12th May 2008

Internet Connections explained, A guide to dial-up, ADSL and Cable connections

Welcome to our guide to Internet connections.

In this section we will explain the pros and cons of the different internet connections currently available for home users.

There are various connection types on offer from the different internet service providers, your choice will depend on how often and how you intend to use the internet.

The connection types in this section include:

Dial-up Connections
ADSL Connections
Cable Connections

Dial-up connections
Dial-up connections are the most common type of internet connection available from ISPs, they are also the slowest and (usually) the most inexpensive.

A dial-up connection allows you to connect to the internet via a local server using a standard 56k modem, your PC literally dials (hence the name) a phone number (provided by your ISP) and connects to the server and therefore the internet.

note: In the US the FCC passed a regulation limiting V90 dial-up connections to 53Kbps.

Once connected you can utilise all aspects of the internet, the drawback with a dial-up connection is the speed, a standard 56k modem can theoretically transfer 56 Kilobits of data a second, this means that you can (again theoretically) transfer up to 7 Kilobytes a second (although to get a full 7k is near impossible due to the compression overhead).

When you consider the average web page including images is around 50 Kilobytes, this means it would take around 7 seconds for the web page to completely load in your browser.

On top of this most (though not all) internet service providers charge by the minute for your connection, so the longer it takes to load the pages you visit, the more you pay for your connection. The cost is usually the same as you would pay for a local phone call so as long as they are used sensibly they can be a very cost effective internet connection.

Dial-up connection Pros

Dial-up connections can be very economic and are widely available, the cost is usually the same as a local phone call or priced as a monthly plan. As these connections use a standard modem the hardware costs are minimal.

Dial-up connection Cons

Dial-up connections are very slow compared to other connection types. When connected to the internet the same phone line cannot be used for phone calls so if anyone phones you when you are connected they will get the busy signal.

Dial-up connections transfer data over an analogue line so before the data is sent it has to be converted from digital to analogue, likewise when data is received it has to be converted from analogue to digital (this is what the modem does), this adds a performance overhead which affects the speed of the connection.

ADSL connections
ADSL (Asymmetric Digital Subscribers Line) connections are becoming more and more widely available and can provide an excellent internet connection.

The connections work by splitting your phone line into two separate channels, one for data (internet) and one for voice (phone calls) which means you can talk on the phone and be connected to the internet at the same time.

You will often see ADSL connection services advertised as having different speed specifications, below are some common configurations:

256Kbps/128Kbps
512Kbps/128Kbps
1Mbps/256Kbps

Notice there are two values to each configuration, the first figure states the download speed and the second figure is the maximum upload speed.

As an example let's take the second configuration 512Kbps/128Kbps, this means that you can potentially download data at a speed of 512Kbps and upload data at 128Kbps.

The most important figure is the download speed, this depicts how long it will take to view a web page, download a music file or an email attachment.

As an example of how the different download speeds can affect your connection, below are some figures to give you an idea of the differences:

Average Web Page (50 Kilobytes including images)

256kbps download speed - roughly 1.56 seconds to view page
512kbps download speed - roughly 0.78 seconds to view page

Average MP3 file (music file) (4 Megabytes)

256kbps download speed - roughly 2 minutes and 8 seconds to download.
512kbps download speed - roughly 1 minute and 4 seconds to download.

The figures above are theoretical as there are many other factors which determine the real download speed (such as the speed of the server/host you are downloading from).

As you can see ADSL offers incredible performance compared to standard dial-up connections and is becoming the first choice for most internet subscribers.

Most ISPs that offer ADSL packages charge a flat monthly fee which normally includes a certain amount of bandwidth each month

ADSL connection Pros

Apart from the obvious speed advantages that ADSL connections offer, ADSL technology eliminates the need for a second phone line by allowing voice and data transfer at the same time (you can use the phone as normal while connected to the internet).

Because ADSL transfers data digitally it eliminates the usual performance overhead associated with standard dial-up connections, in other words ADSL doesn't need to convert the data from digital to analogue and back again.

ADSL connections are Always on, which makes the usual long wait to connect a thing of the past.

ADSL connection Cons

ADSL connections are not available to everyone, you should always ensure that you have ADSL coverage in your area (an ISP will check for you). The hardware costs can be quite significant as you will need a special ADSL modem and ADSL filters to use the service, most ISPs allow you to hire these items which can reduce the initial cost.

Because ADSL connections are Always on you will need a firewall to protect your PC, for a free firewall see our Freeware and Shareware section.

Cable connections
Cable connections are considered one of the best types of internet connection available to the home user, they offer very fast and reliable connections with a fixed monthly fee.

Cable companies usually offer different packages to suit different internet subscribers, your choice of package, as with all internet connections will depend on how you intend to use the internet.

The different packages will offer different speed specifications and bandwidth limits.

Because a cable connection uses a totally separate medium to transfer data it doesn't affect your ability to make/receive phone calls.

Cable connection Pros

Speed is a major reason for having a cable connection, with very high speed packages available it is an excellent choice for those who don't like to wait around tapping their fingers when downloading big files such as music or large attachments.

Like ADSL connections, cable connections transfer data digitally, eliminating any digital/analogue conversion overhead.

Cable connections are Always on, eliminating long waits to make a connection.

Cable connection Cons

Cable connections are not available in every area, you will need to contact the cable company of your choice to ensure that you have coverage.

Because cable connections are Always on you will need a firewall to protect your PC, you can find a free firewall in our Freeware and Shareware section.