Christine Perey
Ever wish that all these videoconferencing codes and acronyms (ISDN, ITU, H.320, H.324, H.323, IETF) would just disappear? That videoconferencing products would interoperate, and real people could get on with the business of talking and seeing one another, like with a telephone, no matter what protocol or network a system happened to use? Well, all that is possible with an emerging class of devices called videoconferencing gateways.
Gateways are network protocol converters (and, in some cases, video "translating" devices) that make it possible for users on different networks to exchange information. Video network gateways add support for mana
ging video and audio data streams over the intersection of two or more networks using different protocols.
"Video gateways ar
en't conceptually novel," says Ami Amir, president of RADVision (Tel Aviv, Israel, and Mahwah, NJ; 201-529-4300 or
http://www.radvision.com
). "We've been delivering H.320 LAN-to-LAN video gateways based on our proprietary middleware for over 18 months, but this new standards-compliant generation of video network gateways is exciting." H.320/H.323 gateways being developed by Lucent Technologies, RADVision, PictureTel, VideoServer, and others let people who have conferencing on their desks get the video/audio "on and off" ramps they need to pass between packet-switched and circuit-switched networks.
PictureTel's (Andover, MA; 508-292-5000 or
http://www.picturetel.com
) LiveGateway is a PC server add-on kit that not only provides bidirectional interoperability between LiveLAN 2.0 or 3.0 (H.323-compliant) clients and H.320 systems, but also enables Intranet LiveLAN conferencing across digital telephone lines (ISDN). The kit ($2995) consists of one LiveGateway full-length ISA/EISA card with an ISDN cable and software.
Similar in basic purpose, RADVision's L2W-323 Gateway/Gatekeeper for IP networks includes a built-in H.323 gatekeeper (providing H.323 call-control services) and allows up to four concurrent calls between IP-based H.323 terminals (with H.261 for video compression and decompression) and remote users connected to the switched public networks with H.320 videoconferencing systems, at speeds of up to 384 Kbps per call. Prices start at $5950.
VideoServer (Waltham, MA; 617-229-2000 or
http://www.videoserver.com
) and Cisco Systems (Mountain View, CA;
http://www.cisco.com
) have announced plans to collaborate on the development of gateways. Under the agreement, Cisco will OEM gateway modules from VideoServer to enable conferencing between LAN and WAN end points. VideoServer has been demonstrating its gateway technology at major venues ever since. Pricing and availability have not been announced as of this writing.
Murray Hill, NJ-based Lucent Technologies' (
http://www.lucent.com
or 888-458-2368) long and illustrious history
on the PBX stage makes it a natural for the gateway business. Bruce Tillinger, market manager for Lucent's multipoint products, sees H.320/H.323 gateways as critical components of business environments. "Going forward, H.320 is going to continue, but H.323 will make its way later this year, and it is going to be critical for our customers to be able to have a seamless way to converse with people, regardless of the networks or the protocols in use at the various end points. Therefore, our solutions will include H.320/H.323 gateway functionality."
If you are evaluating potential gateway providers, besides examining the company's basic engineering and roots in networking, you should also closely examine the extent of their standards compliance (many product data sheets read "H.323-ready," but full H.323 is envisioned as an update), call-control and gatekeeper functionality, and expansion, especially in the number of connections the gateway can support simultaneously in its basic configuration. Also, verif
y that the LAN protocols as well as all the videoconferencing hardware and software in use are, in fact, fully supported in the gateway.
Checking on these features before you invest in a provider can save you from unpleasant surprises down the road.
Video Highway On-Ramps
