Portlets and Web Services for Collaboration and Videoconferencing

1. NESC 16 July 2003 Portlets and Web Services for Collaboration and Videoconferencing PTLIU Laboratory for Community Grids Geoffrey Fox, Hasan Bulut, Bryan Carpenter, Marlon Pierce, X. Qiu, Ahmet Uyar, Wenjun Wu Indiana University, Bloomington IN 47404 gcf@indiana.edu

2. Abstract • We define interoperable framework called XGSP (XML based General Session Protocol) based on Web services technology for creating and controlling sessions • We developed a common dynamic messaging environment (NaradaBrokering) for Grid and collaboration applications • Based on the web-services framework and NaradaBrokering messaging environment, we are developing Global Multimedia Collaboration System (Global-MMCS) with Beihang University China • We use MVC (Model View Control) paradigm to develop Web Service model/data – Messaging Control -- Jetspeed style aggregation – portlet style view

3. Collaboration and Web Services • Collaboration has • Mechanism to set up members (people, devices) of a “collaborative sessions” • Shared generic tools such as text chat, white boards, audio-video conferencing • Shared applications such as Web Pages, PowerPoint, Visualization, maps, (medical) instruments …. • b) and c) are “just shared objects” where objects could be Web Services but rarely are at moment • We can port objects to Web Services and build a general approach for making Web services collaborative • a) is a “Service” which is set up in many different ways (H323 SIP JXTA are standards supported by multiple implementations) – we should make it a WS

4. Shared Event Collaboration • All collaboration is about sharing events defining state changes • Audio/Video conferencing shares events specifying in compressed form audio or video • Shared display shares events corresponding to change in pixels of a frame buffer • Instant Messengers share updates to text message streams • Microsoft events for shared PowerPoint (file replicated between clients) as in Access Grid • Finite State Change NOT Finite State Machine architecture • Using Web services allows one to expose updates of all kinds as messages • “Event service” for collaboration is similar to Grid notification service and we effectively define SDE’s (service data elements) in OGSI • Group (Session) communication service is needed for the delivery of the update events • Using Event Messaging middleware makes messaging universal

5. Portals and Web Services • Web Services allow us to build a component model for resources. • Each resource naturally has a user interface (which might be customized for user) • Web Service <--> Portlet • Natural to use a component model for portal building displayed web page from collection of portlets • So can customize each portlet and customize which portlets you want • Need to redirect portlets to cell-phones etc. • What is form of MVC (Model-View-Controller) paradigm • What happens if “real applications” like PowerPoint are formulated as Web Services • Jetspeed uses HTML to build a portal – as well as Java, SVG (Scalable Vector Graphics) is interesting

6. Session Server XGSP-based Control Media Servers Filters NaradaBrokering All Messaging Admire SIP H323 Access Grid Native XGSP XGSP MCU Architecture Use Multiple Media servers to scale to many codecs and many versions of audio/video mixing WebServices NB Scales asdistributed High Performance (RTP)and XML/SOAP and .. Gateways convert to uniform XGSP Messaging

7. Global-MMCS 2.0 (1) XGSP MCU • We are building an open source protocol independent Web Service “MCU” which will scale to an arbitrary number of users and provide integrated thousands of simultaneous users collaboration services. • We will deploy it globally and hope to test with later this year. • The function of A/V media server will be distributed using NaradaBrokering architecture. • Media Servers mix and convert A/V streams • Open XGSP MCU based on the following open source projects • openh323 is basis of H323 Gateway • NIST SIP stack is basis of SIP Gateway • NaradaBrokering is open source messaging from Indiana • Java Media Framework basis of Media Servers

8. Shared Output Port Collaboration WSDL R U Application orContent source F F WSViewer WSDisplay I I O O Web Service Collaboration as a WSSet up Session with XGSP Web Service Message Interceptor Master WS Viewer WS Display Text Chat Whiteboard Multiple masters Event(Message)Service OtherParticipants WS Viewer WSDisplay

9. R R R U U U WSViewer WSDisplay F F F F F F I I I I I I WebService WebService WebService O O O O O O WS Viewer WS Display WS Viewer WSDisplay Shared Input Port (Replicated WS) Collaboration Collaboration as a WSSet up Session with XGSP Master Event(Message)Service OtherParticipants

10. XGSP Conference Control Framework Components • User session management • User session management supports user sign-in, user create/terminate/join/leave/invite-into XGSP sessions. • Application Session Management • XGSP application session management provides the services to A/V and data application endpoints and communities, controlling multipoint A/V RTP and data channels. • Floor Control • Floor control manages the access to shared collaboration resources.

