NeTS: Small: Toward All Videos on Demand

视频点播（VoD）是一种很有吸引力的服务，它允许用户在任何时候从一个大的目录中观看视频，已经在互联网上流行起来。现有VoD服务的一个局限性，无论是使用传统设计还是P2P，都无法以高质量的方式高效地流式访问所有内容，无论需求如何：不仅是数百万人想要看到的大片，而且还有与其非常受欢迎的同行相比需求相对较小的利基内容：电视节目的重播、非重磅发布、体育赛事的重播和演讲。对等（P2P）方法是可伸缩内容分发的有效解决方案，而不会对集中式基础设施造成重大负担。 在基于P2P的VoD系统中，用户从VoD服务器以及对等体接收流式视频。该项目扩展了成功的P2P视频点播系统的设计，以支持高效地交付一个大型的，潜在的无限的高质量（电影）存储的视频点播库。 不管视频的流行程度如何，高质量的版本都可以被任何连接到网络的客户端播放，而不会在请求后的几秒钟内中断。 本研究利用三个设计原则：对等技术、利他的跨内容缓存和服务、播放点加权缓存策略，得到了描述理想缓存行为的模型、实现理想缓存行为的分布式算法和功能原型。

Video-on-demand (VoD) is an attractive service that hasalready gained popularity in the Internet byallowing users to view a video from a large catalog atany time. A limitation of existing VoD services, bothusing traditional design as well as P2P is their inability to supportefficient streamed access to ALL content at high quality,regardless of demand: not just blockbusters that millions want tosee, but also niche content that has relatively small demand incomparison to their highly popular counterparts: re-runs of TV shows,non-blockbuster releases, replays of sporting events, and speeches.The peer-to-peer (P2P) approach is an effectivesolution for scalable content distribution without imposing asignificant burden on a centralized infrastructure. In a P2P-basedVoD system, users receive streamed videos from VoD servers as well asfrom the peers. The ability of peers that are viewing the videos tocollaborate with each other reduces the load on servinginfrastructure.This project extends the design of successful P2P VoD systems toenable support for efficient delivery of a large, potentiallylimitless library of high (movie) quality stored VoD. Regardless ofa video's popularity, a high-quality version will be playable by anyclient attached to the network without interruption within seconds ofits request. The research utilizes three design principles: leverageP2P technologies, implement altruistic cross-content caching andserving, and utilize playback-point weighted caching strategies.Results include models that describe desirable caching behavior,distributed algorithms to implement the desired caching behavior, anda functional prototype.