The mStar environment : scalable distributed teamwork using IP multicast

Abstract: This thesis addresses the question of how a scalable, distributed teamwork environment should be designed and realized. Central design criteria includes that the system should be scalable and robust, allow for easy access and be symmetric. The system should allow for project team members to collaborate even though they are not located at the same physical location. The resulting system presented in this thesis, called the mStar environment have been created to address exactly these questions. mStar is scalable and robust through the usage of standard networks and IP-multicast, it allows for easy access as it is desktop based and finally it is symmetric allowing for easy peer-communication. mStar includes support for desktop conferencing, including mAudio for audio, reuse of the MBone Vic tool for video, mWB for whiteboard, mChat for text based chat and mVote for voting. It also supports distributed synchronized presentations using the WWW and the mWeb application. As all traffic is network and IP-multicast based it allows for easy recording and playback of teamwork sessions using the mMOD application. To allow for easy access to users behind non-multicast capable network segments (primarily modem and ISDN), mTunnel was created. It allows for tunneling and transformation of the traffic. Another member of the mStar environment is Director for remote control of video equipment. mStar also includes support for easy creation of new teamwork tools and applications using the Tunable Multicast Platform - /TMP and the Generic Agent Architecture. The mStar environment can be used and is being used on a daily basis for electronic meetings, distance education and lectures, and daily teamwork. The usage mStar creates group awareness between project members and helps users from not becoming isolated from their department and project team. mStar allows for usage 24 hours a day and have resulted in, among other things, a new usage patterns, which resembles electronic corridors more than specific meetings, where users can and do meet spontaneously to talk about anything they want, but also overhear other interesting and important conversations just as in a physical office corridor.