An external modem installation has its own box with a power cord, and is connected to the PC via COM port (the serial port or the USB port). An internal modem insatllation is an expansion board fitted into a slot on the motherboard. It may have its own speaker so that you can hear when it is dialling up.
Picture below shows the modem connections needed to position a modem between the PC and the telephone line. The RJ-11 connector is used to link the normal phone line to the modem, and then, for an external modem, from the modem to the PC. Make sure you do not confuse the line and phone jacks.
As with any modem, you should read the instructions. For an external modem first steps!
For internal modem follow the same process as installing any expansion board
A modem needs both to send and receive data, preferably at the same time. Modem Installation, Communication that can be done in both directions, but not at the same time, is called half-duplex transmission.
If the communications can be both ways and simultaneous, this is called full-duplex transmission. When the modem first dials up, the sounds you can hear indicate that handshaking is taking place:
When a modem answers an incoming call, it sends a guard tone to indicate to the caller that connection has been made with a modem, and not with a human. The caller responds either by putting the phone down, having dialled incorrectly! or if it is another modem, by sending a carrier signal.
Having agreed that both ends of the line are modems, the next stage involves much buzzing to establish the quality of the line and an attempt to compensate for any noise. The speed at which transfer will happen is then agreed between the two modems.
So, during the initial handshaking stage, the two computers exchange 'rules' or 'protocols' that will determine how they communicate: at what speed the transfer of data will take place, how data might be comppressed and what error might be incorporated.
The speed at which the communication happens depends partly on the speed of the modem (given in bit perseconds) and on the amount of noise on the line, and also on what route the data is to take.
If the route includes a slower patch, then the best speed will the speed across that slower link. There are othere ways of communicating between computers. Cable,DLS and satellite all offer broadband internet access, without the need for modem. All involve installation, according to the manufacturer's instructions, and under the control of software supplied, usually on CD-ROM.