Internet Connection

There are two main ways of connecting to the internet; dial-up and broadband. The differences are significant in terms of performance and each has its own unique security issues.

Dial-up

This is how the majority of people currently connect to the internet. A device normally inside the computer called a modem is able to connect to another modem at your Internet Service Provider (ISP) via a telephone line to add your computer to those on the internet. The speed is limited by the performance of the modems themselves and the available bandwidth on a single telephone line. Most modems today are quoted at 56kbps (kilo-bits per second) but in fact a typical connection speed achieved is more like 32kbps, due simply to the need to correct for errors that occur on the telephone link. If you want to learn more about modems you can find information at http://www.howstuffworks.com/modem.htm.

So what are the security issues specific to dial-up? The main one is that some unpleasant folk create software which will use your computer to dial-up numbers you don't want it to. This might be porn sites or other numbers which have high tariffs attached. This software can operate without you realising, so while you're working on one thing this software is doing another, such as racking up your phone bill or connecting to the internet to make your computer's resources available to others.

The main way to tackle this risk is to use the anti-spyware and anti-virus software we discuss in other pages, but there is also the highly effective method of unplugging the computer from the phone socket when you're not using it yourself. I accept for most people this is not a very practical suggestion as the cables and sockets are not conveniently located, but if you suspect a problem this is a highly effective measure.

Broadband

An excellent means of connection to the internet! More accurately this is a means of connection which provides a faster connection, anything upwards of 128kbps (i.e. at least twice as fast as a dial-up connection and frequently many times faster). Connection methods can be an ADSL modem, a cable modem or even a wireless connection. The advantages are that of increased bandwidth and instant or near instant access to the internet (typically described as "always-on" access). The main disadvantage from the security viewpoint is that an always-on connection is just that – always on. When you first connect to the internet your ISP will assign something called an "IP Address" to your computer. This address will typically be maintained for the whole period the connection is active – i.e. switched on. That means that the internet address you connect with remains constant for long periods and so poses a more stable target for others to attack. While this reinforces the need for a decent firewall, the simple step of switching off your connection when you don't want to use it (perhaps overnight) is a good secure practice. That way when you re-establish you connection the next time you turn on your computer a fresh IP address will be assigned by your ISP.