CAREER: Flexible Strategies for Internet Content Distribution

职业：互联网内容分发的灵活策略

• 批准号: 0093296
• 负责人: John Byers
• 金额: --
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0093296&HistoricalAwards=false
• 关键词: CAREER; Flexible; Strategies; Internet; Content

The emergence of new technologies for content distribution including content delivery networks (CDNs, end system multicast, distributed content exchange and application-level anycast are fundamentally changing the relationships between consumers and producers of digital content. Whereas traditional approaches to content delivery are predicated on point-to-point connections from a client to a single origin server, these new mechanisms for content distribution fundamentally undermine the assumptions inherent in that model. For example, CDNs redirect clients to a number of equivalent replica servers, while end system multicast goes further and blurs the distinction between client and server by requiring that every participant who wishes to access content serve content as well. To illustrate this point, consider the access graph plotting the flow of TCP connections serving a popular document through the network at an instant in time. Until very recently, this graph could easily be characterized as forming a hub-and-spoke topology with the hub at the origin server; now its complex structure is little known except perhaps to network engineers within the CDNs themselves. Broadly, the researcher's interests lie in characterizing the impact that new and increasingly distributed content delivery mechanisms will have on network traffic, resource management and the design of network protocols. In the research component of the researcher's career development program, he focuses on strategies for addressing the challenges and opportunities that distributed content delivery mechanisms will place on reliable transport protocols. In particular, the complex one-to-many and many-to-many relationships between consumers and producers of digital content will place strain on transport protocols such as TCP, as those protocols are not designed to accomodate the fluid interactions which will take place when users have a multiplicity of service options. The researcher argues for lightweight reliable transport services designed for maximum flexibility which can accomodate connection preemption, connection suspension, connection migration and connection aggregation. While these considerations are fundamental , they have not been carefully studied in the context of TCP because of daunting technical hurdles, complexity, and absence of a driving need. The researcher brings new techniques to bear on the problem, as the proposed work leverages his experience with fast forward error correcting coding techniques which he has applied in the domain of reliable multicast [11] and downloading digital content from multiple mirror sites in parallel [10]. In some of the settings considered, such as dynamic server selection and redirection, the flexibility which the proposed techniques afford can be considered to be a performance optimization, but in other settings, such as providing reliability for end system multicast, the researcher argues that the flexible services proposed are essential to delivering high performance. The proposed educational aspect of the researcher's career development program focuses on enhancing the undergraduate and graduate student experience in his department and building a stronger basis for industrial and inter-institutional networking research collaborations in the Boston area. Proposed activities center around ongoing projects to promote undergraduate involvement in networking research; to enhance the department's networking curriculum; and to encourage students to participate in the computer science community outside of the university, whether by volunteering at a community outreach program or by becoming involved in local organizations of computer scientists. An exciting initiative which the researcher is e actively involved in and which will help achieve these goals is the institution of a center for networking research at Boston University.

新技术用于内容分布的出现，包括内容交付网络（CDN，End System Multicast，分布式内容交换和应用程序级别的任何广播，从根本上改变了消费者与数字内容生产者之间的关系。而传统的内容交付方法是在Point上鉴定的 - 从客户端到单个原始服务器的点连接，这些用于内容分布的新机制从根本上破坏了该模型固有的假设。模糊了客户和服务器之间的区别，要求每个希望访问内容的参与者也可以说明这一点。直到最近，该图可以很容易地将其表征为在Origin Server上使用轮毂形成轮毂和辐条拓扑。现在，它的复杂结构鲜为人知，除了可能是CDN本身内的网络工程师。 从广义上讲，研究人员的兴趣在于表征新的和日益分布的内容交付机制对网络流量，资源管理和网络协议设计的影响。 在研究人员职业发展计划的研究组成部分中，他专注于解决分配内容交付机制的挑战和机遇的策略，这些挑战和机遇将置于可靠的运输协议上。 特别是，消费者和数字内容生产者之间的复杂一对多和多一对多的关系将构成运输协议，例如TCP，因为这些协议并非旨在适应当时会发生的流体互动用户具有多种服务选项。 研究人员认为，轻巧的可靠运输服务旨在最大程度地灵活性，这可以容纳连接抢先，连接悬架，连接迁移和连接聚合。 尽管这些考虑是基本的，但由于技术障碍，复杂性和缺乏驾驶需求，因此尚未在TCP的背景下进行仔细的研究。 研究人员为问题带来了新的技术，因为拟议的工作利用了他在可靠的多播[11]中应用的快进错误纠正编码技术的快进错误，并从并行下载了多个镜像站点的数字内容[10 ]。 在某些考虑的设置（例如动态服务器选择和重定向）中，提议的技术提供的灵活性可以被认为是性能优化，但是在其他设置中，例如为最终系统多播提供可靠性，研究人员认为提出的灵活服务对于提供高性能至关重要。 研究人员职业发展计划的拟议教育方面着重于增强本科和研究生在其部门的经验，并为波士顿地区的工业和机构间社交研究合作建立更强的基础。 拟议的活动围绕正在进行的项目中心，以促进本科参与网络研究的参与；增强部门的网络课程；并鼓励学生参加大学以外的计算机科学界，无论是在社区推广计划中志愿服务还是参与计算机科学家的本地组织。 研究人员积极参与了一项令人兴奋的倡议，并将有助于实现这些目标，这是波士顿大学建立网络研究中心的制度。