BOSTON(06/12/2000) - When talk turns to videoconferencing, the focus of the conversation usually revolves around point-to-point systems based on old-world ISDN technology or new-world IP. Sure, both technologies have their shortcomings, but ISDN systems based on the H.320 standard typically offer good audio and video quality, while IP systems based on H.323 can deliver video to end users' desktops over existing network connections.
Still, if you're looking for alternatives that cost less or don't put as much strain on your network, there are new choices emerging.
One alternative, offered by Video Network Communications, Inc. (VNCI) of Portsmouth, New Hampshire, bypasses the corporate data network altogether.
Another alternative is to use IP Multicast to connect users in a conference without the need of expensive hardware in the middle.
Christine Perey of Perey Research and Consulting in Placerville, California, says the new technologies aren't for everyone. For instance, she says H.320-based ISDN systems may still be the way to go for firms that need to do limited point-to-point conferencing with excellent video quality. But for organizations trying to tie lots of participants into a conference from desktops, something like VNCI's offering or IP Multicast could be better choices, Perey says.
VNCI's VidNet uses customers' phone lines to transmit audio and video signals from point to point. Like DSL, VidNet uses a higher frequency rate than those for regular voice communications, letting the phone and conferencing system be used simultaneously.
A user connects VNCI's VidModem to a multimedia PC and a phone line, then uses a Java applet to place, receive and manage videoconference calls. At the heart of the system is a VNCI switch, which sits in the phone closet and ties into the company PBX. The switch is actually a server that routes video calls between endpoints and to the outside world.
VidNet's cost is competitive with traditional ISDN-based units, with an average starting price of $1,650 per endpoint. (This is the total cost, including switches and other hardware.)Greenberg Traurig, a law firm with 18 offices around the globe, chose VNCI's technology for several reasons. First, the main interface, based on a directory, is simpler to use than those that front ISDN systems Greenberg Traurig evaluated, says Jay Nogle, director of legal systems for the firm.
"Second, our previous system used ISDN-based units installed in large conference rooms, which limited their accessibility," Nogle says.
The VNCI model has let the firm expand videoconferencing capabilities to all its conference rooms at six sites, and even to some employees' desktops. At each site is a VNCI switch, with all the sites tied together by 384K bit/sec ISDN lines. Instead of having multiple ISDN lines into one facility, only one is now needed. When a Greenberg Traurig attorney needs to tie multiple outside participants into a conference, the company uses a third-party bridging service, Nogle says.
Nogle could not put a number on how much money the new system has saved the firm.
For those wanting a cheaper alternative that does not involve specialized hardware, IP Multicast technologies could be an answer.
Coming out of Lucent Technologies Inc.'s Bell Labs, the iCosm Collaborative Video tool is a PC-based application that can allow up to 20 simultaneous users into a conference without the use of a central server or multipoint control unit (MCU), says Brian Katz, general manager of IP collaboration at Lucent. It should be noted, though, that a special PC card is needed for those that want to view all conferencees on their PC screen at the same time. Katz claims the iCosm application can achieve TV-like quality of 30 frames per second.
The iCosm application uses multicast where available and unicast everywhere else. Each endpoint sends its own audio/video stream and receives each of the other conferencees' streams simultaneously using an algorithm developed by Bell Labs. Multicast is more network-friendly than unicast, as the former only uses a single stream to serve all users. Katz says the iCosm technology costs just 10% to 20% of an MCU-based system, with pricing starting as low as $150 per desktop.
A drawback of any approach that uses multicast is the entire network path over which the conference's packets travel must be set up to handle IP Multicast traffic. In a LAN, this isn't much of a problem because IS controls the whole domain. But when a call crosses the Internet, the chances of the entire path being multicast-enabled are slim.
VCON in Austin, Texas, uses a different approach than Lucent. Some of its higher-priced endpoints are equipped with what the firm calls Interactive Multicast technology, which lets the units act like servers and send multicast streams. One endpoint is designated as the chair of the conference and is in charge of managing it. If another VCON endpoint wants the floor, the chair can pass control to that person's endpoint while he or she speaks. Behind the scenes, the source of the multicast broadcast is shifted from one endpoint to the next. The transition is seamless to other participants, including those in view-only mode, says Gordon Daugherty, a senior vice president at VCON. The firm's endpoints come in stand-alone models that can attach to a television and desktop models that can plug into a PC.
Daugherty says the VCON technology, which does not require an MCU, is best-suited for training and educational applications involving large audiences and few speakers.
Also testing IP Multicast are universities and other organizations participating in Internet2, the high-speed, experimental version of the Internet. These organizations are trying IP Multicast with a combination of tools such as Cisco's IPTV and VIC, a public-domain videoconferencing application. In these tests, each conference participant points his software to send to and receive from a predetermined Class D IP address designated for IP Multicast broadcasts. Participants can view a multicast conference using a client such as RealPlayer or IPTV. If they have a camera and microphone as well as software capable of multicasting, they too can participate interactively.
Market research firm International Data Corp. in Framingham, Massachusetts, predicts that shipments of videoconferencing endpoints will explode from less than a half million per year last year to more than two million by 2003. So it may be only a matter of time before your company needs to make a choice about videoconferencing systems. When making the decision, remember that it's more than just picking H.320 or H.323 systems - it's also a matter of finding the right fit.