WebRTC STRATEGIES. Video Chat Issues. Session: D1-5 Richard Tworek Principal WebRTC Strategies

Transcription

1 WebRTC TRATEGIE Video Chat Issues ession: D1-5 Richard Tworek Principal WebRTC trategies

2 ession Presenters Gustavo Garcia Bernardo Cloud Architect TokBox Philippe ultan Title R3Load Dr Alex Gouaillard CTO Temasys Michael Trank Product Manager Apex Voice

3 Gustavo García Cloud Architect

4 What are our customers demanding Best possible audio quality even on noisy environments or under low bandwidth Adaptation to heterogeneous devices and different network conditions Archiving solution for recording and playback Integration of legacy endpoints and networks Dynamic and flexible layouts Large scale distribution for broadcast-like events

5 What solutions are we using today Full Mesh uper Peer MCU/Mixer Router/Relay MCU Router

6 What else do we need to make it real Improved audio processing and coding Advanced and more flexible congestion and bitrate control imulcast and layered video coding capabilities

7 Flexibility Quality Cost The goal is connectivity, the tool is the Internet Protocol, and the intelligence is end to end rather than hidden in the network. Architectural Principles of the Internet (RFC1958)

8 Philippe ultan CTO R3Load

9 Who we are We re a VoIP carrier that offers an API Get a IP domain, phone numbers Write code on your server using our RET / XML API And write Javacript for WebRTC applications that Allows connections to the PTN (e.g. Real click-to-call) Use our MCU for multi conferencing

10 Why we chose an MCU? We use opensource telecom softwares Asterisk, FreeWITCH, Kamailio Asterisk and FreeWITCH already have good audio MCU engines embedded Audio mixing on the fly Bridging WebRTC and the PTN is easy Lesser known but nice : Licode by Lynckia Okay, can t we just use that to relay streams to/from WebRTC endpoints?

11 Issues with video You can t mix video like you mix audio Need to distinguish between video sources At the network level By using multiple UDP sockets for RTP By using multiple RCs over a single UDP socket for RTP By decoding/encoding the video frames on the MCU

12 Options to relay the video Multiple PeerConnections A single PeerConnection with multiple video Mediatreams? A single PeerConnection/Mediatream with multiple videotracks? A single PeerConnection/Mediatream/videoTrack? Needs decoding/encoding on the MCU FFmpeg?

13 Need to adapt the code Asterisk ICE, RTP, DP included A good candidate to be a PeerConnection Developed our own signalling channel (raw JON actually) chan_websocket.so Push events to the WebRTC endpoints Join/leave events Text messages Who s talking events

14 Dr. Alex Gouaillard, CTO Temasys

15 Extension of reference code: p2p, a.k.a Mesh - Limits of pure meshes Alice Bob 2 Bob Alice Chris Bob 6 Alice Chris 20 Dave Ed Alice Bob Chris David 12 n(n-1) O(n^2)

16 Extension of reference code: p2p, a.k.a Mesh - Limits of pure meshes More streams = more bandwidth but the real bottleneck is the CPU today - VP8 hardware support - Tegra2 / nexus, yes but no.. - Tegra 3? - Others - Bandwidth opt implementation (2,000k per stream really?) - Constraint - B=A:<> - Encoder/decoder params? orry, no API. Bottom line: 9 people on this macbook air. How many with GPU support? Mobile needs love, but also need GPU support (well, mostly GPU )

17 Business as usual MCU: multiplexing streams - wow, super bandwidth! - Hum, what about latency? - What happen if peers are far away.? Bob Alice MCU Chris 5 Dave Ed n O(n)

18 Business as usual MCU: multiplexing streams - Interface layout?? - CP, VA - Ok, that s great but. - Chat? I mean, if only to pass a link - Collaboration (white board?) - ervices other than A/V? - Usage beyond the boardroom model: BYOD device, work from home,.

19 marter topology? - bandwidth optimization WITH layout freedom Bob type treams IN treams OUT p2p N-1 N-1 MCU 1 1 Alice Multi cast Chris 12,5 Hybri d N-1 1 Dave Ed (n^2)/2 O(n^2)

20 marter topology? - bandwidth optimization WITH layout freedom type treams IN treams OUT p2p N-1 N-1 MCU Hybri d N

21 Broadcast / seminar - group chat, but one way, and latency not a problem - can webrtc relay today..? - can we send a video file through a PC? Multi cast Multi cast Prof Multi cast Multi cast Multi cast

22 Michael Trank Product Manager Apex Voice

23 WebRTC changes traditional web traffic patterns Digital bandwith utilization has grown less assymetric with new multimedia services. WebRTC Video streams are bandwidth hogs. VGA: Mbps 720p: Mbps Good user experiences will require availability of high capacity subscriber lines.

24 Users will mostly access WebRTC services through Fiber to the Node (FTTN) ubscriber Lines ubscriber line last mile consists of twisted-pair phone wires or coax cable Annoyingly bandlimited, especially in the upstream direction Capacity diminishes with distance from node The broadband subscriber lines available to most users will be inadequate for good user experience with WebRTC multimedia services.

25 Are Telecoms and Triple-Play providers holding out on us? Fiber-to-the-Home (FTTH) is proven, off-theshelf, cost-effective technology. Passive Optical Networks 155 Mbps upstream In the UA ervice providers are slow to roll out FTTH. They prefer to stick with ADL2+ over copper wires? Lobbying and court cases permit them to avoid a large investment. Longstanding public policy and regulatory problem that is holding back innovation. ource: Fiber to the Home Council WebRTC developers and service providers need be aware of this challenge ee Ferguson, Charles, Anatomy of a Market Failure and Policy Dilemna, Brookings, 2004

26 Questions 1. What is the biggest issue with large party video? 2. hould WebRTC implementations use routing or MCUs? 3. When do MCUs make sense for WebRTC conferencing? 4. When does routing make sense? 5. hould developers have the own central facilities for media or use available cloud offers? 6. How many peer to peer video sessions can you manage before needing a central facility? What are the limiting factors? 7. How good are the Open ource MCUs out there?