Internet access terminology can be very confusing, especially if you’re trying to choose a new ISP. Each technology has its differences and some may be better at certain tasks than others, consequently it is important for consumers to understand the advantages and disadvantages of each prior to choosing a provider. This page seeks to explain the methods using simple language and is best used in conjunction with our 'Jargon Buster' section.

Dialup is one of the oldest forms of Internet access technology, which uses a simple adaptor known as a modem (modulating demodulator) to plug directly into a standard old telephone line (POTS). The modem converts a computers digital data signal into a transmission that can be sent over the voice line for communication with a remote computer (ISP). Dialup connections incur the standard voice call charges of your existing telephone operator, which varies depending on the number dialled (local call rate or unmetered/free calls).

This form of Internet access is extremely slow (speed and latency) and highly susceptible to line interference, running at a theoretical maximum of up to just 56Kilobits per second (Kbps) downstream and 48Kbps upstream using the latest (last) v.92 standard (details). Thankfully its ability to plug in to almost any phone line makes it very flexible and useful as a temporary backup solution for when your broadband service fails, though you cannot make separate voice calls while using it.

Dialup Standards and Download Speeds:
Modem 0.3Kbps (Bell 103 or V.21)
Modem 1.2Kbps (Bell 212A or V.22)
Modem 2.4Kbps (V.22/26 bis)
Modem 4.8Kbps (V.27ter)
Modem 9.6Kbps (V.32)
Modem 14.4Kbps (V.32bis)
Modem 28.8Kbps (V.34)
Modem 33.6Kbps (V.34)
Modem 56Kbps (V.90)
Modem 56Kbps (V.92)

Dialup's top speed of 56Kbps (0.05Mbps) could take anything up to one minute to load most modern web pages. Some UK ISPs enhance this by using server-side compression, which makes the connection appear to be several times faster, although it has no impact on pre-compressed images and files. Users can also make use of web browser cache or separate compression applications (e.g. OnSpeed) to improve performance.

These days Dialup has been largely replaced by DSL (e.g. ADSL), which is the world's most popular form of broadband connectivity and can also make use of existing telephone lines, albeit at considerably faster speeds of up to 8Mbps (ADSL), 24Mbps (ADSL2+) and 60Mbps (VDSL2). See the 'Broadband DSL' technology page for more. Related ISPreview Sections:
    Dialup ISP Listings - Unmetered (Free Calls)
    Dialup ISP Listings - Local Call Rate
    Dialup (Unmetered) Reader ISP Reviews
    Dialup ISP Discussion Forum