Deploy CDNs and take advantage of multicast
Raytheon's Tarleton agrees that companies have to engineer their networks as a whole, but he also extols the virtues of video-specific architectures.
For instance, he believes a combination of content delivery network (CDN) technology and IP multicast is essential for delivering video live and on-demand to Raytheon's more than 400 sites. "If you're thinking about live streaming, you need to think about multicast," he says.
IP multicast is a technology that lets a company efficiently deliver streaming media to thousands of receivers by replicating the packets throughout the network. Tarleton warns that there can be hitches, however. "It's not always the panacea it's thought to be when it comes to video. The farther away you get from the multicast publishing points, the more problems you see," he says. For instance, because streaming video uses interframe compression, it needs a key frame. If those packets are delivered out of order, the key frame might be missing, and the video freezes. To deal with this problem, he recommends reproducing the multicast closer to the user.
Tarleton keeps close tabs on the quality of his video streams using monitoring tools that look below the packet levels into the compressed frames. "I'm not looking at every stream, but I've planted some sniffers here and there to look at certain access points," he says.
Tarleton says for further insurance during live broadcasts, he's coupled a CDN with his multicast system to redirect clients closer to publishing points on edge devices across the enterprise. He also uses the CDN for on-demand streams to make sure everything is positioned ahead of time for easy access. "When we first got into video, [CDNs] were expensive. Now, not only are they cheaper, but some of the newer servers have the technology built in," he says.
Although Tarleton has started to dabble in HD videoconferencing, for now he says he allows media groups to shoot in HD and then he transcodes it to the standardized 300Kbps rate for streaming. If his users want the original HD quality, he creates a disc for them.