DVTSplus System Congxiao Bao CERNET, Tsinghua University 2011-5-19 - PDF document

DVTSplus System Congxiao Bao CERNET, Tsinghua University 2011-5-19 Outline • Background • System design • Summary and future work

DVTS applications on CERNET 2009 (1) (2) (3) •IASGO 2009, (2009.9) •28th APAN meeting live demo (2009.7) •CN, JP, TH Joint Workshop (2009.8) (4) (5) (6) •CN,JP,NO joint workshop (2009.10) •13th NSEAE (CN) (2009.11) CN,JP,HK workshop (2009.12) Start with those concepts… • Lighten the burden of rehearsals or the tests before formal event • Scalable system can accommodate more and more clients • Users want self service • Easy to use ……

To look back • First release – 2010.6 • First trial (version 0.3) – 2010.8 (30th APAN, VN) – 9 sites in Asia area • Second trial (version 1.0) – 2010.11 (2010 Fall Internet2 meeting) – 7 sites in Asia and North & South America • Third trail (version 1.3) – 2011.2 (31th APAN, HK) – 10 sites in Asia-pacific area 30th APAN

2010 Fall Internet2 member meeting 31th APAN

Many thanks to • Great technical supports from engineers of network and video/audio • Valuable comments, feedbacks and suggestions from doctors Architecture & building blocks (1) • Control path – Multiple operation modes • Chairman mode & Discussion mode – Compatibility • NTSC/PAL • Different network conditions

Architecture & building blocks (2) • Data path – DVclient • Send data to Transmitter and receive from Transmitter • Communicate with DVConfcenter – DVConfcenter • Communicate with DVClient • Send control message to Transmitter – Transmitter • Transmit the data • Consist of “channel”s – channel: one upstream and n downstream n ∈ [0 ， N] N = the count of attendees – Comparisons Quatre DVTS+ A B A B A B Chairman User control control A-D or A A-D MCU Transmitter B A B C C D D C D C D C D DVTS 30Mbps A MJPEG 1Mbps A

Main Technique design (1) • Multipoint-to-multipoint video with DVTS+ – Each site by DVclient • sends 1 DVTS video(720*480)(full-size video) • 1 MJPEG (180*120)video (small video) • 1 audio – Conference center • Receiving control signal from ordinary user and chairman – Transmitter • Controlled by conference center • No decoding for each DVTS video is required • 1 DVTS video and N received small videos by N sites are separately send to N sites (N+1 videos) Main Technique design (2) – Two basic operation modes • Discussion mode-DIY – The user decide which full-size video to watch – Talk freely – etc • Chairman control mode – Chairman decide which full-size video to watch for all users – Chairman help to sending only small videos for PAL user and limited network access user – Only chairman ‘s voice and one selected voice are in the channel – Queuing mechanism for talking

Main Technique design (3) – Switching between two basic operation mode in one session – Integrate self-test for network performance test and application system test in one system – Network performance monitoring during the session – Servers running 24 hours – As simple as web service Two operation modes – Two operation modes • Discussion mode (DIY) – The user decide which full-size video (main video) to watch – Talk freely – etc • Chairman mode – Chairman decides which full-size video to watch for all users – Only chairman ‘s voice and one selected voice are can be heard – Queuing mechanism for Q&A – These two operation modes can be switched in the same session

Recommended Operation modes • Using different operation mode for different Scenarios – Discussion meeting (<8sites) • Discussion mode only – Formal presentation meeting • Chairman mode + discussion mode • Switch between discussion mode and chairman mode controlled by chairman Fine tune video/audio • Independent audio channel – Disable original DVTS build-in audio – Not sensible to network congestion • Chairman can moderator the video/audio transmission – Keep the small video on and turn off the full-size one if the network condition of that site is not good – Keep the audio on only if the network bandwidth cannot support even the small video

Configuration • The source port number range can be limited which can provide better security control in the firewall • The locations of conference center and transmitter can be configured System login and join from web http://conf.dvtsplus.org

Summary • Multi-point system based on DVTS – Hardware appliances and configuration are the same as original DVTS – Download client and join the conference via website • 3 key features – Pre-test with the system at any time without partners – Free discussion mode + chairman mode • Small videos + standard DVTS video + audio – Distributed servers (mcu) Future plan • Support distributed servers with feature of load balancing • Support web based scheduling system • IPv6 support

Thank you