burst.com Articles-Getting the Picture

"Getting the Picture"
by Kyle Faulkner Chief Technology Officer burst.com

Until recently, delivering audio or video over a network was one of the more challenging tasks an IT manager could face. Following is a look at two media delivery technologies, streaming and bursting, that IT managers should consider when the request to deliver video or audio over an enterprise network arises.

Real-time streaming, such as that available from RealNetworks, is the most popular way to get audio and video over networks and is the prevailing technology for delivering sound and moving pictures on the Internet. Streaming, whether over the Internet or private networks, is a real-time method of moving the media from server to desktop. Provided there are no network inconsistencies, it can work very well to serve digitized video or sound to PCs or set-top boxes. In this article we'll refer to video, but the same principles apply to handling networked, high quality audio.

Here's how streaming works: Each viewer gets a steady stream of data from the server for the video he or she requests. The video is viewed at the same rate on the desktop as it is delivered from the server. In enterprise networks, the IT managers pay license fees for the number of streams they need from the server. If more viewers demand video than there are paid-for streams, then they are told to try again later. A new viewer cannot access the video until another viewer is done and a stream is freed up. Sounds simple and, in a perfect world, it is.

But the truth is, if you need to put video on your network, be afraid...be very afraid. Network managers already face problems of already over-burdened networks. Add to that the chores of having to gauge the impact video has on the network and having to build a system that allows central management of video deployment, you have a daunting task if you don't have the proper tools and technology.

Bursting, a technology that has recently become available, provides an alternative to streaming. It provides some network bandwidth management tools and leverages inexpensive client storage to optimize and reduce the load on the network. With streaming, to ensure that video demand is met, IT managers need to reserve enough video bandwidth plus overhead to meet the worst-case peak demand, and that can be wasteful. Whether you are bursting or streaming, if you are sending high quality audio or video over a network, you have to manage your network resources wisely.

Here are some of the questions IT managers should ask themselves about enterprise-level delivery of video over networks.

How robust does my network need to be to handle video?

Video streaming is only as strong as its weakest link. If your servers, routers, switches, etc. are 100% reliable and have limitless capacity, then they should stand up well to streaming. But because of streaming's real-time nature, any network hiccup is reflected by glitches, jitters and interrupted or failed delivery to the desktop. Will viewers tolerate this or is their level of expectation higher?

How good does the image need to be?

With all due respect, if the video of the CEO is a bit fuzzy or jittery, it won't interfere with the message he or she is delivering and streaming should work just fine. The picture will be adequate and the audio will probably be clear. But if you are delivering an instructional video with highly detailed content, you'll want the highest resolution and steadiest picture. Right now, streaming won't give you a full screen of high resolution video because many networks do not have bandwidth to deliver such video to enough viewers simultaneously.

How do I ensure more consistent video delivery?

One way is to reserve enough bandwidth in anticipation of peak demands. But that can be prohibitively expensive. Another way is to turn storage into bandwidth through bursting. Local storage, such as memory and disks, is getting cheaper and cheaper. For example, Burstware® from Instant Video Technologies, www.burst.com, takes advantage of this trend. When network demand is low and there is available bandwidth, Burstware® gathers the video into chunks, or bursts, and delivers them over the network faster than they can be viewed. The video data is stored at the viewer's desktop. The viewer then spools the video off the local storage. If demands on the network rise and available bandwidth decreases, the viewer just plays from the local cache, decreasing the demand on the network. And if the originating server goes down, another server can take over and continue delivering the rest of the video to the cache at the receiving end. The user, watching the video being played from the local cache, will not see any interruption.

Should I work with video compressed in different formats?

A variety of media file formats have appeared in the last few years. Each have their drawbacks and advantages, depending on how much bandwidth is available and how good the video must look and sound. You probably don't want to be restricted to one format. Make sure the video delivery system can deliver and play video encoded in a variety of formats.

How do I manage my network load and still accommodate the demands of viewers in my enterprise?

The answers come in switching technologies and in management policies. There are times of the day that demands on the network are at their peak--say, between 8:30am and 9:30am when everyone is checking their e-mail for the first time of the day. One management method is to simply not schedule video delivery for that period of time. Another solution is to tell the video delivery management software how much bandwidth it can use. It should be able to manage the various loads for you. As other demands for bandwidth increase, video delivery can be restricted.

My enterprise is changing all the time and adding new clients. How can I handle a growing number of viewers?

You want to look for a scalable solution that makes it easy to deploy more video. The delivery system should make it easy to add more servers and clients by intelligently managing the new load. Clients should be automatically routed to new servers, servers should automatically figure out the most efficient way to handle new clients.

Will video figure in the Internet?

Today, bandwidth limits and bottlenecks on the Internet prevent delivery of video that meets most users' standards. But the growth of broadband communications means video bursting will soon be usable by more consumers both on and off the Internet. Even today, for many enterprises combining LANs and high-speed WANs, IT managers already have enough bandwidth to consider a number of video delivery options. Most likely they will choose the one that helps them deliver the best picture and sound while optimizing the load on the network.

In conclusion, there are numerous options for video delivery over networks. Look at the big picture--literally. Make use of two major industry trends: Increasing bandwidth and the plummeting price of mass storage and apply them to your future plans to leverage video on your WAN, LAN, intranet or the Internet. Choose a total technology solution that will optimize your network bandwidth, make your content look its best, and give you the tools to manage your infrastructure and simultaneously satisfy the pickiest video demands of your audience.