Dial-Up Internet Access
Dial-up internet access involves using your telephone line and a modem to connect to the internet. The modem dials the telephone number of another computer's modem belonging to the ISP, which routes traffic back and forth between your computer and the internet.
As dial-up access uses the same connection as a telephone call, there are 2 main limitations:
- You cannot use your telephone at the same time as the internet (if your modem uses the same telephone line). This is because essentially, your computer is making a phone call, and consequently your phone will register as engaged.
- Speed: Because dial-up uses the same frequency range as a telephone call, not much data can be sent / received at one time (low bandwidth). This is because the telephone system was designed to use only the bandwidth required for a telephone call, which is quite low.
Dial-up ISPs can be split into three groups according to what they provide, and how they charge for it:
ISDN also falls into this category to a certain extent.
Free ISPs
A 'free' ISP is a company which will provide you with a dial-up connection, usually through a local- rate phone number (0845), without charging you any monthly costs or setup fees. Free ISPs became extremely popular because there was no financial or contractual commitment to the ISP. You log on to the internet, surf for as long as you like, and pay for a local phone call when your phone bill arrives. Many broadband and subscription users will still keep a free ISP number configured on their computer, should their main access to the internet fail temporarily.
How do Free ISPs recoup their costs? Many free ISPs will charge premium rates for telephone support (up to £1 per minute in some cases), and a lot will change your homepage to their member 'portal' page, which is usually packed with advertisements and pay-per-click links. There have been some reports of free ISPs aggressively enforcing this, by installing programs or scripts on your computer which will change your homepage back to their portal page if it detects you have changed it to something else. Some Free ISPs will provide you with webspace on their servers for you to mount your own pages, and will add their own banner ads or pop-up ads on the pages you upload.
Subscription ISPs
Essentially, a subscription ISP works in the same way as a free ISP, but they will charge a monthly fee in return for better service. This is usually defined as better uptime, less dropped connections, and in some cases, free or cheap telephone support. You still pay local rates for the time you are online.
Unmetered ISPs
An unmetered ISP will charge a monthly subscription for dial-up access, but will provide you with a free (0800) number to connect to the internet. In order to avoid abuse, they will normally place a time limit on the amount of time you can spend online in one session (roughly 2 hours) after which your connection will be dropped and you will have to reconnect. It is therefore recommended you use a download manager such as Star Downloader which can recover incomplete downloads due to a dropped connection.
ISDN
Integrated Services Digital Network (ISDN) is a type of dialup internet access method which requires you to have 2 digital telephone lines installed in your home or office. Each line is capable of transmitting data at 64kbps, and can be used together (to create one 128kbps line) or separately (e.g. between two computers). See the BT Highway homepage for more information.