Nina Wishbow
Network Appliance

Need to show John Cleese’s management training videos to your corporation’s management team, but can’t get everyone in a room at the same time? New technologies are allowing corporate intranet and Internet users to access documents, videos, and other e-learning materials across large distances. These new technologies are called Content Delivery Networks (CDNs).

A CDN is a network that consists of a traditional intranet or Internet, specialized devices for storage and caching, and applications for distributing content to different parts of the network. The key to a CDN is placement of rich data at the “edge” of the network, far from the central servers and close to the people who are accessing the data. By putting content close to the user, before the user requests it, there is less interaction between the user’s browser and the central Web server. This reduces access times, network traffic, and the server’s load, resulting in better delivery of the content. The technology that sits at the “edge” of the network can be a conventional file server, but special-purpose caching appliances also provide this function with less administrative overhead.

The CDN becomes even more effective when specialized devices called filers are linked to the central server. Filers can efficiently store multiple terabytes of data and can quickly serve this data when required. To illustrate how a CDN might be deployed, think of a corporate training center in Houston with offices in New York, Los Angeles, and Tokyo. In Houston, filers store vast amounts of content, the content is “pushed” to remote caches, and the caches in each of the remote locations deliver the content locally. In addition to efficient handling of data, the caching devices ensure high quality of delivery (especially for video), dependable service, and support for many media formats.

Network Appliance customers have implemented content delivery networks for a variety of reasons, including:

  • Live and on-demand video broadcasts of corporate events
  • Live and on-demand video broadcasts of training
  • Distribution of documents (reports, presentations, engineering files)

At Network Appliance, we use our own equipment in our internal content delivery network. Network Appliance sells filers, caching appliances, and content distribution applications, and we use our products to deliver documents, video, and other media.

In the Technical Publications department at Network Appliance, we’ve taken advantage of our own technology many times. Recently, we rented a series of training videos. To view the videos, we could have required all of the viewers to gather together for several hours. Given that it’s hard to get people together for a one-hour meeting, let alone several hours of training, we streamed the videos. (Streaming is the technical term for serving video data over a network.) People were able to watch the videos in 20-minute segments from their desks whenever they had the time. The quality was very crisp (no “Max Headroom” effect), and, because it was easy to take in the content over several days, everyone who needed the training was able to receive it. Even more recently, some writers were too busy to attend the corporate All Hands meeting, so they watched the live presentations from a corner of their monitors while they worked to meet their deadlines. In fact, people in remote Network Appliance offices always watch corporate presentations online, either in real time or after the fact.

Content delivery using filers, caches, and distribution tools offers several advantages over traditional Internets, including:

  • Reduced network traffic to central servers
  • Lower administration costs
  • Specialized software for backups, mirroring, and scheduled movement of content from one part of the network to another
  • High availability
  • Short access times

As more content, particularly streaming media, is delivered over Internets and intranets, content delivery networks will play a larger role in organizations responsible for providing the content.