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Feature Article
August 2000


Visually Enabled Interactive Web Sites


Real-time interactive visual communications have been available for some time, yet have struggled to become widespread applications. To date only niche markets, such as distance learning, telemedicine, and corporate video conferencing have seen their benefits and adopted use. The common opinion has been that the required infrastructure, the complexities of placing calls, the costs of communication, and the integration of video and data on legacy systems were preventing the acceptance of visual communications in wider markets. Thanks to the increasing use and accessibility of the Internet, as well as the reduced costs of transferring information over this medium, the dream of interactive visual communications is very close to becoming a reality. It won't be long now before we see the emergence of a new breed of Web sites -- visually enabled interactive Web sites -- that will allow us to seamlessly interact and communicate in ways never before possible.

The telecommunications industry has been undergoing a "convergence" revolution. Convergence refers to the idea that all media types -- audio, video, and data -- are streams of data that can be transported on a single network. The switched network was the traditional transport mechanism when audio was the dominant form of communication. As data has overtaken audio as the dominant medium, we have seen a move to packet-based networks which can efficiently carry voice, data, and video at the same time.

While the convergence revolution has taken off in the network transport domain, to realize its true potential it will also need to reach the business and consumer sectors. For this to occur, the bandwidth reaching the home and office must increase dramatically. While we're not there yet on this front, the belief is that broadband Internet access with quality of service (QoS) will be widely available in the very near future. Whether this occurs over xDSL, cable modems, or some other technology is not important. What is important is that it will occur... and soon.

The convergence revolution, the increasing availability of bandwidth, and erosion of basic Internet connection charges, are making it both possible and necessary for the emergence of a new breed of value-added, revenue-generating services. Internet Service Providers (ISPs) will look to offer new types of visually enabled services as a way to make up for reduced connection fee revenue. Other types of organizations will be looking for new ways to blend video with their Web sites or portals to improve the way they disseminate information and to provide enhanced customer interaction.

The types of services we're likely to see include visually enabled call centers, visual help desks, visual chat rooms, and visually enabled e-commerce. E-commerce companies, for example, will visually enable their Web sites to give customers and prospects a new kind of interactive environment. Have a question about a product on their site? Why not talk to an expert right there and then? Visual call centers will allow corporations to provide better support and offer a more personal touch. All of these types of services will be available to us from our visually enabled TVs or PCs.

In fact, we've already begun to see services that utilize convergence. Multimedia applications such as NetMeeting are enhancing workgroup interactions by allowing video conferencing and application sharing in one environment. Video streaming over the Web has become a popular means of broadcasting training sessions, product announcements, corporate meetings, and even live rock concerts to viewers around the world. There are many new services that we may soon see...

Applications for e-commerce would allow video enabled call centers and virtual meeting room capabilities. Internet users accessing an e-commerce Web site could view multimedia product demonstrations via video streaming. Should they have a question, the user would be able to easily access a live agent by simply clicking on an icon on the Web page. These agents would be visually enabled, allowing them to receive the calling party's video and interact with them to discuss the details of a product found on the Web site. If needed, the agents would have the ability to transfer the user to a product expert for more detailed information.

Today e-commerce Web sites can identify a user's profile and present them with information tailored to their specific interests. If these sites become visually enabled, they could also provide other value-added capabilities, such as the ability to access video chat rooms on topics that would interest the user.

Customer Support Services
An organization's support Web site could include interactive capabilities. It could enable customers viewing a Web site to access a help desk and communicate visually with a support representative. A simple click on an icon and a video call would be placed to the customer support department. Support representatives would be visually enabled so that they could interact with the customer in a two-way video call and even view the same page the customer is currently browsing on their Web site. The call could be made directly or via a queue mechanism, where customers waiting to connect with the next available support representative would receive streamed product information.

Another interactive customer support service would be hosting user group forums. This service would allow organizations to provide training classes, round table discussions, product presentations, or even product announcements from their Web sites.

Corporate Intranet Services
An intranet application would allow a CEO and senior managers of a multinational organization, located in different parts of the world, to address their employees and at the end of their presentations conduct an interactive visual question-and-answer session. Employees would be able to watch and ask questions from their visually enabled PCs. The session could take place over a dedicated intranet or via a virtual private network (VPN). A customized Web page could be loaded onto the company's Web site displaying the meeting agenda, and a welcome message in the video window. Once the conference begins, all of the speakers would be visible and the contents of their presentations displayed on the Web site as they spoke. Viewers of the session would have the opportunity to ask questions by clicking on an icon located on the Web page, which would place them in a call queue. The moderator of the session could select participants from the queue, allowing them to interact with the management staff and ask questions. All of the sites would be visible to one another to provide a real interactive session.

The general architecture for a visually enabled Web site includes an application Web server and one or more multipoint control units (MCUs) -- or video bridges. The application Web server would run the visually enabled services and interact with other host systems, if necessary. The MCU would provide the multipoint video capability, call center type queuing, and transfer capabilities. The MCU would also have the ability to connect with various types of communication protocols and networks, such as H.320 (ISDN video), H.323 (IP video), POTS telephone users, and VoIP users.

The MCU used for visually enabled Web sites will require advanced capabilities. It will need to support an interface allowing the application Web server to manage and control it. The MCU will also need to be able to set up dynamic conference sessions, transfer users from party to party, display multiple sites on the screen simultaneously (continuous presence) and automatically adapt to users connecting with different capabilities, protocols, and from different networks (transcoding). The same basic hardware environment would be suitable for all types of applications, such as an e-commerce service.

We will soon see real-time interactive visual communications become a common part of our daily lives. Thanks to the effects of the convergence revolution, increasing availability of bandwidth, and ubiquitous access to the Internet, visually enabled interactive Web sites will soon be a reality and help transform the way we conduct business, communicate ideas, and interact with others. 

