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Global Serverless Videoconferencing over IP Thomas C. Schmidt, Matthias Wählisch, Hans L. Cycon, Mark Palkow {schmidt, mw, hcycon,

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Presentation on theme: "Global Serverless Videoconferencing over IP Thomas C. Schmidt, Matthias Wählisch, Hans L. Cycon, Mark Palkow {schmidt, mw, hcycon,"— Presentation transcript:

1 Global Serverless Videoconferencing over IP Thomas C. Schmidt, Matthias Wählisch, Hans L. Cycon, Mark Palkow {schmidt, mw, hcycon, FH für Technik und Wirtschaft Berlin

2 still is the Killer Communication App. in Internet - Why ? is Unique to Computer Networks is reliable and mature is easy and free is accessible everywhere has full infrastructure support

3 What about Videoconferencing over IP (VCoIP) ? VCoIP is Unique to Computer Networks VCoIP is reliable and mature VCoIP is easy and free VCoIP is accessible everywhere VCoIP has full infrastructure support

4 Agenda VCoIP communication paradigm VCoIP - where going? A distributed communication scheme User Location Group Conferencing The daViCo conferencing System Properties, Implementations Wavelet Video Codec Conclusions & Outlook

5 VCoIP Communication Paradigm Video Conferencing Services request for Session Orientation (synchronous service) Person Orientation Coping with Mobile Users (globally) Group Support Support of Privacy

6 Where Are We ? Serious Conferencing Applications via ISDN ISDN-formed ITU-T Standard H.323 –Heavy burdened Infrastructure with Scaling Deficiencies –Addressing via Telephone Numbers –Local Relaying except for Telephony or Meta Directories Session Initiation Protocol (SIP, RFC 2543) –Own SIP Infrastructure or vaguely locatable SIP-Servers Proprietary Centralised Services (MS NetMeeting)

7 Are We Going? Distribution of videoconferencing is retarded by following the track of H.323 and such: –Inertia of infrastructure –Costs –Inadequate, clumsy solutions –Insufficient support of communication requirements We need a new internet-like approach to VCoIP

8 VCoIP Distribution Recipes Provide an easy, intuitive VCoIP solution Provide personal, effortless addressing Provide automatic user location Remain rigorously neutral to infrastructure Avoid costs Focus on distributed, decentralised services Stick to internet attitudes

9 A Distributed, Intuitive Conferencing Framework oIdentify users via Addresses -Well known -Globally unique -Suitable for automatic relaying oPeer-to-Peer principle waives specific infrastructure -Multipoint conferences via multicasting oDistributed, hidden information services oPure software solution

10 User Session Location Directories in domains locale to users Map to current Host-IP Directory location via –DNS MX-Record –Name convention usl. Decentralised administration & authentification

11 A User Location Scheme

12 LDAP Session Data DN: dc=application Note: LDAP allows for authentification & encryption RequiredOptional VCoIPHostNumberVCoIPMcastGroup VCoIPServicePortVCoIPAppID VCoIPServiceProtocolVCoIPAppProtocol VCoIPTimeStampVCoIPMimeType mailVCoIPPrivateipHostNumber cnVCoIPPrivateipServicePort VCoIPStatusFlag

13 NAT Obstructions NAT Gateways firmly object any Videocommunication. Traditional ALGs intrude fundamental infrastructure. Approach: Position USL outside NAT range Restrain NAT-GW from dropping state information Extract IP-Address and Port from packet headers Publish extracted address information to USL

14 daViCo Videoconferencing Software Pure Software solution including multicast/multipoint video communication highly efficient video codec PACC MPEG3 audio encoding buffer latencies about 100 ms application sharing implements peer-to-peer model & usl scheme designed for best effort transport & effortless use

15 Wavelet Video Codec Real-time video codec based on fast low complexity wavelet transform Transforms whole images without blocking artefacts CIF (352 x 288 pixels) at 25 fps performs in real-time on a 500 MHz Pentium Machine with data-rates below 200 kbit/s More efficient than MPEG4 or H.263 coders

16 Wavelet Coder and Decoder PACC: Principle of Partioning, Aggregation and Conditional Coding Image Lossless DecorelationLossy QuantizerLossless entropy coder PACC

17 PACC Decomposition

18 Wavelet Transform

19 VCoIP in Praxis

20 Conclusions & Outlook VCoIP solution based on a light-weight peer-to- peer model. Ready-to-use approach for user addressing & look-up. Future Development: Future of PACC Codec part of ITU-T H264 /MPEG Advanced Video Codec (AVC) Future directory location via DNS Service Record

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