1. D. Sturzebecher, Institute of Operating Systems and Computer Networks, TU-Braunschweig MACS (multicast-based advanced collaboration system) A flexible and scalable collaborative environment O.Brand, W.Mahalek, D.Sturzebecher, M.Zitterbart Institute of Operating Systems and Computer Networks Technical University Braunschweig Outline Motivation Structure GUI Status and next steps Copyright 1998. Association for the Advancement of Computing in Education (AACE). Distributed via the Web by permission of AACE.

2. D. Sturzebecher, Institute of Operating Systems and Computer Networks, TU-Braunschweig Motivation n Shortcomings in current systems Lacking control (e.g. MBone) Insufficient control (e.g. NetMeeting) Strongly limited scalability (ITU-T.120 based systems) Virtual reality based control (e.g. MASSIVE) Goals n Flexible and scalable collaborative environment n Ease of use Advanced GUI Enhanced floor-passing mechanisms n Extensible / no assumptions about content n Portable (Java based) n Interworking with MBone, T.120 and the like No moderated conferences first come first serve too many windows No moderated conferences first come first serve too many windows Too complicated Framework Beispiel TelSEE

3. D. Sturzebecher, Institute of Operating Systems and Computer Networks, TU-Braunschweig Structure of MACS-framework n 4 horizontal layers n Variable number of applications LRMP (Reliable Multicast) Video WB Audio TelSEE Control (incl. ViSCO) TelSEE- Window WB- Window Video- Window TelSEE Panel Control-Window Video- Panel Control Panel Display Control ApplicationsSessions Tools Network Audio Panel Network Glue ViSCO TCP UDPCORBA Floor-Strategies Floor-Mechanisms Control-Interface

4. D. Sturzebecher, Institute of Operating Systems and Computer Networks, TU-Braunschweig Structure of MACS-applications n MACS-application Java package Implements MacsApplication interface Calls directly Control methods n Application loading Name of class in properties file Load class Check interface implementation (Version check) Create instance Initialise Start

5. D. Sturzebecher, Institute of Operating Systems and Computer Networks, TU-Braunschweig Graphical User Interface n MACS-Session with ViSCO (visual session and floor control) user iconabsent useruser picturecamera iconapplication areachat application

6. D. Sturzebecher, Institute of Operating Systems and Computer Networks, TU-Braunschweig Status and next steps n Current status Whiteboard used for tele-teaching (second demo-release) Preparation of first demo-release of MACS including: –ViSCO (for discussions and meetings) –Whiteboard –TelSEE (CASE) –Basic conferencing tools (audio, video and chat) n Next steps Different scenarios Signalling & control MACS and QoS n Further info MACS: http://www.ibr.cs.tu-bs.de/projects/macs/ Whiteboard: http://www.ibr.cs.tu-bs.de/projects/macs/doc/whiteboard/ Hierarchies Interworking Mapping of scenarios to QoS