|
Get
connected
The second in our
series of articles about technology tools for distributors explains
how to get connected to the Internet.
by Akarin
Weatherford
You often hear the
word bandwidth during discussions of
interconnectivity. Ask someone to explain what bandwidth is and how it
relates to your company, and you’ll get an answer that brings you to
their level of confusion. Here’s a simple analogy to straighten
things out.
Think of bandwidth as
the number of lanes on a highway. The cars on the highway represent
all the data you are trying to move.
If you have 100 cars, will a two-lane or a 10-lane highway get them
from Point A to Point B in the least amount of time? The answer, of
course, is the 10-lane highway. The wider the highway (bandwidth), the
quicker we can move more cars (data) from Point A to Point B.
Bandwidth is usually
measured in “bps,” or how many “bits per second” we can push
through the connection. Metric modifiers like “Kilo”
(K = 103) or “Mega” (M = 106) are often added to help quantify the
speed. So, 56 Kbps = 56,000 bps and 1.5 Mbps = 1.5 million bps.
It’s pretty
confusing sometimes to try to
figure out all the options available to you for
connecting to the Internet. We are going to touch on the most common
connection options and give you a heads up on speeds and general
pricing.
Modem dial-up
Modem dial-up access
is the most common and affordable way to connect to the Internet. It
is also one of the slowest methods and usually connects only one PC at
a time. Modems connect computers to the Internet by performing a
digital-to-analog conversion for transmission onto the phone lines and
vice versa on the receiving end. Most modems support a
maximum speed of 56 Kbps, but rarely connect at that speed because of
phone line limitations. A modem also ties up your
phone line, so you may need another line if you want to receive
calls simultaneously. Dial-up access is “on demand,” so you have
to proactively access the Internet. You can expect to pay up to $20 a
month for this service.
Cable access
Cable access is
relatively new. It is one of the broadband
technologies opening high-speed Internet access anywhere cable
television is available. Cable access is a digital signal sent over
the unused channels on the existing cable TV in your home or office.
Using the highway
analogy, cable TV has always been a 10-lane highway. To give you 100
channels of TV programming, cable TV used only about two of the 10
lanes. Internet access is just one of the many services on the unused
bandwidth. You can expect speeds of 256 Kbps to 6 Mbps depending on
the services offered by the cable company.
Cable access is
“always on,” meaning your phone lines are
available and you never have to do anything to connect to the
Internet. One drawback is that you share your connection with everyone
on your block who subscribes to the same service. You basically share
the cable
company’s LAN (Local Area Network) with other customers, which is
why they don’t usually
guarantee the maximum speed you purchase. Therefore, at peak hours,
the bandwidth may become saturated (traffic jam on the highway), plus
there are security concerns about your neighbors “peeking in” on
your data. Cable access is available for home or office with prices
starting around $40 per month for home and around $80 per month for
office.
DSL (Digital
Subscriber Line)
DSL is a service
offered by a phone
company. It uses the existing copper in your building to provide
high-speed Internet access and is a direct competitor with cable
access. DSL uses digital
signals over phone lines but also gives you the ability to use analog
phones simultaneously with the addition of a small adapter box. DSL is
always on like cable and has varying speeds from 144 Kbps up to 1.5
Mbps. However, DSL is only available in metropolitan business areas
due to the special conditioning the phone company must do to its lines
and equipment behind the scenes. DSL is
quickly becoming more competitively priced with cable access. Prices
range from $50 per month to $100 per month for
basic services.
Integrated Services
Digital Network (ISDN)
ISDN is the
long-standing, digital voice and data service
traditionally made available to small businesses by phone
companies. ISDN uses regular phone lines but requires a network
termination device in your office to connect a limited number of ISDN
devices (phones, terminals, alarms, network devices, etc.). ISDN is
sold in 64 Kbps channels and is still an expensive alternative at
about $60 per channel per month.
Leased lines
Leased lines are the
top dogs when it comes to Internet access. The most common leased line
is a T-1 (1.544 Mbps). A T-1 can be broken up into smaller, more
affordable fractions or multiplexed with other T-1s to create a T-2
(6.3 Mbps), a T-3 (5 Mbps), a T-4 (274 Mbps), and so on. A T-1 is a
digital signal that operates over a standard, copper cable. The
benefits of having a leased line are in security and control. With a
leased line, the full bandwidth is
dedicated to you directly from your office to the Internet. Also,
you have complete control over the use of that bandwidth. When hosting
Web sites and Web applications, this is the preferred method. Prices
range from $500 to $1,500 per month for T-1
connections depending on selected service options.
