Video Conferencing with NaradaBrokering
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Video Conferencing with NaradaBrokering

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  • 1. Video Conferencing with NaradaBrokering Mark Baker and Rahim Lakhoo QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.
  • 2. Outline • Introduction • Motivation • Technologies: – GridSphere, – Java Media Framework, – NaradaBrokering. • System Architecture • Experiments • Issues • Conclusions 13 July 2006 2
  • 3. Introduction • Portsmouth and Reading’s role in the Sakai VRE project is to develop and deploy a number of portlet-based tools and services. • In particular we are looking at: – Collaborative tools based on NaradaBrokering, – Semantic Web tools based on RDF, – Bridging technologies to enable legacy applications, – Peer-to-Peer technologies. • Portsmouth and Reading are developing JSR-168 portlets, on the basis that Sakai will consume portlets via the WSRP consumer developed within the project. • In this talk we will recount our experiences developing, deploying and testing chat and video conferencing services based on NaradaBrokering, 13 July 2006 GridSphere and the Java Media Framework. 3
  • 4. Collaborative Service • Motivation: – Investigate NaradaBrokering that is also partially funded by the e-Science programme, which other UK Universities and organisations are interested. – Add useful tools for the Sakai Demonstrator, – To create a chat and video conferencing system that work-site users and external users may communicate with. – To provide the ability to conference with many participants, i.e. meetings or teleconferences. – Note: this work was completed in Jan 2005. 13 July 2006 4
  • 5. Technologies Choices • GridShpere: – Supports JSR-168 and WebSphere portlets, – Provides a portal framework, not just a portal, but a development infrastructure. – Has an active support and user community. • NaradaBrokering: – Unified messaging framework with support for Grid and Web Services, – Software multi-casting with support for different transport protocols, – Supports video conferencing with Global-MMCS. • Java Media Framework: – Java-based solution for handling time-sensitive data, – Ability to capture video and compress streams in different formats, – Supports the Real-Time Protocol. 13 July 2006 5
  • 6. Portals - GridSphere • The GridSphere framework provides an open-source portlet-based Web portal. • The framework allows developers to manage and deploy portlets within the container. • GridSphere supports JSR-168 and WebSphere-based portlets. • GridSphere also supports GridPortlets for managing jobs and data on the Grid. • GridSphere uses Apache Tomcat as its container – though it can also use Jetty. 13 July 2006 6
  • 7. Java Media Framework (JMF) • JMF provides an interface for Java applications to interact with media or time sensitive data. • JMF includes codecs and protocols, such as: – Support for Quick Time movies, – MP3 playback, – Video/audio capture, – Supports the Real Time Protocol (RTP), – H.263 video conferencing codec (compression format). • JMF is available in two formats: – Performance Pack, for only Linux, Solaris and Windows: • Includes native libraries for codecs and capturing from devices, – Platform Independent version: • Includes partial capability for codecs and no video capturing. 13 July 2006 7
  • 8. NaradaBrokering • NaradaBrokering is developed by the Community Grids Lab at Indiana University. • Originally designed to provide software multi-casting for real-time collaborative systems. • Asynchronous messaging system that is JMS 1.02b compliant. • Publish, subscribe and bind architecture with JMS topics. • NaradaBrokering supports other capabilities: – Video Conferencing via Global-MMCS, – Peer-to-Peer with JXTA, – Grid and Web Services. • Provides a number of transport protocols: – HTTP/HTTPS, TCP/NIO-TCP and UDP. 13 July 2006 8
  • 9. NB Chat and Video Architecture • The NB Chat and Video System consists of portlets, portlet services and Java applets from a users perspective: – Chat portlet, – Video Conferencing portlet, – NaradaBrokering portlet service, – Userlist portlet service, – JMF applet. • The servers consist of: – NaradaBrokering, – Apache Tomcat, – GridSphere, – Global-MMCS. 13 July 2006 9
  • 10. System Architecture 13 July 2006 10
  • 11. The Chat Service (1) • The Chat Service consists of: – A Chat portlet, – A NaradaBrokering portlet service, – A Userlist portlet service. • The Chat portlet provides the interface and user notification messages. • The NaradaBrokering portlet service, handles all connections and messages to be sent/received for all connected users. • The Userlist portlet service tracks connected users and stores user information. 13 July 2006 11
  • 12. The Chat Service (2) The User Interface 13 July 2006 12
  • 13. The Chat Service (3) Configuration Interface 13 July 2006 13
