An Internet Multimedia Session Directory

1. Our Java implementation of a Session Directory. Information Discovery Graph • Design Features • Cache servers, called Managers, store session announcements • Managers auto-arrange in a hierarchy according to announcement content • Each manager handles a single semantic topic • Entities (people, software agents, etc.) can browse or search the hierarchy for content related to their interests. The architecture as seen from our simulation. Managers are purple. Data within the IDG is represented by light blue boxes. Lines represent the connections between multicast groups and the connections between data sources and managers. 1e+007 SAP (current architecture) Session Location Time IDG (our architecture) Session Location Time 1e+006 100000 10000 1000 100 10 1 10 100 1000 10000 100000 New! Info. Disc. Graph Comparison of time required to locate a session. The x-axis measures the number of sources available. The y-axis measures time in seconds to find relevant sources. Basketball Soccer Science Golf Sports Football WKMA Sport Safety College Football Go 49’ers News A new NFL team for LA? NFL ‘98 Politics Information Discovery Graph An Internet Multimedia Session Directory • What is a session directory? • The MBone is the portion of the Internet on which multicast is deployed - an efficient one-to-many broadcast mechanism. • Multimedia sessions are announced in a session directory, such as SDR, allowing users to locate and view interesting sessions. So, it is much like a TV Guide. • Announcements are made on a single multicast channel using the Session Announcement Protocol (SAP) to which users listen in order to receive session announcements. Current Session Directory Architecture - a single channel Announcement Traffic over Time Places Over the World (Continual Broadcast) CAIRN Research Mtg Monday, 10:00AM Ga Tech Multimedia Jukebox Places Over the World (Continual Broadcast) Announcements are repeatedly broadcast on a single address • Announcements are not cached within the network • Results in long start-up delays to hear all sessions • Announcements are not grouped or categorized by content • Unique Characteristics • Scalable design maintains fast searching as number of data sources grows • Information shared between managers ensures a robust environment in the case of failures • Taxonomy is flexible, allowing dynamic organization of new topics • Supports incremental deployment by encapsulating existing SDR traffic • Future Research • Develop spatial caching and other models to reduce global bandwidth (currently grows linearly with number of sessions) • Design better self-organizing behavior of managers • Complete transition from simulation to prototype UCLA Research Day The IDG architecture. All activities start at a well-known multicast address (WKMA). From there users can quickly reach managers holding topics in which they might be interested. Work done in collaboration with HRL Research Lab under DARPA ITO Intelligent Collaboration & Visualization Program (BAA 97-09). Nathan Sturtevant, Nelson Tang, Lixia Zhang {nathanst,tang,lixia}@cs.ucla.edu http://irl.cs.ucla.edu/IDG/