The focus of this paper is to design and develop a Peer-to-Peer Presentation System (P2P-PS) that supports E-learning through live media streaming coupled with a P2P shared whiteboard. The participants use the “ask doubt” feature to raise and resolve doubts during a session of ongoing presentation. The proposed P2P-PS system preserves causality between ask doubt and its resolution while disseminating them to all the participants. A buffered approach is employed to enhance the performance of P2P shared whiteboard, which may be used either in tandem with live media streaming or in standalone mode. The proposed system further extends P2P interactions on stored contents (files) built on top of a P2P file sharing and searching module with additional features. The added features allow the creation of mash-up presentations with annotations, posts, comments on audio, video, and PDF files as well as a discussion forum. We have implemented the P2P file sharing and searching system on the de Bruijn graph-based overlay for low latency. Extensive experiments were carried out on Emulab to validate the P2P-PS system using 200 physical nodes.

本文的重点是设计和开发一个点对点演示系统 (P2P-PS)，该系统通过实时媒体流和 P2P 共享白板支持电子学习。参与者使用“提出疑问”功能在正在进行的演示过程中提出和解决疑问。提议的 P2P-PS 系统在将问题传播给所有参与者的同时，保留了提出疑问与其解决方案之间的因果关系。采用缓冲方法来增强 P2P 共享白板的性能，它可以与实时媒体流结合使用，也可以在独立模式下使用。所提出的系统进一步扩展了 P2P 对存储内容（文件）的交互，该交互建立在具有附加功能的 P2P 文件共享和搜索模块之上。添加的功能允许创建带有注释、帖子、对音频、视频和 PDF 文件的评论以及论坛。我们在 de Bruijn 基于图的覆盖上实现了 P2P 文件共享和搜索系统，以实现低延迟。在 Emulab 上进行了广泛的实验，以验证使用 200 个物理节点的 P2P-PS 系统。