An acronym for Integrated Services Digital Network, ISDN lines are connections that use ordinary phone lines to transmit digital instead of analog signals, allowing data to be transmitted at a much faster rate than with a traditional dial-up modem.
ISDN was the first high-speed Internet service, which sparked the mass migration from dial-up Internet connections to broadband connections such as cable and DSL, staring in the latter 1990s. ISDN made it possible to connect to the Internet without tying up your phone line and introduced speeds that were capable of downloading large files, streaming media, and video chatting, which was nearly impossible to accomplish over a dial-up connection.
There are two types of ISDN Internet services available to customers:
- Basic Rate Interface – This type of ISDN utilizes two data channels, each capable of operating at 64 kilobits per second (kbps). While this is significantly slower than modern DSL or cable Internet speeds, multiple ISDN-BRI lines could be combined together to provide speeds up to 256 kbps.
- Primary Rate Interface – This type of ISDN provides significantly higher speeds by combining 23 channels together for speeds up to 1.5 mbps, which is faster than some DSL plans and on par with many starter cable Internet plans.
While ISDN still exists, you won’t find it offered by many ISPs. ISDN is considerably more expensive than DSL or cable Internet, and recent advancement in other technologies have made other broadband services significantly faster than ISDN.
Today ISDN is largely reserved for business clients. Because ISDN is cable of sending both voice and data signals over the same lines, it is still a very efficient and reliable means of managing a company’s phone, fax, and video conferencing systems.