The IP multipoint units we tested here work fine for up to four attendees, but if your client needs more than one videoconference simultaneously or you plan on selling a videoconferencing service, youll need to purchase a separate MCU, some of which can support up to 400 conferencing ports.
These server-based units from companies such as RadVision (www.radvision.com), Accord (www.accordnetworks.com) and CuSeeMe (www.cuseeme.com), offer scalability and rich feature sets to handle larger-scale multipoint videoconferencing.
While the units we tested (which combine an end point with an MCU) are fine for a single, small multipoint conference, these servers can handle the load from more than one conference and usually include a gateway and gatekeeper, to boot. The user can simply dial a number and the MCU automatically sets up the conference, then anyone else who dials that number can join the conference. The CuSeeMe Conference Server, a software-based H.323 MCU, even integrates with Microsoft Exchange 2000 so users can schedule the MCU like any other resource.
The MCUs come in all sizes and prices. RadVision for example, offers the ViaIP product family, an MCU aimed at service providers and enterprises that integrates a multimedia gateway, data collaboration and a gatekeeper into a single platform that can deliver 400 simultaneous video calls. On the other hand, it also has a scaled-down version in its MCU-323, which supports up to 15 videoconference calls.
Accord Networks, which was recently purchased by Polycom, also has multiple offerings. Its high-end unit is the MGC-100, which can handle 96 end points while also serving as a gateway to ATM and ISDN networks. Its lower-end version is IP only (although it can be upgraded) and supports 48 end points.