采集点[ipe，routeview]，但这些测量点收集的路由数据与测量伪像[ftntalk]混合在一起，因此数据不一定反映协议在实际操作中的行为。为了使Internet继续其前所未有的增长，域间路由协议必须继续发展以满足不断增加的、有时甚至是相互矛盾的要求。人们普遍认为，当前的BGP路由协议可能无法满足其新的要求(例如，适应站点多宿主使用的急剧增加，这将使路由表从最佳的小尺寸[Huston：Scale：2001])。BGP通常被认为即将达到其使用寿命的尽头，尽管这还没有通过分析或测量来证实[Nimrod，irtfrr，Huitema：IPNG，Huston：Scale：2001]。由于缺乏对问题的共同理解，也缺乏足够的数据和分析，对于BGP在哪里/何时崩溃以及应该做什么(如果有的话)，没有达成共识。为了解决上述域间路由面临的关键问题，研究人员组建了一支拥有研究和运营经验以及网络协议、算法、建模和分析专业知识的团队。研究人员确定了全球路由必须满足的以下基本技术要求：它必须进行扩展以应对(用户数量和连接的丰富性)的增长；安全和弹性是关键问题，因此它必须在不断增加的故障和攻击面前继续运行；它必须能够充分利用丰富的互联网连接；它必须允许网络运营商应用各种策略约束和实施者在需要时轻松扩展协议的功能。基于上述标准，研究人员提出了以下3个步骤来应对这一挑战。(1)制定测量方法并收集必要的数据，以了解当前的BGP操作、其管理费用、压力下的动态、潜在的脆弱性和功能上的不足。这项研究将基于现有数据中缺乏的精确要求来进行测量，例如不通过易受攻击的多跳链路收集数据[ftntalk]。俄勒冈大学的一项新努力，与这项提议分开，如果得到资助，就是测量伙伴。(2)在我们的测量和分析的指导下，评估了几种建议的设计方法，包括通过修补BGP来满足需求，通过类似Nimrod的[Nimrod]Maps方法，通过两种不同的方法来处理多宿主可伸缩性，以及通过完全替代BGP的Clean Slate方法。这些方法中的每一种都强调域间路由问题的不同方面。研究人员认为，在许多所需的技术要求之间存在根本性的权衡，而这些权衡目前还没有被很好地理解。将测量和严谨的分析与包括运营专业知识在内的团队相结合，将使这些权衡清晰可见。(3)在数据分析和设计评估的基础上，研究人员将提出最终的方法作为前进的建议。通过上述步骤的反复，预计拟议的研究工作将对当前的域间路由操作、其动态和弹性(或缺乏)以及脆弱性产生新的理解；还将产生一种新的分析，利用直接和密集的测量和操作知识来捕捉域间路由需求之间的基本权衡；并将就如何满足未来因特网的域间路由需求得出结论。

Interdomain routing performs the critical function of gluing together individual pieces of the Internet topology to create a connected data delivery infrastructure. Today this critical function is performed by the Border Gateway Protocol (BGP) [rfc1771] which establishes reachability information among Autonomous Systems (ASes). However despite its importance, current measurements and analysis have not led to a basic understanding of BGP's dynamics, performance under stress, fundamental weaknesses, and potential breaking points (if any). Although a few data collection points have been set up in the last few years [ipe,routeviews], the routing data collected by these measurement points are mixed with measurement artifacts [ftntalk], thus the data do not necessarily reflect the protocol's behavior in actual operation. In order for the Internet to continue its unprecedented growth, the interdomain routing protocol must continue to evolve to meet ever increasing and sometimes contradictory requirements. There is a general belief that the current BGP routing protocol may be unable to meet its new requirements (for instance, accomodating the sharp increase in use of site multi-homing, which keeps routing tables from optimally small sizes[huston:scale:2001]). BGP is generally thought to be reaching the end of its useful lifetime, although this has not been validated by analysis or measurements [nimrod,irtfrr,huitema:ipng,huston:scale:2001]. Due to the lack of a shared understanding of the problem and lack of sufficient data and analysis, there is no consensus on where/when BGP collapses and what (if anything) should be done. To address the above critical questions facing interdomain routing, the researchres have assembled a team with research and operational experience, and expertise in network protocols, algorithms, modeling and analysis. The resarchers have identified the following fundamental technical requirements that the global routing must meet: it must scale in order to handle the growth (both in the number of users and in the richness of connectivity); security and resilience are critical issues, so it must continue to function in face of ever increasing faults and attacks; it must be able to fully utilize the rich Internet connectivity; and it must both allow network operators to apply various policy constraints and implementors to easily extend the protocol's functionality when needed. Based on the above criteria the researchers propose to tackle the challenge with the following 3 steps. (1) Develop measurement methodologies and collect data necessary to understand the current BGP operation, its overhead, dynamics under stress, potential vulnerabilities, inadequacies in functionality. The research will base this measurement effort on precise requirements that isidentiied as lacking in existing data, such as for the data not to be collected over vulnerable multihop links [ftntalk]. A new effort at University of Oregon, separate from this proposal, is the measurement companion, if funded. (2) Guided by our measurement and analysis, evaluate several proposed design approaches, including meeting the requirements by tinkering with BGP, by a NIMROD-like [nimrod] maps-approach, by two different approaches to handling multihoming scalability, and by a Clean Slate approach of a complete BGP replacement. Each of these approaches emphasizes different aspects of the interdomain routing problem. The researchers believe there are fundamental trade-offs between many of the desired technical requirements and that these trade-offs are currently not well understood. The combination of measurement and rigorous analysis with a team including operations expertise will bring these trade-offs into clear view. (3) Based on the data analysis and design evaluations the researchers will produce a final approach as the recommendation for moving forward. Through iterations of the above steps, the proposed research undertaking is expected to produce new understanding of current interdomain routing operations, their dynamics and resilience (or lack of it), and vulnerabilities; a new analysis will also be produced that draws on direct and intensive measurement and operations knowledge to capture the fundamental trade-offs among interdomain routing requirements; and a conclusion will be reached on how to meet the future Internet's interdomain routing needs.