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Technical Education What is conferencing? Lesson 1 Index Click here to move on © Copyright Ezenia Inc, 2000 Lesson 1 - objectives In this lesson you will look at the types of information that may be included in a Multi-Media conference. It will introduce you briefly to the components of the two main types of conference; multi-point and point-to-point conferences. You will also gain an overview of underlying networks for H.320 or H.323 conferences. If you are new to multimedia conferencing, this lesson will explain some of the basic concepts of such systems, to prepare you for the more detailed information in later lessons. Next Beginning Help 2 © Copyright Ezenia Inc, 2000 What is conferencing? Multimedia Conferencing brings together people in different locations through the exchange of real-time audio, video and data. Each location uses a conferencing system, or Endpoint, to communicate. Conferences can consist of any combination of the three types of information – Audio, Video or data. Next Previous Beginning Help 3 © Copyright Ezenia Inc, 2000 Conference types There are two different ways of defining the conference type. The first method is to describe it by the number of endpoints involved. In this case conferences are either point to point, with only two participating endpoints or multipoint, where more than two endpoints are included. • What is a H.320 Conference? • What is a H.323 Conference? The second method is to describe it by the underlying network type. Conferences that use connect using Wide Area Networks only are defined by the H.320 standard. Conferences that run over IP based networks are defined by the H.323 standard. Review Questions Previous Beginning • Tell me more about a point to point conference • Tell me more about a multipoint conference Help 4 © Copyright Ezenia Inc, 2000 Multipoint conference A conference is said to happen whenever two or more endpoints connect and share real-time information. Conference Types Beginning A Multipoint conference has multiple endpoints connected together. It also usually has another component, a Conference Controller, to manage connections into the conference Help 5 © Copyright Ezenia Inc, 2000 Point to point conference A conference is said to happen whenever two or more endpoints connect and share real-time information. Conference Types A Point to Point conference is when two endpoints are directly connected and no other party is involved. Beginning Help 6 © Copyright Ezenia Inc, 2000 H.320 conferencing • What kind of network do H.320 conferences use? • What are its benefits? • Why do we need a standard? Conference Types Beginning Help 7 © Copyright Ezenia Inc, 2000 H.320 networks Such systems were developed to take advantage of the high speed Wide Area digital communication services offered by telecommunications companies around the world. Typical networks that are suitable for these connections are ISDN switched services and T1/E1 leased services. These are known as Wide Area Networks (WANs). Previous Beginning Help 8 © Copyright Ezenia Inc, 2000 H.320 benefits As the underlying high speed networks that support H.320 are compatible, it allows intercontinental conferences to take place. This gave rise to one of the major benefits that of saving travel costs and time. H.320 conferences have been used throughout the business world since the mid 1980s. Previous Beginning Help 9 © Copyright Ezenia Inc, 2000 H.320 standard While the underlying high speed networks that support H.320 are compatible, there is more to compatibility than allowing the physical circuits to communicate. The data (digitised audio, video and file information) must be understood between the endpoints, and a common control language must exist between all parts of the system. This is the purpose of the H.320 standard. Previous Beginning Help 10 © Copyright Ezenia Inc, 2000 H.323 conferencing • What kind of network do H.323 conferences use? • What are its limitations? • What are its benefits? • Why do we need a standard? Conference Types Beginning Help 11 © Copyright Ezenia Inc, 2000 H.323 conference networks The most widely installed networks are those that exist within a company - Local Area Networks (LANs). For reasons of economy as well as the scope for considerably enhanced services, there has long been a need to run conferencing over the LAN. Unfortunately the typical traffic on a LAN (very irregular volumes, throughput critical, but not end to end timing critical) does not fit very comfortably with real time multimedia traffic (large, fixed volume with very critical timing constraints). Two developments in the 1990s changed the situation higher bandwidth networks (specifically 100 Mbps Ethernet), and mechanisms to