H.323: Multimedia over IP

1. H.323: Multimedia over IP Paul E. Jones Editor of Recommendation H.323 E-mail: paulej@packetizer.com

2. Past to Present • The first version of H.323 protocol was published in 1996 and was “designed for local area networks” Or was it? Local Area Network

3. Past to Present • The first thing companies tried to do was use H.323 in wide area networks, large private VoIP networks, and the Internet • Guess what? • It worked very well

4. Past to Present • H.323 was an early adopter of such IETF protocols as RTP, which proved its ability to carry real-time audio and video over IP networks that span the globe • Indeed, H.323 was much more than a “LAN” protocol

5. Past To Present • Recognizing the fact that H.323 was much more than a “LAN” protocol, the name was changed in H.323 Version 2 (1998) • Along with the name change came a few important enhancements

6. Past to Present • H.323v2 brought us: • Security • Fast Connect • Supplementary services • Better DTMF relay • Scalability features • Alternate Gatekeepers • Time to Live • Pre-granted ARQs

7. Past to Present • H.323v2 also borrowed something else from the IETF: the URL. Since H.323v2, it has been possible to provide “click to dial” type features using H.323 • H.323v2 also provided solid integration of data conferencing with T.120

8. Past to Present • But why aren’t video and data conferencing systems and applications more prevalent? • VoIP • VoIP • VoIP

9. The Market Today • Today, the biggest market for H.323 applications is Voice over IP. Why? • Low bit-rate Internet connections make video and data intensive applications less appealing • It’s a young industry– and with all such industries, it takes time to mature good products • Companies can provide VoIP services today at a low cost and provide new competition to the incumbent carriers

10. The Changing Market • Tomorrow, expect to see video and data conferencing to become more pervasive • Broadband connectivity is making it possible • Video and data are logically the next services customers expect to find in conference rooms and on their computer screens

11. Wide Support • Where would a protocol be without wide industry support? • Many equipment manufacturers, software vendors, and service providers have built products and services supporting H.323 • A number of organizations, such as ETSI’s Project TIPHON, IMTC, and others have contributed to H.323’s success

12. Strength in Numbers Partial Listing

13. CHINA

14. Lessons Learned • H.323 was criticized early on for being “too slow” to start a call • Fast Connect was introduced to allow media to be established in one H.323 message exchange • Virtually all equipment in the service provider space supports Fast Connect, as well as many of endpoints in the enterprise • Lesson Learned

15. Lessons Learned • H.323 was criticized for requiring TCP, which introduces scalability issues • Annex E/H.323 was introduced to allow H.323 messages to be carried using UDP • Call setup time is improved • Fewer system resources are utilized • Service provider equipment now supports Annex E/H.323 • Lesson Learned

16. Lessons Learned • H.323 has been criticized for being too complex when only a simple audio call is needed • Annex F/H.323 defines a “Simple Endpoint Type” that does not require H.245 and allows one to build a less complex device • These devices meet most of today’s needs • Lessons learned • But what about tomorrow’s needs?

17. Debunking Criticisms of H.323 • H.323 is not too complex • H.323 is feature rich, but not every part of H.323 has to be implemented to build a powerful and useful system • Multimedia over IP, in itself, has a certain amount of complexity associated with it • What complexity does exist is there for a reason and that reason will become even more evident as video and data conferencing become more prevalent

18. Debunking Criticisms of H.323 • The H.323 protocol does not have any known intellectual property claims against it • H.323 does not use only ITU codecs • Almost all VoIP systems use ITU codecs for a good reason– they work very well • H.323 allows the use of any codec

19. Debunking Criticisms of H.323 • Gatekeepers are not bad • Gatekeepers are optional • Gatekeepers provide a consistent means for H.323 endpoints to perform address resolution • Gatekeepers may perform interworking between simple H.323 phones (SET devices) and more protocol-complete H.323 entities • Gatekeepers act as a platform from which powerful new IP-based services may be built

20. Debunking Criticisms of H.323 • H.323 is scalable • Service providers that have deployed H.323 networks have discovered that H.323 allow one to build IP Telephony networks that scale • Just to name a few examples…

