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Digital Video

Beyond letting you watch a DVD movie or HDTV broadcast in your home theater, digital video has finally come to the enterprise. If your video applications demand high-resolution, full-screen, 30-frame-per-second delivery over a wide area network, you can now meet that need reliably and with relative cost-efficiency.

High-quality video has many practical applications. Organizations from casinos to department stores use digital security cameras and transmit the data across networks to their control rooms. Hospitals and medical schools show broadcast-quality demonstrations of surgical procedures, and hotels store movies and let guests view them at all hours.

Delivering these images over a network requires dedicated equipment, as encoding and decoding such data take more processing power than most CPUs can handle. We tested digital video encoder/decoder units from Amnis Systems, Cisco Systems, General DataComm, Minerva Networks and Optibase in our Dallas labs (see "Picture Perfect Video"). But rather than focus on quality (which is both subjective and standards-based) in our tests, we attempted to break these devices by reordering data packets and generating as much latency deviation as we could. Only our Editor's Choice winner, Amnis' NAC 4000, delivered a consistently steady picture.

Of course, you wouldn't want to transmit critical video data over a lousy network, so you'll need the right setup (see our tutorial, "Building a Video-Friendly Network"). ATM is best, but if you're taking the Ethernet route, make sure your switches support VLANs and your routers support IGMP for multicasting. And throw your Ethernet hubs away.