Regions: A new architectural capability in networking

区域：网络中的新架构功能

• 批准号: 0137403
• 负责人: Karen Sollins
• 金额: $ 103.59万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0137403&HistoricalAwards=false
• 关键词: Regions; new; architectural; capability; networking

Naive pictures of the Internet frequently portray a small collection of hosts or LAN's connected by a "cloud" of connectivity. The truth is more complex. The IP-level structure of the Internet is composed from a large number of constituent networks, each of which differs in some or all of transmission technologies, routing protocols, administrative models, security policies, QoS capabilities, pricing mechanisms, and similar attributes. On top of this, a whole new structure of application-layer overlays and content distribution networks, equally diverse in the sorts of ways mentioned above, is rapidly evolving. Virtually any horizontal slice through the current Internet structure reveals a loosely coupled federation of separately defined, operated, and managed entities, interconnected to varying degrees, and often differing drastically in internal requirements and implementation. Intuitively, it is natural to think of each of these entities as existing in a region of the network, with each region having coherent internal technology and policies, and each region managing its interactions with other regions of the net according to some defined set of rules and policies.The thesis of the present proposal is that this basic, general notion of a region is a powerful tool for managing the increasingly complex demands on the Internet and its successors, and thus should made into an explicit, first-class component of the network architecture. It is suggested that the many uses of the region concept share a well-defined set of core ideas and operations, and that it is therefore useful to separate the concept of "region" from any specific use of the concept and provide it as an independent, reusable abstraction. It is further suggested that the region abstraction can be implemented as a concrete software entity, and that doing so will provide protocol designers and implementers at all levels of the stack with logically structured, scalable, high-performance access to an important classof functionality.The region is a generalization of a group and a bound in some space. The two defining concepts of a region are a set of contained members, which share some common invariants, and a boundary, which allows us to capture the notion of actions taken when entering and leaving the region. Furthermore, it is capable of self-adaptation to changes in its size or usage patterns, allowing the same abstraction to apply under widely differing demands on scalability, performance, and efficiency. Ideas are found useful in many places in networking to address problems such as scaling, distribution, efficiency, heterogeneity, cost recovery, and many others.It is proposed in this research to define and develop the region abstraction and explore its utility as a general mechanism in networking. The research will proceed through several phases of three interrelated activities. The first is the development and definition of the region abstraction itself, with focus on requirements, choice of capabilities, abstract operations, and related issues. The second is designing and building a prototype implementation of the region entity, with focus on appropriate algorithms and adaptation strategies. The third is to examine and validate the region concept through use in three example problems. The examples serve two purposes, to explore the utility of having regions available and to further refine and improve the definition of a region. They are chosen specifically to stress different aspects of the region abstraction.The intention is that the region is a neutral mechanism provided to address many problems, both within a single network layer and across layers. The research will lead to a better understanding of management of multiple layers and the impacts that one can have on another in a controlled way. The research is expected to lead to a framework for decision-making about adaptation to changes in size and usage patterns. Finally, the research is expected to provide a better understanding in each of the example areas of the problems that arise there and how to address them.

天真的互联网图片经常描绘了一小群主机或局域网，它们通过连接的“云”连接在一起。事实要复杂得多。因特网的IP级结构由大量组成网络组成，每个组成网络在传输技术、路由协议、管理模型、安全策略、服务质量能力、定价机制和相似属性的某些或全部方面不同。最重要的是，一种全新的应用层覆盖和内容分发网络结构正在迅速演变，在上面提到的各种方式上同样多样化。实际上，贯穿当前互联网结构的任何水平切片都揭示了一个松散耦合的联盟，这些实体由单独定义、运营和管理的实体组成，在不同程度上相互连接，并且在内部要求和实施方面往往截然不同。直观地，很自然地认为这些实体中的每一个都存在于网络的一个区域中，每个区域具有连贯的内部技术和策略，并且每个区域根据某组定义的规则和策略来管理其与网络的其他区域的交互。本提案的主题是，区域的基本、一般概念是管理对因特网及其后继者日益复杂的需求的强大工具，因此应该成为网络体系结构的明确的、一流的组件。有人建议，区域概念的许多用途都有一套明确界定的核心思想和业务，因此，将“区域”概念与该概念的任何具体用途分开，并将其作为一个独立的、可重复使用的抽象概念提供是有益的。进一步提出，区域抽象可以被实现为一个具体的软件实体，这样做将为协议栈各级的协议设计者和实施者提供对一类重要功能的逻辑结构化、可伸缩、高性能的访问。区域的两个定义概念是一组包含的成员，它们共享一些共同的不变量，以及边界，它允许我们捕获进入和离开区域时采取的操作的概念。此外，它能够自适应其大小或使用模式的变化，允许相同的抽象应用于对可伸缩性、性能和效率有很大不同的需求。在网络中的许多地方发现了有用的想法来解决诸如规模、分布、效率、异构性、成本回收等许多问题。本研究建议定义和发展区域抽象，并探索其作为网络中的一种通用机制的效用。这项研究将分三个相互关联的活动的几个阶段进行。首先是区域抽象本身的开发和定义，重点放在需求、功能选择、抽象操作和相关问题上。第二是设计和建立区域实体的原型实施，重点是适当的算法和适应战略。三是通过三道例题对区域概念进行检验和验证。这些例子有两个目的，一是探索提供区域的效用，二是进一步完善和改进区域的定义。选择它们是为了强调区域抽象的不同方面。目的是区域是一个中立的机制，用于解决单个网络层内和跨层的许多问题。这项研究将有助于更好地理解多个层次的管理，以及一个层次可能以受控方式对另一个层次产生的影响。这项研究有望形成一个关于适应大小和使用模式变化的决策框架。最后，预计这项研究将更好地了解每个范例领域中出现的问题以及如何解决这些问题。