Streaming media extends a company's ability to communicate internally and externally, and it enables access to content that's focused on both general business and industry-specific information and issues. As such, live and recorded audio and video streams present a significant opportunity for your enterprise.
Streaming-media technology first came into being during the mid-1990s, with product offerings from vendors such as TrueSpeech, VDOnet and Progressive Networks (now known as RealNetworks). The early products were very limited; among these vendors, only VDOnet offered streaming video, with TrueSpeech and Progressive offering streaming-audio products. Quality was clearly an issue.
Streaming technology has evolved rapidly, and streaming-media vendors now support near-VHS-quality streaming video at reasonable bandwidths (hundreds of kilobits per second). As a result, more and more Web users are accessing streaming-audio and -video files. A survey by Nielsen//NetRatings shows that 35 million users accessed streaming content from home in November 2000 -- a 65 percent increase over the same period in 1999, and a figure that represents about 36 percent of all Web users (see "Streaming Media Percent Growth and Reach."). Meanwhile, three companies are vying for status as top streaming-media technology provider: Apple Computer, Microsoft Corp. and RealNetworks.
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Internet and enterprise network infrastructure also has evolved to more effectively support the demands of real-time streaming. It is entirely possible to ensure a quality streaming-media deployment across the corporate intranet without disrupting mission-critical client/server applications. Streaming media on the Internet, meanwhile, is still far from perfect; narrowband connections and congestion continue to cause substandard results. However, manufacturers and service providers have developed and implemented technologies such as splitting, caching and application-level multicasting that provide greater assurances of successful streaming on the Internet, even when serving large audiences.
Enterprise Applications
There are many ways to deploy streaming media as a strategic tool for your enterprise. Internally, streaming media is often used for corporate communications, training, product launches and e-learning. Combining streaming and Web technologies -- for example, accompanying video or audio streams with slide shows or chat -- yields a powerful experience. Likewise, today's simple streaming-media development tools make end-user and departmental streaming applications relatively easy to create. Other possibilities, such as security monitoring and virtual panel discussions, also exist.
External applications often have a consumer focus; examples are customer training, sales support and customer service. Streaming media is an excellent tool for reaching other external constituents as well. For instance, live Webcasts are becoming commonplace as part of the corporate investor-relations effort. Additional enterprise applications may relate to specific vertical markets and B2B activity. Building community and sharing special-interest information and content are strengths of the Internet in general, and of streaming media in particular.
When you consider prospective applications, don't restrict yourself to the applications you hear or read about. Streaming technology is useful in any instance where the use of real-time media such as video and audio can overcome barriers of distance and time to deliver some value to your enterprise. Thinking out of the box is in order. Remember, this technology can provide a competitive advantage for your company if you play your cards wisely and find the right application in the right setting at the right time.
When deploying streaming-media technology internally, you must address some significant issues. One is bandwidth consumption. This is often a problem in unicast streaming, which is definitely the easiest transmission mode to implement. Bandwidth management, network provisioning, multicasting and splitting all offer possible answers to the bandwidth challenge. Careful consideration of the trade-offs involved with these alternatives is necessary.
Another issue is audio/video quality. While this is a function of bandwidth, audio and video production is another important factor in the quality equation. Of course, anyone can set up a microphone and a camcorder and Webcast a video, but achieving a quality broadcast is an art. The skills you've developed as an IT professional are very different from those you need to produce quality audio and video. And this is complicated by the fact that video production for streaming media is quite different from video production for conventional media. Typically, we're talking about small frames, in which any embedded text is unreadable, panning and zooming are problematic, and wide shots are useless.
If you're considering an external application via Internet streaming, you'll need to take into account Internet realities such as narrowband connections and a lack of QoS (Quality of Service). Congestion and traffic control aren't huge issues if you want to reach just a moderate-size audience, assuming your network provider has an infrastructure that can handle the spikes in traffic that can occur. But if you have aspirations to deploy streaming as a mass medium to reach many eyes, be aware that this scalability for the masses is still an uphill battle.
A Victoria's Secret fashion show a couple of years ago was the poster event for this problem: Demand swamped the site, and thousands of prospective viewers were unable to view the high-profile Internet streaming event. Recently, a live Madonna Webcast was more successful. If the commentary on "thelist" (a streaming-media industry mailing list maintained by Streamingmedia.com) is any indication, however, this event was far from a total success, as many prospective Internet viewers had difficulty obtaining and maintaining a live stream for the duration of the event. We suggest you set some limits on your ambitions for scaling up live events to serve many users.
How It Works
Regardless of how you plan to apply streaming media, you'll need a thorough understanding of the technology to make the right decisions about which products to use, how to optimize bandwidth and when to turn the whole operation over to dedicated professionals.
The core concept of streaming media is buffered play. A desktop streaming-media software player establishes a connection with a streaming-media server and requests a stream. The server begins to stream the media to the player, and the player receives that stream and buffers several seconds' worth of data on the client computer's hard drive. A brief glitch in stream transmission due to network congestion won't affect the quality of the media playback as long as the buffer still contains data.
Streaming servers can provide continuous access to stored media files in an on-demand fashion. Or, a live event can be "captured" on a computer with audio- and video-capture cards, and streamed in real time -- this is a Webcast. Corporate Webcasts are often integrated with additional capabilities for some sort of interaction -- for example, the ability to submit questions to a talking-head presenter. Servers can also be used to stream a stored media file in a simulated "live" broadcast mode, to create the impression of a live event, which may attract prospective viewers.
Unicast, Multicast and Splitting
The most common streaming-media transmission mode is unicast streaming, which is always used when streaming on-demand content. The streaming server establishes a separate unicast stream for each client requesting access to the media, enabling any user to access any on-demand media source at any time. A problem with unicast streaming arises when many users concurrently access streaming media from the same server source, as the overall bandwidth requirements are additive. Unicast streaming allocates bandwidth to each end user.
Multicast streaming is an alternative transmission mode in which a single real-time stream services many users concurrently (see "The Wizardry of Multicast"). Because multicasting requires much less bandwidth than unicasting, this mode is sometimes used for live events. Multicast streaming is also efficient for delivering concurrent access to a very popular static media file (say, streaming the pre-recorded CEO address that everyone in the enterprise must see).
Multicast transmission requires diligent network management. You have to be very careful about how routers are configured along the path, and you can't assume that multicasting will work if the network has not been specifically designed to support it. Internet multicasting, meanwhile, is possible only on the specific portions of the Internet that are directly controlled by a service provider, such as UUNet, that has enabled such transmissions. Alternatively, you can use the M-Bone, a virtual multicast network that uses tunneling to interconnect routers configured for multicast transmission. In the enterprise, network administrators can work to ensure a multicast-enabled intranet, though that can be a significant challenge in a large enterprise.
Another popular alternative for bandwidth conservation is called splitting. This streaming technology is useful in the enterprise for conserving bandwidth over WAN connections, and it is also used on the public Internet by content-management companies such as Akamai Technologies and Digital Island. Splitting involves setting up a source-media server, where you're originating a Webcast, along with multiple splitting servers in other locations. You then split a stream from the source server to each splitting server, where it is rebroadcast to users of that server. In the enterprise, a typical scenario would be a source server in one corporate location that originates a broadcast and transmits that stream across WAN links to other corporate locations, where splitting servers receive the source stream and rebroadcast it to local clients. WAN bandwidth is conserved, since only a small number of streams traverse the WAN to the splitting servers in remote locations.
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