Speeds Explained

By: Richard Lowe

So how fast is your internet connection anyway? Yeah, I know
that many companies now (especially DSL - for more information see
http://www.internet-tips.net/System/DSL.htm, and cable) are advertising
speeds of upwards of a megabit or more. Well, what does that really mean?
And how fast is 56K or 28.8 anyway?

I know this is hard to believe if you're relatively new to the world of
computers or the internet, but back in 1978 modems were running at 110 or
300 bits per second (the technical term is baud). The table below is not
precisely accurate but gives a rough idea of how the speeds have been
working their way upwards for the past few years.

Speed Timeline

1978 100 to 300 baud
1988 1200 to 2400 baud
1993 14,400 baud
1995 28,800 baud
1997 33,000 baud
1998 56,000 baud
1999 1,500,000 baud DSL and cable mode connections

In comparison, local network connections run at 10,000,000 bits per second
at least and it is becoming more common for these to be running at 100
million bits per second.

But what does all this mean? Well, a character is eight bits (a bit is a
zero or a one, and it takes 8 of them to make a single character). The
letter K means 1,024, so a 28K modem is 1,024 times 28 or 28,672 bits per
second (also called bps).

Now divide the 28,672 by 8 and you have the maximum number of characters per
second that your modem can run at.

This works out to 3,584 characters per
second, which in today's world is considered pretty slow (you will
understand why shortly).

Interesting fact: Modem speeds are all standardized by International
Telecommunications Union (ITU). The ITU defines 28.8K bps modems as v.32 and
33.6K bps modems as v.34.

All right, now you are getting 3.5 thousand characters per second, if you
have a 28K modem, right? Well, not exactly. First off, the quality of your
phone line may drop that down significantly. What happens is your computer
sends some data to the "internet"; it is received but there was an error, so
the internet computer requests that the data be resent. The worse the
quality (you can hear how bad it is by the amount of static you can hear
when you listen on the line) the more times the data has to be resent, the
slower the line.

On top of that, there is a certain amount of overhead associated with each
connection. This is "handshaking", which means the modem is asking the
internet computer if it got the data and the internet computer is responding
"yes" or "no". There is also a certain amount of data to define what is
being sent (an email or a web document or whatever) which eats into the line
speed.

Well, okay, let's assume you are actually getting 20K from your 28.8K modem.
There's worse news to come. The internet has lots of things that actually
have nothing to do with content. There are cookies
(http://www.internet-tips.net/Security/cookies.htm), advertising banners,
comments, web bugs (http://www.internet-tips.net/Security/webbugs.htm), and
a host of other things inserted into your web experience. A typical
advertising banner is 7.5K, which in our 20Kbps example requires several
seconds to load to your machine.

What can you do? FirstFree Web Content, if you can get a DSL or Cable modem connection to
the internet. It will probably cost about the same or only slightly more
than your dialup connection and will improve your surfing experience by many
times.

Second (or if you cannot get a higher speed connection) get an ad blocker
(http://www.internet-tips.net/Security/adblocking.htm) installed on your
system to remove those ads before they are downloaded to your machine. Why
even bother downloading banners that you are never going to look at anyway?

I hope that helps clear things up a bit.

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