Global Serverless Videoconferencing over IP

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Global Serverless Videoconferencing over IP

• Thomas C. Schmidt, Matthias Wählisch, Hans L.
  Cycon, Mark Palkow schmidt, mw, hcycon,
  mpalkow_at_fhtw-berlin.de
• FH für Technik und Wirtschaft Berlin

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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

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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

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Agenda

• VCoIP communication paradigm
• VCoIP - where lt are we gt going?
• A distributed communication scheme
• User Location
• Group Conferencing
• The daViCo conferencing System
• Properties, Implementations
• Wavelet Video Codec
• Conclusions Outlook

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VCoIPCommunication Paradigm

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

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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 ltusergt_at_ltSIP-servergt
• Proprietary Centralised Services (MS NetMeeting)

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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

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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

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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

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User Session Location

• Directories in domains locale to users
• Map Email to current Host-IP
• Directory location via
• DNS MX-Record
• Name convention usl.ltmx-domaingt
• Decentralised administration authentification

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A User Location Scheme
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LDAP Session Data

• DN mailcharly_at_brown.net, dcapplication
• Note LDAP allows for authentification
  encryption

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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

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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

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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

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Wavelet Coder and Decoder
Image
Lossless Decorelation
Lossy Quantizer
Lossless entropy coderPACC
Image
PACC Principle of Partioning, Aggregation and
Conditional Coding
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PACC Decomposition
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Wavelet Transform
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VCoIP in Praxis
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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