Visual Communication Development Kits for Business Application Integration

1. Visual Communication Development Kits for Business Application Integration Esa Vitikainen Master’s thesis presentation 5.9.2006 Thesis supervisor: Prof. Östergård Communications Laboratory Helsinki University of Technology

2. Introduction • Quality visual communication to every desk -> Find best technology & provider • How to get to every desk? • useful/fun, affordable, easy, working • personal, mobile, cross the borders • culture >--> visual, online, on-stage • Visual communication <> video conference

3. Contents • Introduction • Multimedia communication architectures • Multimedia connectivity in IP networks • Requirements for the development kit • Development kits available • Conclusions

4. Real-time multimedia communication architectures • H.323 • SIP • Megaco / H.248 • Comparison

5. H.323 • ‘Packet-based multimedia communications systems’ • ITU-T: 1996 v1, 2000 v4, 2006 v6; backward compatible • Entities: Terminal, gatekeeper, gateway, MCU • Closely related to respective ISDN/PSTN/ATM specs • Main function: Tight session control, compatibility

6. SIP • ‘Session Initiation Protocol’ • IETF: 1996 draft, 1999 v2, 2002 RFC3261 • Entities: User Agent, proxy / location / redirect server • text-based transaction protocol (~HTTP/SMTP) for initiating interactive sessions of any type between users • Main functions: Location, invitation, negotiation SIP principles: • End-to-end services • Generally applicable features • Simplicity • Reuse

7. Megaco / H.248 • Media gateway / Device control protocols • IETF & al: 1998-99 -> MGCP; IETF & ITU: 2000 H.248 • Entities: dumb Media Gateways, smart MG Controller • Main function: Gateway decomposition

8. Architecture comparison Megaco/H.248 • Top-down • Complete • Decomposition • Network devices • No endpoint functionality • Protocol independent media services SIP • Bottom-up • Modular • Messy • Initiation • Loose • Extensible • Endpoint centric • Future: MS / IMS / NGN H.323 • Top-down • Complete • Structured • Control • Tight • Compatible • Endpoint centric

9. Architecture comparison Megaco/H.248 • Top-down • Complete • Decomposition • Network devices • No endpoint functionality • Protocol independent media services SIP • Bottom-up • Modular • Messy • Initiation • Loose • Extensible • Endpoint centric • Future: MS / IMS / NGN H.323 • Top-down • Complete • Structured • Control • Tight • Compatible • Endpoint centric SHOULD complement each other. Winner unresolved.

10. Real-time multimedia connectivity in IP networks • Barriers • NAT, FW, Intrusion Prevention System • Effect on each architecture • Solutions • FW traversal • Enablers • Naming / numbering scheme • Directories, presence • Summary

11. Connectivity barriers • Symmetric NAT • arbitrary public transport address for each connection • > pinhole opening from inside FW impossible • Intrusion Prevention System • dynamic NAT/FW/filtering behaviour

12. Connectivity solutions 3 behavioral traversal solution categories found: Learning • STUN -> TURN -> ICE (IETF) Tunneling • H.460.17-19 (ITU) • SBCs, proxies, other proprietary Instructing • UPnP (industr.) • MIDCOM, NSIS (IETF)

13. Connectivity solutions 3 behavioral traversal solution categories found: Learning • STUN -> TURN -> ICE (IETF) Tunneling • H.460.17-19 (ITU) • SBCs, proxies, other proprietary Instructing • UPnP (industr.) • MIDCOM, NSIS (IETF) + economical - deployment - H.460 only H.323 - others non-std. - HW cost + simple, ready - UPnP scalability + long-term, safe - far-away, cost Small advantage: SIP. Smart ICE coming up.

14. Requirements for the development kit Integration • compatibility H.323 must, SIP plus • network IP + GWs, traversal plus, ISDN nice • software only Windows must, Java/Mac/Linux plus • user admin LDAP (MS AD) • licensing flexible: buy-out ... usage based • cost feature/capability dependent • provisioning GK • billing GK

15. Requirements for the development kit Integration • compatibility H.323 must, SIP plus • network IP + GWs, traversal plus, ISDN nice • software only Windows must, Java/Mac/Linux plus • user admin LDAP (MS AD), GK • licensing flexible: buy-out ... usage based, GK • cost feature/capability dependent • provisioning GK • billing GK

16. Requirements for the development kit Functionality, standards • visual 25 fps, CIF, 1 Mbps, camera ctrl (720p, 2 Mbps) • audio 7 kHz (14/20 kHz) • presentation H.239 screen sharing (T.120) • multipoint 4CIF receive, DTMF • security H.235 • extensibility (H.460.x GEF for Presence + IM)

17. Software development kits available fulfilling H.323 IP Windows LDAP VCON(Emblaze) • IL, 1% share, line of losses, SW focus • COM+GUI • client mode • symmetric • 720p receive • flex licensing OpenH323/OPAL • AU, open source, non-profit (consult), small team • DLL, low-level • few codecs • H.460 extensibility • no management • minimal encryption Polycom • US, 40% share, well profitable, HW focus • COM • SIP, UPnP • no camera ctrl • GK port conflict • less CPU load

18. Software development kits available fulfilling H.323 IP Windows LDAP VCON(Emblaze) • IL, 1% share, line of losses, SW focus • COM+GUI • client mode • symmetric • 720p receive • flex licensing OpenH323/OPAL • AU, open source, non-profit (consult), small team • DLL, low-level • few codecs • H.460 extensibility • no management • minimal encryption Polycom • US, 40% share, well profitable, HW focus • COM • SIP, UPnP • no camera ctrl • GK port conflict • less CPU load Technical advantage: VCON (small). Business/political/financial factors rule.

19. Conclusions • Current business market requires H.323 • Tunneling only way between organizations • 2 providers technically close, other factors decisive • SIP will take over; look for dual or converged protocol/philosophy support