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January 1999

Mixed-Media Conferencing:
Getting Down to Business


The traditional phone call has limits in business. When several colleagues want to review presentations or a new product design, or when trading partners simply need to look one another in the eye, audio is insufficient. Mixed-media calling, however, offers audio, video, and data converged on the same IP network and endpoint so that multiple users can share computer programs with one another in real time.

When Internet telephony phones and applications were first developed, they were viewed as toys by hobbyists who used them to make cheap phone calls over the Internet. But the IP communication servers of today empower telephony as a dependable tool that allows businesses to extend themselves through the Internet to satisfy customers and streamline business processes. Mixed-media calling, for example, can make workers more productive while eliminating the travel and expense required for in-person meetings. Business users, however, will be wary about adopting converged IP communications en masse until the technology truly becomes a business tool instead of a novelty for early adopters. In addition to providing impressive functionality, this type of calling must integrate with the business environment in an easy, natural way, and be as dependable as the process it replaces.

Internet telephony freeware first comes to mind when someone mentions mixed-media calling over IP. But in order to make an Internet call with most freeware, users need to: look up a team member's phone number; call to find out that person's IP address (or learn which directory server has the listing); make yet another phone call to check whether the person is there; enter the IP address or directory server; try talking; then possibly contact the person over the regular phone network to actually speak to him or her. Multipoint conferencing is possible, but only after a lot of work setting up the call. After a few attempts, users typically give up or use the freeware for a specialized task like data conferencing.

New mixed-media conferencing servers end the frustration of freeware by enabling users to dial each other's desktops using their phone numbers. Servers ensure reliable quality and enable converged business applications like collaboration and customer care. Since business decisions hinge on dynamic, multiparty communications, these servers can handle many users at once in a spontaneous mixed-media conference - no need to reserve a conference bridge - and support hundreds of simultaneous connections. In addition, linking mixed-media servers to PBXs brings traditional phone features and manageability to endpoints, including call detailing for billing, hunt group access, and administration of user permissions such as "no outbound long-distance calls after 6 P.M."

Other features include the ability to:

  • Conference through desktops, telephones, and any ISDN-based video conferencing system (the server acts as a gateway).
  • Add or drop parties at will.
  • Receive calls even if PCs are shut down for the night by forwarding them to voice mail or a receptionist.
  • Support Windows and UNIX clients on the same server.
  • Conserve bandwidth if possible.
  • Enjoy 7x24 support, same-day replacement of hardware and software, and remote monitoring and management.

A key concern with IP mixed-media conferencing is the quality of the communication, and engineers are building Quality of Service (QoS) into advanced mixed-media call servers for the following:

Compromising on audio quality is unacceptable. The latest mixed-media call servers limit end-to-end voice delay to less than 400 milliseconds, or below the noticeable range. A silence suppression feature transmits only datagrams containing speech, not silence. Multipoint audio streams are conferenced in hardware at the server instead of the endpoint, so the server uses only one audio stream to carry the conferenced stream over the WAN. System management commands reserve a specified amount of WAN bandwidth for audio traffic, meaning new video and data sessions are denied in heavy load situations, since audio calls are usually a higher priority.

Advanced mixed-media call servers use lip-synchronization features to coordinate audio and video. Servers and clients also support IP multicast for video traffic, which utilizes LAN and WAN bandwidth efficiently by using a single stream to send video to multiple endpoints. The system administrator can also limit the total WAN bandwidth allowed for video streams.

The important QoS consideration in data conferencing is synchronizing updates that the user controlling the file or application is making at the time. Mixed-media call servers send updates to other parties in the conference before updating the user in control so everyone can follow along. Mixed-media conferencing servers can also split traffic, routing T.120 traffic over the data WAN while audio and video traffic goes over the PRI WAN for QoS.

Mixed-media conferencing will allow Lockheed Martin to hold virtual meetings and group reviews of avionics software code as they begin developing the Joint Strike Fighter, due in 2008. The company is teaming up with other major manufacturers to produce the first demonstration planes of the aircraft for the U.S. Air Force, U.S. Navy, U.S. Marines, and British Royal Navy.

Some companies have taken mixed-media conferencing to their Web sites, enabling customers to join them in multimedia collaboration. Traditionally, Web surfing customers who want to communicate with a company need to log off and dial a phone number listed on the Web page, or at best use an e-mail hot link to send a message that might be answered in days or weeks. New Internet call centers, however, provide customers with the ability to contact vendors through phone, Internet fax, e-mail, and text chat.

With one mouse click, customers can initiate a mixed-media call over the same line they use for Internet service. Once connected, customers and call center agents can view Web pages together, chat by text, or even request a callback to their phone. The same agent can handle a regular toll-free voice call in one instant, followed by an IP voice call, e-mail "call," and a text chat.

Micron Electronics, a vendor of custom-designed PCs, lets its Web customers talk with an agent via an "Internet call center," by which both the customer and the service agent look at Web pages together and talk or text chat. Micron reports a great increase in customer service. As options like these become available for customers, the opportunity for vendors to do more business expands proportionally. Better Internet call center offerings blur the lines between Web sites and traditional call centers by providing the appropriate service agent with a "screen pop" regardless of whether a Web call or phone call is coming in.

Advanced IP mixed-media conferencing dramatically transcends Internet telephony freeware and other first-generation servers that simply focus on putting voice onto IP. Companies that want to gain a competitive advantage and realize this technology's potential as a business tool need to make sure that their transport network is properly designed, and the business factors are in place. On the technical side, companies must consider appropriate client and wide area access. Numerous papers cover the design issues, proving that technology is available to permit high-quality intranets and reliable Internet applications. From a business perspective, IP convergence applications should be reliable enough to support critical functions, and be easy-to-use extensions of current business applications.

