Free
Dialup UK Article - Main Types Of Modems
The modems come in several different types. Several vendors
make different types of modems and the market is crammed up
by vast array of types of modems available. However, modems
can be generally distinguished in the three most common traits.
These traits are hardware modems, software modems and Controller
less modems.
Hardware based modems are highly compatible and independent.
They can work with every operating system from Apple Macintosh,
DOS, All versions of Windows and UNIX. All hardware modems
are assembled using essential parts to make it capable of
handling entire communication process by itself. A hardware
based modem does not rely on the computer's CPU to do the
processing of the information to send over the internet. It
may requires nothing more from the computer's CPU after it
is connected. The only information would be required from
the computer's CPU is to the access number it is supposed
to call, when to make the call and when to terminate connection.
A Hardware modem is much better at sending and receiving packet
information and correcting errors due to its independent nature.
It also handles poor quality phone lines much better than
software based modems. All external modems are hardware modems.
They connect to computer’s serial port through a cable.
In software modems, some part of the modem functions is handled
by the software emulations. Notably, both the Data Pump and
the Data Controller are emulated in the software. The hardware
part of the modem contains only the basic circuitry to connect
to the telephone network. The computer CPU manages the main
function of the software modem. Since a software modem is
designed to depend on software, it follows the programmed
instructions into the software to tell the hardware part of
the modem as how to react under various circumstances. The
limitation of the software modem appears when an exception
condition arises which does not match conditions it is programmed
to handle. In these circumstances the modems shows symptoms
like frequent disconnects, slow connections and overall poor
performance.
The remedy to this situation is often relies in driver updates.
Hence, if you have these types of problems you may load driver
update that can supply the modem with more programmed variables
then the current version. The software modems are known to
cause problems. The attraction lies in inexpensiveness, as
they are exceptionally low-priced to manufacture and to sell.
The third main type of modem is a controller less modem.
These modems are partly software and partly hardware modems.
The hardware part would still contain a hardware data pump
but as them name suggests, its Data Controller functions not.
They are emulated in software. The advantage gained by excluding
one of the main chips from the modem is to cut the cost for
producing those modems. In addition, the modem can easily
be upgraded by simply installing new software provided by
the vendor. The disadvantage is that it is not very compatible
and has difficulties with lesser quality phone lines. This
may result in slowdowns, disconnections or long time taken
in establishing the connection.
|