control how network capacity is used. These made LAN based multimedia practical. Previous Beginning Help 12 © Copyright Ezenia Inc, 2000 H.323 standard There exists a need to ensure endpoint to endpoint compatibility. The H.323 standard addresses that, but also includes the extra elements needed to allow operation on a shared bandwidth, connectionless network. So it is possible to “inter-network” between LANs using standard techniques, but as it is a new standard, it should be approached with care. Previous Europe Sales USA Sales Marketing Asia Sales Beginning Help 13 © Copyright Ezenia Inc, 2000 H.323 benefits The ability to have short, regular meetings without the need to move people away from their desk is of benefit within one large building. When companies occupy multiple buildings in multiple locations then the benefits increase significantly. The fact that these facilities can be provided without installing any major new infrastructure (cabling etc.) will further encourage their adoption. Previous Because H.323 uses existing communications techniques (TCP/IP) it will open up the possibilities of easier intercompany conferences. • Beginning As it uses TCP/IP, can we conference across the Internet? Help 14 © Copyright Ezenia Inc, 2000 H.323 over the Internet The Internet, of course, is the main TCP/IP based network in the world, and is open to everyone. Already various multimedia sessions are held over the Internet; however it is likely that further advances in technology will need to be applied before full multimedia conferencing is regularly conducted over this network. Previous Beginning Help 15 © Copyright Ezenia Inc, 2000 H.323 limitations The main issue being considered with H.323 systems is that of it’s need for significant amounts of bandwidth along with critical end to end timing constraints. Within a company most of these matters can be resolved by increasing the network bandwidth, and monitoring the impact of any changes. For connections to other LANs and/or the Internet more serious considerations need to be made. Work underway within various standards bodies however is ensuring that these problems are being overcome. Previous Beginning Help 16 © Copyright Ezenia Inc, 2000 Review Question 1 H.320 is the standard applied to IP based conferencing. True False Choose your answer Conference Types Beginning Review that information again Move on to the next question Help 17 © Copyright Ezenia Inc, 2000 Wrong Answer H.320 is the standard used for WAN based conferencing. H.323 is the IP based standard. H.323 Beginning Review that information again Move on to the next question Help 18 © Copyright Ezenia Inc, 2000 Correct Answer Well done H.323 is the IP based standard. H.323 Beginning Review that information again Move on to the next question Help 19 © Copyright Ezenia Inc, 2000 Review Question 2 Which of the following changes in Networks facilitated the introduction of LAN based conferencing? Higher bandwidth networks Different cable types Faster servers Conference Types More literate users Choose your answer Review that information again Beginning Help 20 © Copyright Ezenia Inc, 2000 Wrong Answer While the introduction of different cable types have led to more flexibility in network design, they have not made any significant difference to the provision of LAN based multimedia conferencing. The arrival of high speed networks, like fast Ethernet, have made the introduction of H.323 LAN based multimedia conferencing possible. Conference Types Beginning Review that information again Help 21 © Copyright Ezenia Inc, 2000 Wrong Answer While the introduction of faster servers have had a significant effect on the amount of other types of data a LAN may carry, they have not made any significant difference to the provision of LAN based multimedia conferencing. The arrival of high speed networks, like fast Ethernet, have made the introduction of H.323 LAN based multimedia conferencing possible. Conference Types Beginning Review that information again Help 22 © Copyright Ezenia Inc, 2000 Wrong Answer The increasing awareness of network users about what networks can do for them may have led to the demand for LAN based conferencing. However, until there were high speed networks available to meet that demand, users could not be provided with such conferencing. The arrival of high speed networks, like fast Ethernet, have made the introduction of H.323 LAN based multimedia conferencing possible. Conference Types Beginning Review that information again Help 23 © Copyright Ezenia Inc, 2000 Correct Answer Well done The arrival of high speed networks, like fast Ethernet, have made the introduction of H.323 LAN based multimedia conferencing possible. Conference Types Beginning Review that information again Help 24