A S t r e a m i n g M e d i a P r i m e r :
H O W D O I P U T M Y S T R E A M I N G M E D I A O N T H E W E B ?
If your fi les are MBR (multiple bit rate) encoded, use the above equation for each stream
contained in every MBR fi le. Add the results of your calculations for all of your stream
If you're delivering a lot
ing media fi les together, then don't forget to add the amount of storage you need for the
of streaming content over the
server software itself, and whatever incremental capacity you anticipate needing.
What about my Internet connection?
bandwidth is typically the major
Perhaps surprisingly, the capacity of the streaming server is not typically the limiting
factor for throughput the bandwidth of your Internet connection is what really counts.
expense. Leasing costs for the
A single Macintosh running QuickTime Streaming Server can deliver up to 1,000
high bandwidth digital lines
simultaneous streams at 56 kilobits each, or an aggregate of over 50 megabits per second.
you need can cost more per
That's enough to saturate 40 T1 connections to the Internet, or to completely swamp
fi ve 10Base T Ethernet LANs.
week than your server and
But the good news is that you only need enough bandwidth to accommodate the
software cost annually.
amount of streaming you plan to do To serve a small number of streams from
Setting up a Streaming Server
your home or offi ce, 128K DSL is the minimum you should consider. Cable modem
can be used, but continual traffi c fl uctuations make the network unreliable, potentially
compromising the quality of your streams. In fact, attempting a live Webcast over a cable
modem connection would be unwise. A single T1 line can carry enough streaming data
to serve 25 end users simultaneously connected at 56K. Whatever your connection, be sure to check
with your ISP your throughput will be limited by your ISPs backbone carrier; some ISPs are better
prepared for the anticipated explosion of streaming media demand than others.
So just how much bandwidth do you need? Let's use a bit more bandwidth math to fi gure it out
the bandwidth required for serving content can be calculated by multiplying the data rate (in kilobits
per second) of your streaming production(s) by the maximum number of simultaneous streams
you expect to serve:
Kbps X maximum number of simultaneous streams = Kbps of bandwidth needed
Example bandwidth calculations
Data rate of streams
Max. audience size
1,200 Kbps or 1.2 Mbps
60% 20 Kbps plus
4,400 Kbps or 4.4 Mbps
40% 80 Kbps
8,000 Kbps or 8 Mbps
10 Mbps fractional T3
40,000 Kbps or 40 Mbps
Enough math already! I just want to make streaming media
We've got good news for you... If you don't want to mess around with servers, you don't have to. Just as
there are Web hosting providers, there are hosting services that can serve your streaming media fi les for
you. Should you serve your own streaming media or outsource?
Defi ne your target audience: Are they dial up or broadband customers? Is your
content video, audio or both? Live or on demand? Is your content mission critical?
How much redundancy do you require? Do you require support or do you have
the expertise to run the hardware and software? Do you want yourself or someone
else to take the page at 3am when the service is down?
50 QuickTime for the Web, by Steven W. Gulie, May 1, 2000, Morgan Kaufmann Publishers
52 Choosing a Hosting Provider, by Steve Stevenson, http://www.streamingmedia.com/tutorials/view.asp?tutorial_id=52