NETS: SMALL: Collaborative Research: Protocol Stacks Design and Evolution: The Role of Layering and Modularity

NETS：小型：协作研究：协议栈设计和演变：分层和模块化的作用

• 批准号: 1361771
• 负责人: Roch Guerin
• 金额: $ 25万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-10-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1361771&HistoricalAwards=false
• 关键词: NETS; SMALL; Collaborative; Research; Protocol

Network protocol stacks typically follow a multi-layer hierarchical architecture. What determines the required number of layers, or the number of protocols at each layer? The space of applications, services and user expectations (at the top layer) and the space of elementary functions (at the bottom layer) are constantly evolving -- how does this dynamic environment affect the organization of layered protocol stacks? What determines the evolvability of a protocol stack in the presence of changes? How does evolvability relate to other important system-wide properties such as robustness (the ability to deal with unexpected change), optimality and modularity? These are some of the high-level questions that this research project focuses on. Intellectual Merit: This research seeks to reexamine the fundamentals of protocols design and investigate the role of and dependencies between several central concepts: layering, modularity, complexity, robustness, optimality. The central theme in this research, however, is evolution -- networking architectures are not designed to work in a static environment. Applications, services, user expectations, communication and computing technologies, as well as the underlying economics, are all in a constant state of flux. Rather than rely on a single modeling framework, this research starts with two preliminary models, referred to as Stratum and Lexis. The two models share some features but are also significantly different and complementary. They both capture the time-varying character of a layered design process aiming to support a dynamic set of applications from an underlying set of (also dynamic) elementary functions. Stratum is more constrained than Lexis as it considers, first, a specific ordering for the available building blocks, and second, an endogenous model for the ``death rate'' of existing applications. Lexis, on the other hand, is more general and more abstract, and captures how a time-varying set of regular expressions can be constructed hierarchically from a time-varying alphabet, re-using simpler regular expressions as much as possible.The Stratum and Lexis models are initial steps towards developing a base understanding of what factors influence the evolvability and sustainability of protocols. With this base in place, further domain-specific insight can be developed and yield targeted guidelines for the design of future network protocols.Broader Impact: There are currently four large NSF-funded Future Internet Architecture (FIA) projects that pursue a ``clean-slate'' design approach for a future Internet that is more robust, secure, evolvable, etc. A goal of this research is to both inform and learn from the efforts of the four FIA projects.The broader impact of this project also includes the release of two extensible simulators (corresponding to Stratum and Lexis) that will allow students and instructors to experiment with how network architectures evolve in dynamic environments and under optimization objectives and constraints. No such tools are available today.Additionally, this project has a significant inter-disciplinary component in both its ?inputs and outputs.? Specifically, much of the prior work behind this research (inputs) has originated in economics, physics and evolutionary biology. Conversely, the project's results (outputs) are likely to be relevant to other disciplines such as software engineering, smart manufacturing and the science of organizations.

网络协议堆栈通常遵循多层层次结构。 是什么决定所需的层数或每一层协议数的数量？ 应用程序，服务和用户期望的空间（在顶层）和基本功能的空间（在底层处）正在不断发展 - 这种动态环境如何影响分层协议堆栈的组织？ 是什么决定了在存在变化的情况下协议堆栈的发展性？ 可发展性与其他重要的全系统属性（例如鲁棒性（应对意外变化的能力），最佳性和模块化有何关系？ 这些是该研究项目所关注的一些高级问题。 智力优点：本研究试图重新审查协议设计的基础知识，并研究几个中心概念之间的作用和依赖性：分层，模块化，复杂性，鲁棒性，最佳性。 但是，这项研究的中心主题是进化 - 网络体系结构并非设计用于在静态环境中工作。应用，服务，用户期望，通信和计算技术以及基本经济学都处于恒定状态。这项研究不是依靠单个建模框架，而是从两个初步模型开始，称为Stratum和Lexis。 这两个模型具有某些功能，但也有显着差异和互补的。 他们都捕获了分层设计过程的时变特征，旨在支持一组基础（也是动态）基本功能的动态应用程序集。比Lexis更受限制，因为它首先是对可用构件的特定订购，其次是现有应用的``死亡率''的内源性模型。 另一方面，Lexis更一般，更抽象，并捕获了如何通过随时间变化的字母表进行层次构造的一组正则表达式，并尽可能尽可能多地使用更简单的正则表达式。地层和Lexis模型是针对哪些因素影响了方案的基本了解，该模型的初始步骤是对协议的发展能力和可持续性的基础理解。 有了这个基础，可以开发出进一步的特定领域的见解，并产生针对未来网络协议设计的目标指南。Boader的影响：目前有四个大型NSF资助的未来Internet架构（FIA）项目，这些项目追求“清洁式封闭”的“清洁式''''''''''''''设计方法，这些互联网为未来的互联网提供了一种更加可靠，安全，可靠性的范围。项目还包括发布两个可扩展的模拟器（对应于层和lexis），这些模拟器将使学生和讲师可以尝试在动态环境以及优化目标和约束下如何在动态环境中发展网络体系结构。 今天没有这样的工具可用。在此方面，该项目在其输入和输出中都具有重要的跨学科组件。 具体而言，这项研究（输入）背后的许多先前工作都起源于经济学，物理和进化生物学。 相反，项目的结果（输出）可能与其他学科有关，例如软件工程，智能制造和组织科学。