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) (4) (5) (6)

• 28th APAN meeting live demo (2009.7)
• CN, JP, TH Joint Workshop (2009.8)
• IASGO 2009, (2009.9)
• 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

A

A

MCU B C D A-D

A B C D

• r

A A B C D

A B C D A B C D

A-D Transmitter DVTS 30Mbps MJPEG 1Mbps Quatre DVTS+

Chairman control User control

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