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Global Serverless Videoconferencing over IP

Global Serverless Videoconferencing over IP. Thomas C. Schmidt, Matthias Wählisch, Hans L. Cycon, Mark Palkow {schmidt, mw, hcycon, mpalkow}@fhtw-berlin.de FH für Technik und Wirtschaft Berlin. Email still is the Killer Communication App. in Internet - Why ?.

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Global Serverless Videoconferencing over IP

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

  2. Email still is the Killer Communication App. in Internet - Why ? • Email is Unique to Computer Networks • Email is reliable and mature • Email is easy and free • Email is accessible everywhere • Email 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 < are we > going? • A distributed communication scheme • User Location • Group Conferencing • The daViCo conferencing System • Properties, Implementations • Wavelet Video Codec • Conclusions & Outlook

  5. VCoIPCommunication 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 • Addressing <user>@<SIP-server> • 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 • Identify users via Email Addresses • Well known • Globally unique • Suitable for automatic relaying • Peer-to-Peer principle waives specific infrastructure • Multipoint conferences via multicasting • Distributed, hidden information services • Pure software solution

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

  11. A User Location Scheme

  12. LDAP Session Data DN: mail=charly@brown.net, dc=application Note: LDAP allows for authentification & encryption

  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 Image Lossless Decorelation Lossy Quantizer Lossless entropy coderPACC Image PACC: Principle of Partioning, Aggregation and Conditional Coding

  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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