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

9. Architecture comparison H.323 Top-down Complete Structured Control Tight Compatible Endpoint centric SIP Bottom-up Modular Messy Initiation Loose Extensible Endpoint centric Future: MS / IMS / NGN Megaco/H.248 Top-down Complete Decomposition Network devices No endpoint functionality Protocol independent media services 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 Learning STUN -> TURN -> ICE (IETF) Instructing UPnP (industr.) MIDCOM, NSIS (IETF) Tunneling H.460.17-19 (ITU) SBCs, proxies, other proprietary 3 behavioral traversal solution categories found:

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

14. Requirements for the development kit Integration compatibilityH.323 must, SIP plus networkIP + GWs, traversal plus, ISDN nice software onlyWindows must, Java/Mac/Linux plus user adminLDAP (MS AD) licensingflexible: buy-out... usage based costfeature/capability dependent provisioningGK billingGK

15. Requirements for the development kit Integration compatibilityH.323 must, SIP plus networkIP + GWs, traversal plus, ISDN nice software onlyWindows must, Java/Mac/Linux plus user adminLDAP (MS AD), GK licensingflexible: buy-out... usage based, GK costfeature/capability dependent provisioningGK billingGK

16. Requirements for the development kit Functionality, standards visual25 fps, CIF, 1 Mbps, camera ctrl (720p, 2 Mbps) audio7 kHz (14/20 kHz) presentationH.239 screen sharing (T.120) multipoint4CIF receive, DTMF securityH.235 extensibility(H.460.x GEF for Presence + IM)

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

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