  • 14. An Example System Set-up N a ra d a B r o k e r in g , B r o k e r c lo u d P o r tle t S e s s io n B ro k e r S e rv e r J M S T o p ic C o n n e c tio n O b je c t J M S P u b lis h e rs S e s s io n O b je c t J M S S u b s c r ib e r S e s s io n O b je c t N a ra d a B r o k e r J M S T o p ic P u b lis h er O b je c t J M S T o p ic S u b s c r ib e r O b je c t C h at T o p ic N JM S T o p ic U s e r n a m e J M S T o p ic S tr in g J M S C o n n e c tio n P ro p e r tie s J M S T e x t M e s s a g e s R e c e iv e d J M S T e x t M e s s a g es t o S e n d T om c at C o n n e c tio n S ta t u s C o n ta in e r G r id s p h e r e S e s s io n S e s s io n in fo - 3 in fo - 2 N a r a d a B ro k e r in g S e r v ic e S e s s io n S e s s io n in fo - 4 in fo - 1 C hat V id e o C h at V id e o C lie n t 1 C h at V id e o C lie n t 4 C hat V id e o 13 July 2006 C lie n t 3 14 C lie n t 2
  • 15. The Chat Service (4) • Each user has a PortletSession, which hold all connection information per a user. • The Chat portlet and the NaradaBrokering portlet service use PortletSessions for the communication of messages and connection information. • Messages are sent by the NaradaBrokering portlet service to a JMS Chat topic on the broker. • Each user has an associated asynchronous MesaageListener, which stores any received messages inside their PortletSession. 13 July 2006 15
  • 16. The Video Service (1) • The Video Service consists of: – A Video Conferencing portlet, – JMF Applets, – A Userlist portlet service. • The Video Conferencing portlet displays a list of available cameras and loads the relevant JMF applet. • The Userlist portlet provides the video stream topics and other details, to initiate the video conference. 13 July 2006 16
  • 17. The Video Service (2) The Video Camera Subscription Interface 13 July 2006 17
  • 18. The Video Service (3) • Users may publish a web-cam or subscribe to other registered web-cams. • The video conferencing portlet gathers user information from the Userlist portlet service, to display a list of any available cameras. • The video conferencing portlet generates an applet tag with the connection details. • The applet then connects to a broker to initialise a video conference. 13 July 2006 18
  • 19. Video Service (4) • There are two JMF applets: – A transmitting applet which captures a device, – A receiving applet which displays a video stream. • The transmitting applet captures a users Web-cam as RTP data and encapsulates it within the NaradaRTPConnector. • The receiving applet uses the NaradaRTPConnector to extract the video stream and plays it with a JMF player. • This means that only one UDP port is required to be open on the broker for users to use the video conferencing. • The chat facility also only requires one TCP port on the broker. • This is unlike VRVS or Access Grid which requires a range of ports to be open. 13 July 2006 19
  • 20. Chat and Video Services • The presentation layers are separated from the logic – an MVC design pattern. • All inter-portlet communications are undertaken with either PortletSessions or via portlet services. • The portlet services interact with external sources, while the portlets only deal with the layout and passing of information to the services. 13 July 2006 20
  • 21. NB Chat and Video System Experiment • The Chat and Video Portlet was tested with four cameras and five users. • Each participant was connected to the chat room and four cameras where published. • All participants subscribed to all four cameras. • To stress test the system all participants subscribed multiple times to all four cameras. • The limitations of the number of subscriptions each user could make, was only limited by their system resources. • The maximum obtained was 18 subscriptions with one published camera, by a single user. • The broker and GridSphere consistently utilised 500 MBytes of memory, peaking to 643 MBytes. 13 July 2006 21
  • 22. NB Chat and Video System Experiment 13 July 2006 22
  • 23. Issues • The RTPLinkManager in NaradaBrokering (0.99RC4) has ‘hardwired’ ports, even though there is a configuration file. • NaradaBrokering’s RTP session configuration file is not dynamic; it requires a broker restart. • When many messages are sent to the broker memory usage increases and eventually the broker fails. • The system suffers from session bloating with this portlet and thus consumes a lot of memory. • Memory is not reclaimed by the system. • JMF has compatibility issues with web-cams and Linux. • Refreshing the chat room messages automatically requires other technologies, such as AJAX and/or JavaScript. • Closing the an applet’s connection is problematic; needs the whole browser to be shutdown. 13 July 2006 23
  • 24. Conclusions • As proof of concept the system does work, however, some of the technologies and standards need to mature. • Installing JMF is still problematic for platforms other than Windows and seems to be a dormant project, with few updates. • JSR-168 does not accommodate for the concept of portlet services, thus portlets could be very large and not easily reusable. • NaradaBrokering’s RTP support and JMS API needs to be extended to improve its capabilities. 13 July 2006 24
  • 25. References • http://www.gridpshere.org • http://www.naradabrokering.org • http://java.sun.com/products/java-media/jmf/ • http://www.globalmmcs.org/ • http://java.sun.com/products/java- media/jmf/2.1.1/guide/JMFArchitecture.html • http://www.javaworld.com/javaworld/jw-08- 2003/jw-0801-portlet.html • http://www- 128.ibm.com/developerworks/websphere/library /techarticles/0312_hepper/hepper.html 13 July 2006 25
  • 26. Questions? http://dsg.port.ac.uk http://acet.rdg.ac.uk QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.