11. XGSP Application Session Management • XGSP signaling protocol for • H.323 signaling protocols (H.225, H.245) • SIP signaling protocol ( Invite, Bye Message ) • Access Grid ( Unicast VIC & RAT ) Join XGSP Session, Leave XGSP Session, Invite into XGSP Session, Expel from XGSP Session • Activate the XGSP session • the XGSP session server will link all the “rooms” in the session together by connecting multipoint A/V and data channels from different communities to the XGSP A/V Media and Data Channel Services. Link/Disconnect XGSP SubSession

12. XGSP Floor Control • XGSP should provide: • Floor control primitives, including: request floor, release floor, grant floor, cancel floor, remove floor request • mediator-controlled floor control: to support the mediator control policy • Collaboration applications have to define their own roles in the XGSP registration so that the mediator could assign the role of the application to each user. for example, a shared PowerPoint application should define master/slave role.

13. NaradaBrokering • Based on a network of cooperating broker nodes • Cluster based architecture allows system to scale to arbitrary size • Originally designed to provide uniform software multicast to support real-time collaboration linked to publish-subscribe for asynchronous systems. • Now has five major core functions • Message transport (based on performance measurement) in heterogeneous multi-link fashion • General publish-subscribe including JMS & JXTA and support for RTP-based audio/video conferencing • Distributed XML data-base using P/S XPATH metaphor • Filtering for heterogeneous clients • Federation of multiple instances of Grid services as illustrated by JXTA peer-group linkage

14. vic and RealVideo views of multiple streams

15. Polycom view of multiple video streams

16. Performance Test : GlobalMMCS1.0 • We conducted extensive performance tests on audio and video servers. • Video: • The test shows that our video server is capable of supporting 300 clients if there is only one video sender. • Video Server Machine : 1.2GHz Intel Pentium III dual CPU, 1GB MEM, RedHat Linux 7.3 • Audio: • Our tests show that audio server can support 5 concurrent sessions (250 participants in total) without any packet droppings. • Audio Server Machine:2.5GHz Pentium 4 CPU, 512MB memory, Windows XP machine • Scale with logarithmic Broker network

17. Sender/receiver/broker - (Pentium-3, 1 GHz, 256 MB RAM). 100 Mbps LAN. JDK-1.3, Red Hat Linux 7.3

19. Comparison between the performance of NaradaBrokering and JMF

20. Comparison between the performance of NaradaBrokering and JMF

21. Global-MMCS 2.0 (2) Portlets • Collaboration clients will be built into portlets by creating Java Applet or ActiveX controls for the non-HTML clients and adding them into HTML pages. • A collaboration portlet opens local services for XGSP application session management and floor control. • Node Manager portlet invoke the service to control local portlets • Apache Jetspeed seems good open source technology supporting this model • Portlets such as Access Grid portlet (really a VIC portlet) can be reused by Grid Portal Developers

22. Unicast AG Portlet

23. Multicast Multi-stream AG Portlet • Java applet supports multicast AG with multiple streams • In Jetspeed, easiest to have fixed size but this doesn’t fit well natural range of 1-20 separate streams

24. Collaborative SVG Web Service • SVG is W3C 2D Vector Graphics standard and is interesting for visualization and as a simple PowerPoint like application • Further SVG is built on W3C DOM and one can generalize results to all W3C DOM-based applications (“all” in future?) • Apache Batik SVG is Java and open source and so it is practical to modify it to explore • Real Applications as a Web Service • Collaboration as a Web Service • MVC model and web services with implications for portlets • We intend to use NaradaBrokering and XGSP to control collaboration; support PDA Cell-phone and desktop clients; restructure Batik as MVC Web Service • Good progress in all areas see • http://www.svgarena.org for SVG Games • http://grids.ucs.indiana.edu/ptliupages/projects/carousel/ for PDA

25. Collaborative SVG Chess Game in Batik Browser Players Observers

26. Architecture of collaborative SVG browser on PC

27. Classic MVC Paradigm

28. Reformulation of SVG to message based MVC in a Web Service Model

29. Architecture of multiplayer game with SVG Web Services Messaging Displays

30. Collaborative SVG As A Web Service

31. Three among the different ways of decomposing SVG between client and Web Service component

32. Real-time Community Collaboration Scalable Vector Graphics (SVG) via “Shared Web Service”