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The
telecommunications needs of a business or a family can be met by anything from an occasional visit to a phone booth,
to a megadollar globe-spanning network with satellites, fiber-optics and folks in white
coats to maintain it.
Here are
your main options:
One or some single-line
phones, ordinary or feature-laden, probably tethered to a wall jack and
perhaps to a computer. It might be a cordless phone, or cellular, and might be combined
with something to answer calls in your absence. Probably OK for a one-person office, or a
small retail store.
A
single-line-telephone is called an SLT.
Basic services from the phone company are called POTS,
for Plain Old Telephone Service.
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| One or some multi-line phones
(2 or 3 or 4 lines), that plug into wall jacks -- or could be cordless -- and don't
have intercom or other interactive features, and don't require a big box on the wall to
make them work. Put one person on hold while you talk to someone else. For the company
that needs a bit more than an SLT |
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| Several multi-line phones that do interact with each other, with features such as intercom, paging and call transfer, and don't
require a big box on the wall to make them work. A group of interacting multi-line phones is called a key system, and that box is called a Key Service Unit, or KSU; so a phone system that doesn't need one is called a KSU-less key system.
Available with 2 to 4 lines, and up to several dozen phones. Lots of new models use cordless phones, and you can install a sophisticated system in a few minutes. |
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| Several interacting multi-line phones with a KSU on the wall, a key system -- the traditional small business choice, with a great range of features. Suitable for companies with a couple of
employees, and up to about 150. |
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| Several interacting single-line phones (or perhaps
multi-line phones) connected to a different kind of box, or a circuit board in a computer, and known as a PBX system -- the present incarnation of the traditional office switchboard with plug-in cords. Usually used by companies with staffs from about 50 people, up to many thousands. |
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The most obvious characteristic of a modern non-cord PBX system, is that you dial the number 9 to get a dialtone to make an outside call. PBX is the abbreviation for Private Branch Exchange.
Non-cord PBX systems are sometimes called PABX (Private
Automatic Branch Exchange) or EPABX (Electronic
Private Automatic Branch Exchange.) |
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| Several interacting single-line phones and/or multi-line phones
connected to a box that provides features of both key systems and PBX systems, called a hybrid system. AbleComm specializes in hybrid
systems.
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| Several interacting single-line phones and/or multi-line phones
with the features of a PBX system, but no box on the wall of your business, because the
switching and features are provided by equipment in the phone company's Central Office.
This is usually called Centrex service in
former AT&T phone companies, and has other names in other places.
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It is
sometimes desirable or necessary to have a self-contained phone system in a place of
business, that is also connected to a Centrex or Centrex-like system. I know of no
specific term for these combos, but you will sometimes hear about a key system or PBX
installed in front of Centrex, or behind
Centrex.
Michael N. Marcus |
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