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Bandwidth Basics - A Comparison of Connection Speeds
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Common Phone Modem (28.8)
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28.8K
(28,800 bps, bits per second) |
Typical modems marked as 28.8 or 33.6 use phone
lines without compression. This is usually enough for surfing the web, e-mail etc.
Surprisingly to many, we have successfully run Internet proxy networks with 5 PCs sharing
the same 24,400 connection. |
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Common Phone Modem (56K/x2)
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56K
(56,000 bps) |
This modem uses data compression to squeeze more
out of the common phone line (made to support 24,000 to 28,000 max). If your ISP doesn't
support 56K compression technology, you will not achieve this mark. In fact, most business offices can not enjoy much more than 26,000
speeds. It seems that Ma Bell gave greater preference to residential lines when service
centers were installed. Over the past 5 years we were surprised to have encountered one
lady really connecting at 54,400 from her new home. [Don't believe you dial-up
monitorwhen it states "connected at 64,000"] |
Test My Modem Speed |
ISDN Line (Integrated Services Digital Network)
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128K
(Basic Rate -128,000 bps)1.54Mbs
(Primary Rate - 1,540,000 bps) |
Phone companies love to dish out this service to
businesses that rely on video-conferencing or downloading large files. Why? Because ISDN
is so expensive - expect to pay from $.05 per minute to $270 a month for unlimited use. Using your analog line, ISDN carries voice and data over the same
line by sharing two channels A and B (a third channel, D, carries the call set-up info).
One hitch: if you use the phone, one channel drops, leaving you with 64K.
Primary Rate ISDN is the same technology, but it uses 24
channels. |
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IDSL
(Integrated Digital Subscriber Line)
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128K
(128,000 bps) |
This is a neat flavor of DSL, which is circuited
for users too far from the phone company's area service hub. It is dedicated, always
on, and download speeds equal upload speeds (you get stuff and send stuff at the same
rate). You will get your own IP (Internet) address, which can be used for remote
access. You don't need to add another line, just use the copper already in place. You will
buy a special router or hub modem (a box), which converts the signal for your computer
network. The rates differ from provider to provider, but are much more affordable than T-1
or ISDN. |
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ADSL
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128,000 bps - 2.5Mbs |
Upload and download rates may differ from plan
to plan, as the proximity to the service hub is the key factor. Some providers provide an
SDSL service that is shared among several customers. Other DSL services advertise security
on Real or Virtual Private Networks that they manage with your dedicated line.
That's nice, but you can do this on your own using the Point to Point Tunneling Protocol.
DSL is hot right now, and residential users close to the hub can get great service,
inexpensively. |
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T-1
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1.54 Mbs
(1,540,000 bps) |
This is what large companies use for
dedicated, large networks, information servers or Web site hosting. It's
expensive, about $1,000 a month, but very available. You would use this if you had a
professional, on-site IT staff who would set up Frame Relays for your many users.
See your phone company for details. |
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T-3
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45 MBs
(45,000,000 bps) |
Bigger than the T-1, it is used for professional
web site hosting, superheavy data systems and requires dedicated support. See your phone
company for details. |
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Worwetz
E Systems