Local Heroes: Solutions for LAN- and WAN-based Streaming (Part 1)
Ever get the feeling all your streaming problems would be solved if only your streams were limited to a local area network (LAN)? Video streaming on a LAN looks great, primarily because you can encode at the 100-300Kbps necessary for good quality without ruffling the feathers of any IT types. After all, even 10 simultaneous streams of 300Kbps video consumes only about 3% of the total network bandwidth on a 100Mbps LAN (aka 100 Base-T), or an unnoticeable .3% on a Gigabit network.
Send the same 300Kbps video stream to a remote office over the wide area network (WAN) and you’ll shut down a 256Kbps link and put a serious hurt on a T1 link that runs at 1.54Mbps. Clearly, managing video over LAN and WAN are two completely different tasks, and the latter’s obviously much more complex.
Intuitively, it feels like the solution involves pushing the video files out to the remote networks and playing the high bit-rate files from there. If you’re running Microsoft servers at each location, and streaming only Windows Media audio and video, this certainly can be cost-effective, since Windows 2000 and 2003 servers all include Windows Media Servers at no extra charge.
Sounds simple enough, but Windows Media Servers have no built-in capabilities for automatically distributing video files over a WAN. Manually distributing the files (during off-peak hours, of course) and managing the Web page links that direct employees to the right content would be a Herculean task, even for organizations with only moderate streaming usage. In addition, this does little to serve other potential consumers of the video—like clients, distributors, or employees working from home—and it does nothing for formats other than Windows Media.
For these and many other reasons, manually managing multiple media servers—Windows Media or otherwise—is almost certainly not the way to go. This much is clear.
What’s also clear is that, given the disparity of requirements between different organizations, there is no one-size-fits-all solution. There are, however, questions you should definitely ask when considering technologies for efficiently distributing video and other rich media over a WAN.
To help illuminate these, we analyzed three different technologies. By no means is this an exhaustive survey, but they represent a cross-section of available solutions. First, we’ll introduce you to the technologies and companies that provide them, then we’ll identify the questions you should consider when selecting a company and technology. (Sometimes, you’ll find that a single technology isn’t enough to meet your needs; see the sidebar at the end of this article on the Cisco Business Video Solution for an example of a custom, multi-vendor approach.)
Before we start, however, let’s set up the problem we asked each vendor to solve. We assumed a small company with four offices, each with a 100Mbps LAN with a Windows 2003 Server. Offices were connected via T1 lines and the total number of computers served was 200. Most video content was produced at 200Kbps at the main office and viewed by computers on all four LANs. The obvious issue is how to distribute the content from the main office without swamping the T1 lines.
Companies and Suppliers Mentioned