Wireless
There are many
options when it comes to connecting wirelessly to the Internet.
Offices use satellite, microwave or RF (radio
frequency) to get Internet connectivity in remote locations.
Individuals use one of many flavors of analog or digital cellular
connections. There is such a broad array of technologies and
costs that this topic deserves its own dedicated article. Just
understand for now that, in general, affordable wireless data rates
are very slow — 14.4 Kbps to 19.2 Kbps over cellular costs normal
cellular per-minute charges; a T-1 transponder on an Intelsat
satellite will cost you about $15,000 per month.
So, let’s do a
little speed comparison. Suppose a manufacturer’s Web site has a
product manual written with Microsoft Word that contains various
tables, graphs and highly detailed images of the product. The file
size is 1.44 Megabytes (the same size as the capacity of a floppy
diskette). An average Word document is
normally under 100 Kilobytes, but the graphs and images make this a
pretty beefy document. Let’s assume that the manufacturer’s Web
site always has a greater connection speed than your own. Compare the
download times in the table above right. (If your calculations don’t
turn out right, read “Watch your B and B’s.”)
Why are some
connections
so slow and expensive?
If two computers in
your office are networked together at 100 Mbps (the most common office
network speed), and it cost you under $100 at the office supply store
to buy the parts to hook them together, why does an ISP charge $1,000
a month for a T-1
(1.5 Mbps), which is 10 times the cost at 1/15th the speed?
The basic reason is
because of various limitations on the
technology. You see, a LAN has a known worst-case distance between
computers, usually covering up to a square mile. Because of this
assumption, all sorts of inexpensive hardware and
software methods can be used to boost accurate and blazingly fast
performance. When dealing with a WAN (Wide Area Network),
the worst-case distance between computers is unknown and
specialized hardware and software methods must be used to
provide reliable connections.
Hooking up the
plumbing
“You’re only as
strong as your weakest link” applies to Internet connections with a
slight twist: “You’re only as fast as your slowest connection.”
Here’s an example.
Office A’s LAN is
100 Mbps and connects to the Internet via
a 256 Kbps ISDN connection. Office B’s LAN is 100 Mbps and
connects to the Internet via a 1.544 Mbps T-1. The fastest data
transfer rate between Office A and Office B is 256 Kbps because that
is the slowest connection in the chain. It is important to identify
and understand where the bottleneck in bandwidth exists. You may not
need to invest big dollars in the latest, greatest network equipment
if you can’t take advantage of its features because of your network
connection speed to the Internet.
Watch your B and
B’s
Now you’re armed
and dangerous with the basic knowledge of various connection types and
speeds to the Internet. Here’s one “gotcha” that gets a lot of
people, even your long-haired IT guys if they’re not paying
attention. There is a little math here, but if you get this, you’ll
keep from looking like a goof when it comes up.
Let’s say you just
got that high-speed T-1 connection in your office (remember, that’s
1.544 Mbps). You begin to download a
document off the Web from Yahoo!, which has a “fat pipe” on the
Internet (they have a whole lot of bandwidth). A little window pops up
showing your download progress and the download speed. You notice the
speed is 75 KBps and think to yourself, “75 K? I have 1,544 K (1.544
M) connecting me to big bad Yahoo!, so why is it downloading so slow
at 1/20th the speed of my T-1?”
Actually, it’s not.
Pay attention to the size of that “B.” Notice that we have been
talking about connection speeds in “bps” or “bits
per second.” The download box you see uses “Bps” or “Bytes per
second.” For anyone geeky enough, you know there are eight bits in
one Byte, and 1 Kilobyte = 210 Bytes or 1,024 Bytes (because of the
binary to decimal conversion). For the rest of the normal world,
we’ll just say there’s a crude and rough 10X difference between a
bit (b) and a Byte (B). So, doing a quick conversion on the above
statement, 75 KBps converts to 750 bps, which is about half your full
T-1 connection speed (the exact value is 614.4 KB). So, in
reality, you’re moving really fast!
Akarin
Weatherford
is chief
technology officer and responsible for the e-business development
practice at Indian River Consulting Group (IRCG), an experience- based
firm specializing in distribution. Started in 1987 by J. Michael
Marks, IRCG has specialists who consult with distributors and
suppliers to make the changes necessary to maintain competitive
advantage. Weatherford is available as a speaker on technology issues
within the
distribution industry. Contact him at 321-956-8617, or visit
www.ircg.com for more information.
This article originally appeared in the
March/April 2002 issue of
Progressive Distributor. Copyright 2002.
back to top
back
to e-business archives |