Vedantu recently presented at The Kranky Greek event. Here is the presentation emphasizing the use of webRTC technology in conducting LIVE online tutoring - The future of personalized education in India.

1. www.vedantu.com

2. Introduction

3. Marketplace of
Teachers

4. Growth
300
Hours in a Day
10000+
Hours in a Month

5. Live Classroom

6. Models

7. One to One - P2P
Signalling Server
(Node.js)
coTURN Server
Signalling
Whiteboard Data
Statistics
Recording
Signalling
Whiteboard Data
Statistics
Recording
MediaTeacher
StudentN
A
T
N
A
T

8. ❏ Requirements
❏ Session replay
❏ Academic Review
❏ Engagement analysis
❏ P2P WebRTC and recording
❏ Local storage of recordings
❏ Time to upload recordings
❏ Dependent on teacher & student to upload independent streams
❏ Huge size of recordings
❏ Convert audio to mp3 sampled at 8000 Hz
❏ Mobile CPU consumption to reduce audio upload size
Recording

9. Models

10. One to One & One to Few
Media Server
Media Server
Teacher
StudentStudent
Signalling Server MediaMedia
Media
One to Few:
P2P mesh not an option
Media Server
Central recording, Simulcast
Evaluation of Jitsi / 3rd party

11. Academic Quality
Verbal Interaction Whiteboard Usage Content Usage
- Conversation Analysis
- Tone Analysis
- Pace Analysis
- Space Usage
- Handwriting
- Activity
- Images and Shapes
- Annotations
Flagging, Reporting, Quality Control

12. Session Quality
[TBD] All statistics we collect - graphical
representation
★ Disconnects and Statistics
★ Support
★ Correlation with Engagement Analysis

13. WebRTC on Mobile
❏ Generate binaries for android using
depot tool
❏ Support x86, ARM architectures
❏ Increased app size by ~5 MB
❏ Average session duration 60 mins
❏ 300+ hours of live sessions in last 3
months
❏ Statistics (1 hr. session)
❏ 15-20% battery consumption
❏ 2-3 network disconnections

14. Statistics
Average Session Length 60 mins
TURN usage 24%
Disconnects / Session 1.46
Cloud telephony calls (bad networks) 5.3%
Initial connection establishment 1.7 sec
RTT 272 ms
Jitter 7 ms
Packet loss 0.08%

15. Issues
❏ Browser updates and compatibility
Firefox - Delay in permission popup
Firefox - BugID:852665 - Report WebRTC transport termination
❏ P2P - Session Recording
Remote stream recording API (recently available in Chrome 49)
Storage and Replay for P2P
❏ RTC Data connection cannot be used for Whiteboard data
Firefox issue - ICE state changes not detected
Application level keep-alive (ping pong) for detecting connection state
Issue with reconnect and performance

16. Look forward to
❏ VP9 and all its goodness
❏ Call summary
❏ Quality - MOS, PESQ score
❏ Jitter
❏ Packet loss
❏ RTT
❏ Bandwidth
❏ Duration
❏ API for bandwidth limiting instead of SDP munging

17. Journey ahead
❏ Build the Knowledge sharing
network
❏ Connect at scale
❏ Truly democratize education

18. THANK YOU