2Agenda H.323 and related protocols Ready for right products Design ConsiderationsExperiences and Suggestions
3What is H.323? A multimedia communication protocol suite Includes voice, video, and data conferencingFor use over packet-switched networks* H.323 is “ITU-T Recommendation H.323: Packet-based multimedia communications systems”
4Elements of an H.323 System Terminals Multipoint Control Units (MCUs) GatewaysGatekeeperBorder Elements
7MCUs For managing multipoint conferences Contains Multipoint Controller (MC) - manages the call signalingMultipoint Processors (MPs) - handle media mixing, switching, or other media processing
8Gateways Interface H.323 to other networks, Composed of MGC handles including the PSTN, H.320 systems, other H.323 networks (proxy), etc.Composed ofa “Media Gateway Controller” (MGC)a “Media Gateway” (MG)MGC handlescall signaling , non-media-related functionsMG handles the media
9Gatekeeper Admission control Address resolution e.g.,Phone number to IP address
10Border ElementsExchange addressing information and participate in call authorization between administrative domainsOften co-located with a Gatekeeper,
11Packet-switched Network An H.323 StackH.323 ApplicationRASH.245RTP /RTCPH.225.0Call SignalingPacket-switched Network
14Past to Present Or was it? H.323 v.1 was published in 1996 was designed for LANsOr was it?Version 1 (1996) was designed with the Local Area Network in mind. H.323 has its roots in the video conferencing area, borrowing much of the multimedia conferencing aspects from other H.32x-series Recommendations, such as H H.323 was intended to allow people on a LAN to conduct an audio, video, and data conference (with the help of T.120). Or was it?Local Area Network
15Past to PresentBut, it was used in WANs, large private VoIP networks, and the InternetIt worked very wellEarly comers to the H.323 market, such as VocalTec, recognized H.323’s potential for Internet Telephony.
16Past to Present H.323 proved that RTP is able to carry real-time audio and video over IP networks that span the globeIndeed, H.323 was much more than a LAN protocolRTP, as probably everyone in the IP Telephony space knows, is the same media transport protocol used by both H.323 and SIP devices. The early designers of H.323 recognized the potential of embracing, not only the packet network, but also the IETF protocols have helped make the Internet what is is today. For this and other reasons, H.323 is well-suited for multimedia conferencing over IP networks, including the Internet.
17Past To PresentRecognizing the fact that H.323 was much more than a LAN protocol, the name was changed in H.323 Version 2 (1998)Enhancements were made, including:SecurityPerformanceSupplementary ServicesScalabilityThe name of H.323 was changed to “Packet-based multimedia communications systems”.
19The Market TodayToday, the biggest market for H.323 applications is Voice over IP. Why?Lack of right video terminals to address:Low bit-rate Internet connections make video and data intensive applications less appealingIt’s a young industry– and with all such industries, it takes time to mature good productsCompanies can provide VoIP services today at a low cost and provide new competition to the incumbent carriers
20Video Communication Era Future, expect to see video and data communication to become more pervasiveBroadband connectivity is making it possibleVideo and data are logically the next services customers expect to find in conference rooms, at home and on their computer screens
21Why current H.323 products is not good? Unstable Video QualityGood over dedicated lines or in demo roomDeteriorates significantly over InternetDifficult to installNot easy to useToo expensiveBusiness model
32Suggested HW architecture P4 for corporate and soho usersSOC = DSP + RSICfor home and personal/mobile usersCameraVGA resolution at 30 fpsHigh-end webcam is good enoughDisplayVGA monitor vs TVSpeaker and MicrophoneHeadphone is uncomfortableConference phone is a good choiceFull duplex and echo cancellation
33Suggested SW Architecture Embedded LinuxSpport P4 & RISC platformsComplete TCP/IP stackEmbedded Windows and GUISmall but richInteroperable vs compatibleStandard H.323Optimized implementation
34Data Conference Work with PC / MS Windows RDP Network Neighbor – Samba Graphical terminalNetwork Neighbor – SambaNetwork file systemMulti-point screen syncT.120H.323 whiteboard standard
35More than Data Conference Distance CollaborationRun programsCo-designLife demonstrationsScratch paper – notepadetc
36Results嵌入式設計、多點視訊會議、影音加密、代碼撥號、來電通知、遠端影音調控、PC網路芳鄰、遠距簡報、電子白板與即時圖文通訊、線上文字交談、彩色傳真、Fax over IP Gateway、影音留言、會議錄影More than a H.323 systemAt an affordable price
39Product Varieties Stand-alone Embedded in LCD monitor/HDTV Embedded in xDSLBuilt-in PDA/PPC/PMP/DSCMust have in mobile phone
40Remarks Internet is ready for video communication H.323 is a valid protocol, SIP simplifies call setupMultimedia communication with Voice, video, text, graphics, 3D,Design issues are on the system integration, HW and SWEmbedded in various products