ISDN is a telephone company technology that provides digital service typically in increments of 64Kbps channels. ISDN has been around for many years, but it's popularity is now only beginning to increase due to the limitations of analog modems and the rise of Internet usage. ISDN requires the phone company to install services within their phone switches to support this digitally switched connection service. Roll out of this service initially got off to a slow start and was stalled by high costs, lack of standards and low acceptance rate by consumers. As prices of DSL decrease, the popularity for ISDN will also decrease.
Cable modems are devices that attach to the cable TV network connection in a home.
This broadband technology is being driven by the cable companies to provide services beyond traditional broadcast cable TV such as Internet access. Potential bandwidth estimates range upwards of 30Mbps from the service provider to subscriber. Cable modems are primarily used for consumer service. Cable networks are inherently different in design than telephone networks. Cable networks are broadcast oriented, meaning with each subscriber in an area receiving the same signals as all others in that area.