Ease of use and integrated product support differentiate a group of communication products (a telephone, a PC, and a LAN line, for example) and a truly useful converged application. With an adequate network and a converged application, the rest is up to business users. Along with their service providers, they will be the ones to decide how to make converged IP applications work for them, and to transform this technology into much, much more than a novelty.

Bryan Katz ([email protected], 732-957-5453) is general manager, IP Business Communications, Lucent Technologies. Lucent Technologies, headquartered in Murray Hill, NJ, designs, builds, and delivers a wide range of public and private networks, communications systems and software, data networking systems, business telephone systems, and microelectronic components. Bell Labs is the research and development arm for the company. For more information on Lucent Technologies, visit the Web site at www.lucent.com.

The Video Conferencing Defense


Time has an exceptionally important meaning in the judicial and law enforcement communities, and saving time is equally vital. This is why Mike Effner, MIS director for the Hillsborough Public Defender's Office in Florida, has been working with various state, county, and city law enforcement agencies to improve communications among public defenders, law enforcement officers, and inmates.

One might argue that by MIS standards, Mr. Effner is a risk taker. He began purchasing and developing a robust ISDN infrastructure for desktop video conferencing in the fall of 1996, significantly ahead of mainstream law enforcement communities. But over time, the popularity of Intel Business Videoconferencing systems (IBVC) with ProShare technology has grown. Today, the Hillsborough County Public Defender's Office uses more than 112 desktop video conferencing systems, including those installed in law enforcement agencies elsewhere in the district.

Public defenders' regular trips to the Hillsborough County Sheriff's jails can cause a bottleneck in the judicial process. If video conferencing reduces the need to travel to the jail, taxpayer dollars will be saved. Mr. Effner figures that eliminating non-productive time associated with travel could save the office between $350,000-$400,000 annually. "So, the cost of the whole technology package necessary to video-enable the jails would be covered by the funds the office saves in one year, at most!" said Mr. Effner.

After proving that public defenders can save time and resources with the systems, Mr. Effner started working with Sheriff Cal Henderson, Captain Tom Hall, and other members of law enforcement to explore the possibilities of expanding the applications. Hayes Computer Systems, a Tallahassee-based systems integrator, came in to research the infrastructure needed to coordinate a virtual consultation network for the jails and public defender's office. "We began with one application, but once we got into the details of the jail operation we found that there were several other applications that could use the same infrastructure," recalled Debra Oppenheim, contracts and account manager for Hayes.

Ms. Oppenheim had established relationships with video conferencing sales engineers at Intel Corporation during the past 18 months. Intel introduced Hayes to vendors and contractors, including White Pine Software of Nashua, NH; RADVision, Inc. of Mahwah, NJ; and Brinckmann & Associates of Atlanta, GA. Ms. Oppenheim found that these companies could contribute to the development of the county LAN-based video conferencing solution with seamless internetworking to H.320 systems in the WAN.

After performing their own research, members of the sheriff's MIS department knew they wanted to go with an open infrastructure such as PCs with standards-compliant add-ons. By adopting internationally accepted protocols, the sheriff's office would be able to obtain video conferencing products from different sources.

Three county agencies (the Hillsborough County Court Circuit, the Public Defender's Office, and the Sheriff's Department) share a high-speed ATM backbone running at OC-12 (622 Mbps throughput) into four Cisco Catalyst 5500 Ethernet ATM switches. The switches then route traffic to ten 100 BASE-T switches, using Cisco's EtherChannel technology. EtherChannel allows bonding of four 100 Mbps segments into one, so that between the switches and edge devices, 400 Mbps bandwidth supports each of the hub stacks in the jails.

"We knew that off the shelf components were a part of the equation since we were going to deploy all ATM in the backbone, 100 Mbps Ethernet in the facilities, and H.323-compliant video conferencing systems for each PC on the sheriff's LAN. The exciting thing is that we are building a multivendor H.323 solution and these products are interoperating," explained Ms. Oppenheim.

Eight basic rate ISDN lines (128 Kbps each) will come into the Ascend MAX4000 multiplexer from the local GTE Central Office. These ISDN circuits will permit users with H.320-compliant video conferencing systems to connect to any of eight ports on two RADVision L2W-323 gateways. The gateways will only accept calls from the end points that they have been programmed to recognize, keeping the system secure from unwanted video visitors. The gateways will then resolve the IP address of the pod (where inmates are held) based on the phone number prefix entered by the public defender when placing the call.

A community services officer, notified in advance of the defender's intention to visit via video, will direct an inmate to the appropriate video conferencing station on the network. The H.320 video stream that entered the L2W-323 gateway will now run in native H.323 mode.

A call from the gateway - once inside the IP environment - will negotiate a live session with the video conferencing system in the pod, and a dedicated point-to-point conference can begin. The inmate systems and community services officers' stations will be equipped with 333MHz Pentium II processors, 64MB of RAM, and IBVC H.323 conferencing add-on kits. The 100 Mbps Ethernet cards will provide ample bandwidth for the incoming and outgoing video and audio streams.

Dr. Michelle Blank is president of RADVision, Inc. RADVision provides core technology components for building complete H.323 multimedia internetworking solutions. For more information, visit their Web site at www.radvision.com.

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