21. “Genuity has built a national H.323 network with local inbound dialing reaching 80% of US metros and world-wide outbound dialing.  We are an infrastructure provider offering transport services to enhanced service providers such as: DialPad and PhoneFree, who offer PC-Phone telephony with free call termination in the US;  Pagoo and InfoInteractive, who offer Internet Call Manager services;  and many other messaging service providers having H.323 applications such as unified messaging, or find-me-follow-me services.” – Bob Olshansky, Genuity

22. “Founded in 1996, iBasis is the leader in advanced Internet-based communications. iBasis has built the world's first global IP network that delivers toll quality voice and fax service and other advanced hosted communications solutions, including Unified Communications, to global tier one carriers and other service providers. The iBasis Network is the world's largest international Cisco Powered Network for Internet Telephony and the first to receive the Unified Communications Cisco Powered Network (UC-CPN) designation. More than 100 international service providers are iBasis customers, including 11 of the top 12 U.S. international carriers.” – iBasis

23. “ITXC is the service providers' service provider for Internet telephony and operates ITXC.net, the largest worldwide network for voice on the Internet. Since April of 1998, ITXC.net has been used to provide traditional carriers international call completion with quality good enough for these carriers to use to serve their phone-to-phone customers. ITXC webtalkNOW! Service makes ITXC.net available to Internet portals and other Internet service providers as part of a wholesale web-to-phone offer so that they can offer their end users the quality that phone customers already expect.” – ITXC

24. And of course, let us not forget….

25. CHINA

26. Beyond Voice over IP • Voice over IP opens the door to the next generation of communication products • It will take some time to migrate the world from PSTN to IP networks • H.323 provides excellent interworking between IP networks and the PSTN • H.323 provides a strong foundation for new multimedia products and services

27. IP Telephony IP Telephony with H.323 truly means Multimedia over IP

28. IP Telephony is not Just a Research Topic Anymore • IP Telephony, once only a research topic for some, is now real… there are many deployed products and services that offer IP Telephony services • New kinds of services are now available to customers using IP Telephony that were never possible before

29. H.323 Makes It All Possible • H.323 makes it possible to create and deploy new services quickly and to take advantage of multimedia capabilities • These services can embrace audio, video, and data conferencing

30. Why H.323 for the Service Provider? • H.323 is a proven technology that is utilized in large networks, such as Genuity, iBasis, ITXC, China Unicom, and others • Excellent integration with the PSTN • Gateways and residential devices are in use today

31. Why H.323 in the Enterprise? • Multimedia conferencing devices show the real potential of H.323 and multimedia communication • With H.323 in the service provider network, H.323 is a logical choice for the enterprise • The enterprise customer wants voice, video, and data conferencing capabilities

32. The Future

33. H.323 version 4 • More ways to provide services • Enhancements for scalability • H.323 URL • Enhancements for billing • Enhancements to fax • Much more… please visit the URL below: http://www.packetizer.com/iptel/h323/whatsnew_v4.html

34. Protocol Interworking • Interworking or integrating with other protocols • SIP is gaining in popularity as a VoIP protocol • H.248/Megaco may find its way into many “media gateway” devices, ranging from residential gateways to large-scale service provider gateways • The Bearer Independent Call Control (BICC) protocol will compete with both H.323 and SIP for a place in the service provider network

35. Mobility • Users want mobility • Terminal mobility • “Internet Phone Numbers” that follow them anywhere • Service mobility • Annex H/H.323 is the first step from the ITU, which defined user, terminal, and service mobility • Service providers have the tools to build such services in a proprietary way and are doing some very interesting things

36. Robustness • Robustness work is underway to prevent the loss of a call due to failure of an intermediate signaling entity • Annex E/H.323 (UDP transport) helps • Some devices will keep the call up, even in the face of an intermediate failure– but how do we re-establish the call to do such things as call transfer? • Annex R/H.323 is under development to try to address robustness within the H.323 network

37. H.323 and IP • H.323 was designed to be “transport independent,” but IP is definitely the most popular transport • Work is underway to recommend the usage of H.323 with other IP-based protocols, such as SCTP, CPL, TRIP, and others

38. Concluding Remarks • H.323 is a protocol that leverages the strength of the packet-switched protocols from the IETF • H.323 offers excellent integration with the PSTN • H.323 market penetration is growing • H.323 enables voice, video, and data conferencing • H.323 provides a solid foundation for new services and the continued growth of Multimedia over IP