connect.ie
How fast will my computer connect
Various factors can determine how fast a modem connects, including :
Modem Speed
A modem will never connect higher than what it is rated for, although
it can connect to a higher speed modem. That is, a 28.8k modem can
connect to a 56k modem but it will never connect at higher than 28.8k
speeds. Modems generally come in the following speeds, 2400, 9600,
14.4k, 28.8k, 33.6k and 56k.
The Telephone Companies Switch
Whenever you call someone your call goes through to the phone
companies exchange, where it is converted to a digital signal. It
then goes through to the exchange of who you are calling and is
translated back into an analog signal on the other end. The switching
in the phone companies office usually goes about 56k. This is why 56k
is the theoretical maximum limit a modem can go. In the past, modems
could only communicate at up to 33.6k. This is because if a modem
calls another modem that is on a normal telephone line, there is a
mathematical law which says that you can only get about half the
speed of your switch, which with all the maths ended up being 33.6k
in most cases. In order to get to the higher speeds one of the ends
needs to be digital. A normal 56k modem calling another normal 56k
modem cannot get above 33.6k speeds.
FCC Regulation
In order to get 56k speeds, modems need to produce higher voltages on
the phone line. The FCC has a regulation that limits the voltages
that can be placed on phone lines in order to prevent crosstalk
between lines.
For this reason, 56k modems can only effectively go up to 53k.
Phone Line Conditions (static)
If you can hear audible static on a phone line, then more than likely
the modem will not only connect very slowly, but they may not connect
at all, or disconnect very quickly. Even if you can't hear static on
a phone line, there may be faint static that is beyond the human
hearing spectrum that is causing the modems to not get their full
speeds.
Distance from the Phone Company's Exchange
This mostly affects 56k modems, but may also have some play with V.34
modems. If a user is further than 3 miles from their phone company's
exchange, they will not generally get above 33.6k speeds. The reason
distance makes a difference has to do with the voltage level that
modems need to produce, and the further you are from the phone
exchange, the more impedance the phone lines have. Also the more
further away, the more chance for noise to happen on the lines.
How the phone lines are wired to a location
In order to reduce costs many developers of new housing complexes are
putting in systems that will run more phone lines over less pairs of
wires. Sometimes this is called pair gain, although this may not be
the proper technical term. If one of these systems is in place, it
will stop a person from getting over 28.8k speeds. Also the phone
company may put filters, or other devices between the exchange and
the end user that will slow down the speed the modem may go.
Internal Wiring
How the phone lines are wired inside a house can make a large
difference on modem speed and reliability. If a person has 2 phone
lines, sometimes the noises from one line will bleed into the other.
This is called "crosstalk". It is very rare that this will cause
major problems but it will slow down a modem. Some people also get
remote phone line boxes that plug into a power outlet and allow them
to run phone lines into rooms they don't have a jack in. Although
these are advertised to be used with modems, in general they will
cause a huge performance decrease and will often cause the modems to
disconnect.
Brands and type of Modem
Different brands and types of modem vary widely in quality and have a
large effect on speed and reliability.
A user service from Connect.ie, free to copy, free to use, please notate source.