Dial-up services, most commonly used by home users, require an account with an ISP, a modem and an analog phone line. At a modem's sluggish pace, it can take several minutes to download a home page, a business presentation or a lengthy research document. And frustrations will only increase as new multimedia applications become more commonplace. Dedicated services, on the other hand, are priced according to bandwidth, not usage. They use digital leased lines from the phone company and are established at fixed locations at speeds ranging from 56 Kbps to a full T1.
Dedicated services provide reliability and performance, but at a higher cost and with no mobility.
Local phone companies can support ISDN BRI over the same twisted pair wire that carries regular phone traffic. Some ISDN Basics Integrated Services Digital Network, or ISDN, is an all-digital telecommunications technology that can simultaneously transmit voice conversations and data calls over the same pair of copper telephone wires. ISDN is part of an evolutionary process that started back in the 1950s to upgrade the telephone network from analog to digital technology. The ultimate goal of ISDN is to allow users to access voice, data, fax, video and graphics over the same phone line and enjoy the error-free performance that digital technology provides. Ultimately, this means that any communications equipment could be plugged into any phone jack anywhere in the world.