R Review of DVTSplus System i f DVTS l S t Congxiao Bao CERNET - - PowerPoint PPT Presentation

R i f DVTS l S t Review of DVTSplus System

Congxiao Bao CERNET T i h U i it CERNET, Tsinghua University 2011-8-24

Participants Today Participants Today

1 M i V i D lhi

• 1.Main Venue in Delhi
• 2. Nation TaiWan University hospital ,Taipei ,(NTU)
• 3 National Center for High
• 3. National Center for High-

performance Computing (NCHC), Taiwan (NCHC)

• 4.Kyushu University Hospital, Fukuoka, Japan (KUH)

4.Kyushu University Hospital, Fukuoka, Japan (KUH)

• 5.Masaryk Hospital, Usti, Czech (MNUL)
• 6.CESNET HQ, Prague, Czech (CHQ )

, g , ( )

• 7.University of Malaya, Malaysia (UOM )
• 8.Asian Institute of Gastroenterology, Hyderabad, India

(AIG)

• 9. Tsinghua Univeristy Beijing ,China (THU)

Outline Outline

• System description
• Past experiences

Past experiences

• Statistics analysis from past usage
• Summary and future work

What is DVTSplus What is DVTSplus

• Extension of DVTS system for multi-sites

communication

– Keep DVTS video/audio quality More flexible management dealing with – More flexible management dealing with network sensitivity, time-consuming testing, t ti h d li d li it ti f b automatic scheduling and limitation of number

• f participants

Look in deep Look in deep

M li t di t ib t d ( k t th

• Many clients, distributed servers (work together as a

whole MCU)

• No decoding, just forwarding

g, j g

• Standard DVTS video/audio, combined with small

video/audio, represented by different channels Different application scenarios determine different

• Different application scenarios determine different

signaling

• Signaling system determine which channel to forwarding

g g y g

• Two basic modes include Chairman mode and discussion

mode

• The number of participants are limited by hardware
• The number of participants are limited by hardware

configurations (CPU/memory/bandwidth of Ethernet card etc.)

From user’s operation From user s operation

• Same local hardware setup as WIDE

DVTS

• Web-based to access the system

http://conf dvtsplus org http://conf.dvtsplus.org

• Just “click” on the website to achieve your
• wn control in discussion mode

To look back To look back

First release

• First release

– 2010.6

• First trial (version 0.3)

First trial (version 0.3) – 2010.8 (30th APAN, VN)

– 9 sites in Asia area

S d t i l ( i 1 0)

• 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 – 10 sites in Asia-pacific area

• Forth trial (TERENA 2011, Prague)

– 14 Sites in Asia-pacific and Europe

30th APAN 30th APAN

2010 Fall Internet2 member meeting 2010 Fall Internet2 member meeting

31th APAN 31th APAN

TNC2011 TNC2011

Many thanks to Many thanks to

• Great technical supports from engineers of

network and video/audio in each station

• Valuable comments, feedbacks and

suggestions from doctors as well suggestions from doctors as well

what’s what s

• What you saw in past demo
• What are the reasons behind

What are the reasons behind

• What we have done since then

First trial First trial

• In the demo

– One site with blinking small video (no large g ( g

• ne) and much noises, made the general

feeling in the main venue was not good g g – One site had to adjust the sound volume from time to time to get acceptable quality time to time to get acceptable quality – Chairman in the venue had some trouble in finding who will be the next questioner during finding who will be the next questioner during the Q&A

First trial First trial

R b hi d

• Reasons behind

– Local network problems, the whole system could not be able to do anything to improve – Not so skillful on system adjustment, the whole system didn’t provide echo cancellation functions, the quality of voice largely depends th l l i ' kill

• n the local engineer's skills

– Many participants shown in the many small id diffi lt t b i d t h t videos, difficult to be recognized at very short time

Second trial Second trial

• In the demo

– Echo still can be found even the local engineer is skillful – The Voice quality from the standard DVTS The Voice quality from the standard DVTS can be affected by a very small packet loss

Second trial Second trial

• Reasons behind

– Still no professional echo-cancellation p function in the system – Standard DVTS have video&voice build-in Standard DVTS have video&voice build in together

N i t

• New requirements

– HD – Distributed server

Third trial Third trial

• In the demo

– Almost perfect p

• More new requirements

R di – Recoding – Separate screens

Fourth trial Fourth trial

• In the demo

– Unstable video quality between Beijing and q y j g Prague when enable a server in Prague – Small videos can not be seen all the time so Small videos can not be seen all the time, so the operator is “blind”

• ne stations can not hear Beijing’s voice

– one stations can not hear Beijing s voice – Discontinuous voice between Beijing and P ? Prague?

Fourth trial Fourth trial

• Reasons behind

– Jitter and packet loss in Beijing-Europe link p j g p – The resolution in the Prague venue is very low (600*800) low (600 800) – Maybe Some problem in local PC (not completely locate) completely locate)

(1) (2) (3) (4) (5) (6) (7)

What we have done What we have done

Si 1 t t i l

• Since 1st trial

– Online testing server running 24 hours in a separate session session – Create chairman mode besides discussion mode – Chairman can moderator the video/audio t i i transmission – Audio control to avoid echo

• Only chairman ‘s voice and one selected voice are in the

y channel

– Queuing mechanism for questioner Distributed server without load balancing – Distributed server without load balancing – Configurable for firewall settings – Network conditions monitoring – Web-based scheduling system

Network condition monitoring Network condition monitoring

In the plan In the plan

• Echo-cancellation
• Load balancing for distributed server

Load balancing for distributed server

• HD
• IPv6 support

Thank you y