Connection to any ISP requires these two things as mandatory which are hardware for connectivity such as a modem and a working cable line and software such as protocols to govern the data flow and connections. These governing bodies typically already lie in the operating system of your system and any application written to take advantage of TCP/IP services can do so.
ISP’s services
Once you make a contract with ISP, to grant you access to the Internet and establish the connection, they will either send you technician or email you the necessary instructions or hardware/software you need.
Generally most of the ISPs will provide your computer with the right TCP/IP information via DHCP (Dynamic Host Control Protocol) server. The router you connect to which connects to your ISPs is known as the default gateway. Once the necessary configuration is done, you are good to go and connect to the Internet. All of these connectivity is managed by various other software and protocols.
Connecting to the Internet
Computers typically connect to the ISP via one of the eight technologies out there that fit into four categories. They are dial-up, both analogue and ISDN; dedicated ones such as, DSL, cable and fibre; wireless ones like Wi-Fi, cellular; and satellite.
Among these, Analogue dial-up is the slowest and requires a telephone line and a sort of special networking device called modem. This was the medium widely used back in 90s and early 2000s but not anymore. ISDN, utilize a digital dial-up connection with much greater speed. Dedicated connections like DSL, cable and fiber typically uses a box that connects to one of the regular Ethernet NIC. Wireless connections are mixed up and depends on the device and service you have and use.
Dial-Up
Dial-up connection in order to work, requires two pieces to work properly. A hardware, which dials the ISP like a modem or ISDN terminal adapter and a piece of software to monitor and govern the connection like one of the Microsoft’s dial-up Networking (DUN).
Modems
At the very early days of innovations for Internet, people came up with the idea to use the telephone line to use establish connection to the Internet. While this worked, this was one of the worst way to connect to the Internet directly. Telephone line uses a pure and raw signal while the computers use digital signals. To create and establish the connection to the Internet, required some sort of device that could turn that raw signal into a digital signal. The idea is to turn the digital data into a raw signal and send it over the telephone line and before receiving the signal on the other end, converted back to digital signal. To address this issue Modem was made and played huge role back in the days.
Modem connections
Internal modem connects to the computers differently than external ones. Almost every internal modems connects via the PCI or PCIe expansion slot on your motherboard. There were contemporary external modems which could connect to the computer via an USB port. This that being an USB modem, it was simply a plug-n-play mechanism without the hassle of external electrical source since they got their power over USB.
Dial-up Networking
In order to dial up network to work, you need to configure this on the software level provided by your operating system. You ISP would provide you with a dial up code or numbers along with your user name and initial password. In addition, your ISP would provide your with any further instructions on configuring the setup if needed.
Configuring dial-up on Windows 7, open the Network and sharing centre applet and hit the Set up a new connection or network. You will be prompted with a box full of input filed like forms. There you need to type in your user name, password and dial up number.
PPP
Every dial-up links have their own hardware protocol called point-to-point protocol (PPP). PPP is a streaming protocol which was developed for dial-up Internet access. You can always configure a new dial-up connection in the networking and sharing centre in the recent version of windows as well.
Note that most of the error occur in a dial-up connection is due to the user error. Probably a type or something like that. In any such error, you need to investigate first before calling in the techs. Check in the modem’s properties and see if the volume is turned up. See if you can hear the connection.
Do you hear the dialling tone? If you do not. check for simple thing like if the modem is plugged-in into the power or the modem’s line is plugged into a good phone jack. If you hear someone answering on the other end, that is a wrong number! Recheck all the input field, if all is well from your end then it is time to call in the techs.