How
Streaming Works,
And Why Not Do It Yourself?
A
Simple Analogy
Lets
say you are giving a concert on your own private island.
The island connects to the mainland by a narrow footbridge.
When the concert starts, only as many people that can make
it across the footbridge can get onto the island to hear
the concert. Without pushing that analogy too far, thats
the general idea. You have a narrow network pipe going to
your home or business, and that pipe will only accommodate
a small number of simultaneous visitors. The solution is
to transmit your material to SurferNETWORK and let your
visitors listen or view your material from our data center
(where we have a gargantuan network pipe).
Doing
It Yourself
To
be a bit more scientific about it, lets say that your Internet
connection is by DSL, Cable modem, or T1. DSL and Cable
modem services are typically provided to residences for
about $50/month. T1 is the standard service offering for
businesses, and typically costs $600-800 a month. T1 normally
is 1.5Mbps (Mega bits per second) in both directions. DSL
and cable, on the other hand, are asymmetric, having a much
greater capacity when you download material compared to
when you send material. Both services commonly offer about
the same download speed as a T1, but only a small fraction
of that speed in the upload (sending) direction. If visitors
connect to your web site across one of these links, the
number of visitors who can connect is limited by your upload
speed (you are uploading to them). Lets say, for example,
that your upload speed is 256,000 bits per second. And,
lets say that you are playing a standard data rate video
connection of 100 kbps (kilo bits per second). 100 kbps
is 100,000 bits per second, your capacity is 256,000 bits
per second, and therefore, only two visitors can connect
at the same time. If you were playing audio at 30,000 bps
then the theoretical maximum number of concurrent listeners
is about eight. But from a practical aspect you can never
reach anywhere close to the theoretical maximum. You might
actually only be able to support four or five concurrent
listeners.
Its
a bit better on a corporate T1, but the same rules apply.
And heres the rule: take half the upload speed of your
network connection, add ten percent overhead to the data
rate of your material, and then divide your net upload speed
by the data rate plus overhead. Therefore, a T1 will support
at best about 7 concurrent viewers or about twenty concurrent
listeners. But, that completely maxes out your line, so
if the line is used for any other purpose you risk stalling
or stopping that other traffic. Conversely, any other traffic
on the line diminishes your media carrying capacity.
An
even greater problem is that you cant control how many
visitors will come at once, and if too many come at the
same time, everyone gets a bad experience. Packets collide,
get delayed or dropped, and the visitors players start
to rebuffer. Eventually, as your line gets above 50%
capacity, all of your visitors get jerky, interrupted feeds
with constant rebuffering. And, you dont know. There isnt
any ready way for you to tell whether they are getting a
perfect and enjoyable listening or viewing experience, or
an unpleasant one.
Of
course, you can get higher speed circuits than T1 lines,
but for thousands of dollars a month. And, even if you did,
you still have the same type of limits. If you advertised
your concert and attracted many visitors, all of them would
get a bad experience.
The
Better Way
The
better way is to provide us with your material, either by
providing files to us, of connecting a single upload feed
from you to our data center. When visitors to your web site
click to access media content, they are redirected to us
(they dont know it). Because we sit on the Internet backbone
(the Internet superhighway), we can support many thousands
of concurrent listeners or viewers. In fact, whereas, for
example, a T1 connection provides a data rate of 1,544,000
bits per second, our data center servers have a capacity
of multiple times 1,000,000,000,000 bits per second (and
if we wanted or needed more, there is virtually no limit
on the amount of network capacity available to us.
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