1. Portlets and Web Services for Collaboration and Videoconferencing
NESC 16 July 2003
PTLIU Laboratory for Community Grids
Geoffrey Fox, Hasan Bulut, Bryan Carpenter,
Marlon Pierce, X. Qiu, Ahmet Uyar, Wenjun Wu
Indiana University, Bloomington IN 47404
2018/11/28

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
2018/11/28

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
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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
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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
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6. XGSP MCU Architecture
Use Multiple Media servers to scale to many codecs and many
versions of audio/video mixing
Media Servers
Filters
Session Server
XGSP-based Control
NaradaBrokering
All Messaging
Web Services
NB Scales as distributed
High Performance (RTP) and XML/SOAP and ..
SIP
H323
Access Grid
Native XGSP
Admire
Gateways convert to uniform XGSP Messaging
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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
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8. Event (Message) Service
Shared Output Port Collaboration
Collaboration as a WS Set up Session with XGSP
Web Service Message
Interceptor
Master
Application or Content source
WSDL
Web Service F I U O R
WS Display
WS Viewer
WS Viewer
WS Display
Text Chat
Whiteboard
Multiple
masters
Event (Message) Service
Other Participants
WS Viewer
WS Display
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9. Event (Message) Service
Shared Input Port (Replicated WS) Collaboration
Collaboration as a WS Set up Session with XGSP
Web Service F I U O R
WS Display
WS Viewer
Master
Web Service F I U O R
WS Display
WS Viewer
Event (Message) Service
Other Participants
Web Service F I U O R
WS Display
WS Viewer
2018/11/28

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.
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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
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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.
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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
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14. vic and RealVideo views of multiple streams
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15. Polycom view of multiple video streams
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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
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17. Sender/receiver/broker - (Pentium-3, 1 GHz, 256 MB RAM). 100 Mbps LAN
Sender/receiver/broker - (Pentium-3, 1 GHz, 256 MB RAM). 100 Mbps LAN. JDK-1.3, Red Hat Linux 7.3
2018/11/28

18. 2018/11/28

19. Comparison between the performance of NaradaBrokering and JMF
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20. Comparison between the performance of NaradaBrokering and JMF
2018/11/28

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
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22. Unicast AG Portlet
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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
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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
for SVG Games
for PDA
2018/11/28

25. Collaborative SVG Chess Game in Batik Browser
Players
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Observers

26. Architecture of collaborative SVG browser on PC
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Architecture of collaborative SVG browser on PC

27. Classic MVC Paradigm
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28. Reformulation of SVG to message based MVC in a Web Service Model
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29. Architecture of multiplayer game with SVG
Web Services Messaging Displays
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30. Collaborative SVG As A Web Service
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31. Three among the different ways of decomposing SVG between client and Web Service component
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32. Real-time Community Collaboration
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Scalable Vector Graphics (SVG) via “Shared Web Service”