Presents 2005 IMTC Forum

1. Presents 2005 IMTC Forum

2. NAT/Firewall Traversal ITU Standardization Progress Dave Lindbergh,

3. Contents • Why NAT/FW traversal is important • Why took so long to fix this? • ITU strategy & schedule • Key objectives for traversal standard • “H.FANTAS” • “H.MA” • Conclusion & prospects 3 IMTC Forum – May 2005 – Eibsee, Germany

4. Why NAT/FW Traversal is Important • H.323 was approved by ITU in 1996 (!) • ISDN would surely be gone by 2000… • It’s 2005… • Virtually all inter-company calls are ISDN • ISDN is comparatively expensive • Reliability is still a problem • This is holding back VC market growth! 4 IMTC Forum – May 2005 – Eibsee, Germany

5. Why no Inter-Company H.323? • Because of NAT/FWs • H.323 video conferencing is a niche • Compared to Web, Email, FTP, etc… • Some H.323 support in NAT/FW devices • Too often: Limited, obsolete, misconfigured • Minimal IT staff H.323 expertise • In practical terms: It rarely works 5 IMTC Forum – May 2005 – Eibsee, Germany

6. What took so long? • IETF kept promising • But not delivering • Lots of “religious” disagreements • ITU was too patient…but not anymore • Key decision for 2005-08 Study Period: • Focus narrowly on H.323 solution, in ITU • ITU-T Q5/16 setup (R. Gilman, Avaya) 6 IMTC Forum – May 2005 – Eibsee, Germany

7. November 2004 – Key Objectives • Support enterprise scenarios • Support service provider scenarios • Support both enterprise & service provider scenarios • Support “multi-level realms” • Support double-NAT/FW situations • Support “simple” FW/NAT configurations • Allow simple administration to manage H.323 traffic • Support existing deployed NATs & FWs • Permit H.323 calls by default unless actively blocked • Support existing deployed H.323 endpoints 7 IMTC Forum – May 2005 – Eibsee, Germany

8. March 2005 – AVD-2698r1 “FANTASMA” • A joint proposal of Tandberg, Polycom, and Radvision • Real cooperation to fix NAT/FW problem! • “H.FANTASMA” • Firewall And NAT Traversal Applying Signalling and Media Association (!) • Approved in Principle by ITU-T Q5/16 8 IMTC Forum – May 2005 – Eibsee, Germany

9. Splitting the Baby • “H.FANTAS” • H.323 signaling traversal & call setup • G. Chamberlin, editor • “H.MA” • H.323 media traversal • A. Ruditsky, editor • Schedule: drafts 5/2005, approval 8/2005 9 IMTC Forum – May 2005 – Eibsee, Germany

10. “H.FANTAS” • Architecture: SBC (“Traversal Server”) • “Helper” entity in cloud • May be co-located with H.323 Gatekeeper • Key ideas: • All traffic originates inside NAT/FW boundary • Port symmetry lets response to pass thru NAT/FW • This opens bi-directional “pinhole” thru NAT/FW • Keep-alive packets sent periodically • To keep “pinhole” open 10 IMTC Forum – May 2005 – Eibsee, Germany

11. “H.FANTAS” Principles • Provision for optional multiplexing of traffic onto a small number of ports • Bootstrap call setup sequence • RRQ registration opens RAS path • RAS is used to open H.225.0 path • H.225.0 is used to open H.245 path • Outgoing calls can start normally • Incoming calls notified via RAS path 11 IMTC Forum – May 2005 – Eibsee, Germany

12. “H.MA” • Depends on H.FANTAS to setup call • Uses similar principles • Symmetrical “pinholes” • Keep-alive packets to maintain path • Optional multiplexing layer • 4-byte unique value identifies RTP/RTCP sessions on same IP address & port 12 IMTC Forum – May 2005 – Eibsee, Germany

13. Conclusion • We are finally going to make H.323 interoperable between organizations! • This will make a lot of users happy! • And encourage VC use with customers, suppliers and partners – a New Thing. • It may mean the end of H.320 in our lifetime! • (But…we’ve been wrong before…) 13 IMTC Forum – May 2005 – Eibsee, Germany

14. Thank you!