Desktop videoconferencing (DVC) products are available for Windows, Macintosh, and Unix machines for circuit-switched digital WANs (ISDN), circuit-switched analog WANs (POTS), and packet-switched LANs.
H.320-compliant videoconferencing kits typically include a camera, a microphone/telephone handset, a codec, an ISDN interface board, and data-conferencing software. They range in price from $1500 to $2000. The lower-priced kits may use software for decompression or for both compression and decompression. Because software solutions rely on the host computer's processor, the faster the CPU, the better the performance users will see.
ISDN service providers may offer kits for less than $1000 as part of a service-contract bundle. You can also purchase DVC systems in
the form of high-end computers with videoconferencing hardware and software already installed. This tends to be the most expensive alternative, with prices hitting $6000.
ISDN Choices
AT&T, Intel, and PictureTel offer complete H.320 kits for ISDN-based conferencing under Windows. AT&T's Vistium 1300 system includes a dedicated processor for compression/decompression; the less pricey Vistium 1200 relies on the host processor for decompression. Both are available as board kits or prepackaged with AT&T desktop systems.
Intel's Proshare, which recently added H.320 support, uses the host CPU for decompression.
PictureTel Live PCS 100
features a high-quality audio connection and full-duplex speakerphone.
Vivo Software, which announced the first software-only H.320 codec, offers TeleWork-5, a less expensive superset of the original Windows product. The package now includes workgroup software, Internet access, remote LAN access, and fax modem emulation
.
Many OEMs use Zydacron H.320 boards, which support 128- to 384-Kbps communications. Zydacron offers a low-level videoconferencing application as well as hooks for other, more comprehensive collaborative software packages.
Macintosh users can find H.320-compliant solutions from Apple, which supports the standard within the
QuickTime extensions
to the Macintosh OS. Sagem USA sells a NuBus H.320 codec board and separate ISDN board.
Gone to POTS
The upcoming H.324 standard and the new chips that perform the H.263/G.723 codec functions promise to combine improved quality with the convenience of POTS. Today, Creative Labs has both PC and Macintosh solutions for POTS connections, and the two are interoperable. VCC offers a proprietary Windows-based POTS product using one to four V.34 modems for high bandwidth. Intelligence at Large sells a Mac solution that works across both WANs (POTS and ISDN) and TCP/IP LANs. Complete kits cost approximately $200
0; the stand-alone software costs $100 to $300.
LAN versions of Proshare, PictureTel's LiveLan, and competitors from Invision, Viewpoint, and Insoft, use proprietary audio- and video-coding algorithms. But LAN conferencing standards do not yet exist, and H.320 does not work in a packet-switched network. Cornell University's CU-SeeMe software for Windows and Macs works over TCP/IP networks, including the Internet. Sun, HP, and Silicon Graphics also provide LAN conferencing equipment.
C-Phone from Target Technologies and Minx from Datapoint move analog video over a dedicated network and often use vacant wires inside standard Ethernet cables. For WAN connections, a shared server provides the required H.320 codec functions. Uncompressed analog video offers superior quality and does not stifle LAN data traffic. However, the scheme is not compatible with Ethernet or Token Ring bridges, routers, or switches. These products cost $2000 to $2500 per desktop, not including the required dedicated server, swit
ch, and hub.
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PictureTel's Live PCS 100 kit supports ISDN and includes a camera, a full-duplex speakerphone, and software.
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Apple's QuickTime Video-conferencing and competing products fr
om Sagem USA bring H.320 support to the Mac.
In Your Face
