Internet has become part and parcel of our lives. Not only for individuals but even for a country's economic growth, scientific growth, organizations' success, Internet is very essential. The companies that offer these internet connections are called ISPs (Internet Service Providers). These ISPs offer many different internet connection plans. How to select the best connection plan for home use or for offices? The following tips will give you an overview of different types of internet connections, their advantages and disadvantages.

PSTN Dialup

Public Switched Telephone Network (PSTN) dialup uses your phone connection to connect your computer to the internet. You need a modem, phone line and a computer for a PSTN dial up connection.

Advantages of PSTN dial up

1. This is the basic internet connection and all the ISPs provide this type of dial up.
2. To install PSTN dialup and to use it is very cheap and affordable.

Disadvantages of PSTN dial up

1. The speed of a typical PSTN modem is 56KBPS. Therefore the speed of the internet connection will be slower than this.
2. During the time you are connected to the internet, you have to pay the telephone charges.
3. While you are connected to the internet you cannot use your telephone to call anyone because you are using that phone line for connecting to the internet. You also will not receive any calls from outside during this time.

ISDN dialup

Integrated Services Digital Network (ISDN) dialup uses a higher end digital telephone line to dial up. To use this type of connection you need ISDN telephone line, computer and a 'Terminal Adapter'.

Advantages of an ISDN dialup

1. While you are connected to internet using ISDN dialup connection you can use your ISDN phone to make phone calls simultaneously.
2. When you are making phone calls while connected to the internet then the speed of internet will be 64KBPS.
3. If you are using the ISDN phone line just for internet then the speed of internet will be 128KBPS.

Disadvantages of ISDN dialup

1. Not every place has ISDN connection.
2. Even if your place has this facility, it is expensive to get an ISDN dialup connection from your ISP.
3. Not all the ISPs provide ISDN dialup plan.

Leased Line Internet Plan

In both ISDN dialup and PSTN dialup you need to dial up from your computer before getting connected to the internet. And you close this connection when you no longer need internet connection. If you need a continuous connection 24 hours of the day and 7 days a week then you need a 'Leased Line' also known as 'dedicated line'. This type of permanent connection is called 'Always On'.

Advantages of Leased Line

1. You get 'Always on' connection 24 hours every day.
2. The speed of the internet ranges from 2.4 KBPS to 2G based on your subscription.

Disadvantages of Leased Line

1. The disadvantages of a leased line is that it is very expensive.
2. Since your computer is always connected to the internet your computer is exposed to many vulnerabilities such as viruses and spywares. So you may need to secure your computer using firewall and Antivirus software

DSL

1. Digital Subscriber Line (DSL) also uses a normal PSTN phone line. But using DSL you can use both internet and phone simultaneously. Therefore many prefer DSL to PSTN dial up.

Advantages of DSL

1. The speed of DSL connection is fast. 64 KBPS, 512 KBPS, 1.5MBPS and higher speed can be achieved in DSL connections.
2. DSL also provides 'Always On' connection 24 hours a day always.
3. You can also use your phone while using internet

Disadvantages of DSL

1. More expensive
2. You need an ADSL modem to connect but the distance between this modem and your computer cannot be more than 18,000 feet.