Roni Even is vice president of product planning and advanced development for Accord Networks, Ltd. The MGC-100 Multipoint Conferencing Unit from Accord offers multipoint, gateway, and control. It provides a revolutionary architecture, unprecedented reliability, unparalleled ease of maintenance, a rich feature set, and easy, comprehensive management capabilities.

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Multimedia Conferencing -- What's Stopping You?
Implementing Multimedia Conferencing On A Live Network 


There is still a great fear among network managers about implementing multimedia conferencing on live business networks. The thought of real-time video traffic running alongside mission-critical business transactions sends some network managers into a cold sweat. The good news is that significant progress is being made in techniques that allow bandwidth intensive real-time traffic such as multimedia conferencing to be controlled and deployed. There are five key areas that are aiding the implementation of multimedia conferencing:

  1. Network architecture;
  2. Wide-area traffic management;
  3. Application level bandwidth control;
  4. Firewall access; and
  5. Appropriate media selection.

Before anything else can be considered, it is vital that the underlying network infrastructure provides the correct architecture for supporting real-time multimedia traffic. Most LAN networks today are migrating to, or already have a switched infrastructure -- either standard Ethernet or fast Ethernet to the desk. It is essential that this type of switching technology is provisioned in networks where multimedia conferencing is intended to be used. A shared Ethernet network will start to be overloaded when four or more terminals are involved in multimedia conferencing.

A bigger issue with regard to architecture is the WAN network. Many organizations today, especially in Europe, still have limited capacity in the WAN between different offices. It is not unusual for the links to be 256 Kbps or less. A multimedia conference call using audio and video will need to generate in excess of 200 Kbps of traffic in each direction to ensure that the quality is acceptable. The only solutions available for this problem today are more bandwidth or prioritizing the multimedia traffic over the competing traffic using some kind of wide-area traffic management.

The majority of modern-day routers have the ability to weight or prioritize one type of traffic over another. For example, multimedia conferencing traffic can be given a higher priority than e-mail traffic. Therefore when a video call is made, it will take priority over the link and provide a usable quality of video. Care should be taken to ensure the link does not become saturated. Also it should be ensured that the video call can not assume exclusive use of the link, penalizing all other traffic.

Some routers also offer the support of RSVP, a protocol used to reserve bandwidth over networks. This seems a good idea at first, however, RSVP does have a couple of drawbacks. First, RSVP only allows applications to request rather than reserve bandwidth. If the bandwidth is not available, it can not be allocated. The second, and probably biggest drawback, is that for RSVP to work correctly, the entire network infrastructure must support RSVP.

Traffic prioritization must be considered and applied extremely carefully. If the router cannot distinguish multimedia traffic from the remaining network traffic, then prioritization may actually degrade the conference quality. Other techniques are now available from router vendors such as IP precedence where a router can specifically identify and mark multimedia traffic as high priority. This is done using the precedence bits available in the IP header. This then enables a router network to guarantee priority to any H.323 traffic, irrelevant of packet size or traffic type, over all other traffic.

A gatekeeper is a standards defined function which provides name resolution and call control within a multimedia conferencing network. Some gatekeepers also add the ability to control and manage both access and bandwidth on the multimedia conferencing network. For example, it is possible to set the maximum amount of bandwidth that can be used for multimedia conferencing on a particular network segment. If desired, the granularity can be increased to control bandwidth down to an individual user level. These controls help ensure that the network manager is always in control of the traffic profile on their network.

Multimedia conferencing has traditionally posed a problem to IP firewalls due to the dynamic nature of the call. Only the initial call setup message is passed between end points on a well-known port. All other communication occurs on dynamically negotiated TCP and UDP ports. This has now changed as firewalls have become available with support for multimedia conferencing calls. These devices will monitor communication on the well-known port and analyze any communications exchanged on that port. The firewall can then open up communication channels for the dynamic ports that have been negotiated, but only for the two IP addresses that have been negotiating. Once the call is completed these ports will then be closed again. This method of operation saves the network administrator having to open up a large range of UDP and TCP ports that are accessible to all users. It is much safer to allow the firewall to dynamically open and close ports for specific individuals.

For organizations without H.323-aware firewalls, or that do not wish to modify their firewalls, an alternative is to use a pair of H.320/H.323 gateways to bypass the firewall. This provides an "out-of-band" path that will only carry conferencing traffic and removes the need to modify the firewall (see Diagram).

For organizations that have limitations in their network preventing the full-scale deployment of multimedia conferencing, there are alternative solutions. It is still possible to gain all the benefits of multimedia conferencing, including multi-party conferencing and data conferencing, simply by removing the video element of the conference. Solutions are available today for multipoint conferencing and communication simply using audio and data. These can be initiated using standard applications or can be embedded into Web pages to allow online access to conferences. This dramatically reduces the bandwidth load on the network as today's audio compression algorithms can easily reduce a speech signal to a stream of less than six Kbps. Web integration also significantly aids the ease of use of these solutions.

Network managers have been rightfully wary in the past of implementing multimedia conferencing on their networks, for fear of network collapse. But techniques are now available for bandwidth management both in the local-area and wide-area network. These techniques allow traffic prioritization and bandwidth control. Firewalls can now remain secure even when dealing with multimedia conferencing, and users can select the proper media for their environment. The time is right to start deploying multimedia conferencing. Go on, what are you waiting for? 

Nick Hawkins is director of technical marketing for Ezenia! Ezenia! is a leading provider of multimedia communications servers, enabling group communications within large enterprises, ISPs, carriers, government agencies, and educational institutions. For more information, visit the company's Web site at www.ezenia.com.

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