Again, ISDN modems are close to obsolete, and no longer a common option for receiving fast Internet service. Unlike ISDN technology, to get a DSL connection you don't need to install a special phone line. You do, however need a special modem. DSL modems may connect at a rate up to 1.5MB per second, which is more than 25 times faster than a 56K modem, and 10 times quicker than an ISDN line. Some new high-end model computers come already equipped with a DSL modem.
Speed comes at a cost to users.
This option is available for only some people in the United States. The connection and download speeds of a cable connection are similar to that of a DSL connection, which is about 800Kbps to 1.5Mbps. The truth is, the speed at which you connect to the Internet or at which your modem operates, is dependent on a number of different factors. The first, of course, is the speed of your modem. A 56K modem connects to a server at approximately 33,600 bits per second, and downloads information at about 54 or 55K per second.