Not everyone has access to digital services yet. Several telephone service providers, particularly smaller, independent companies, have no immediate plans to implement digital-based services. Even in the larger RBOCs (regional Bell operating companies), digital deployment is spotty. Many users are located too far from the central office to be eligible for digital service.
While users have alternatives, however, they wait for the eventual deployment of digital services in their area. A variety of protocols have been designed to operate over analog modems. Protocols such as SLIP (Serial Line Internet Protocol) or PPP (Point-to-Point Protocol) are intended for remote TCP/IP network access.
Terminal servers, bridges, and routers are being equipped with PPP or SLIP capabilities that support modem access. Unfortunately, thes
e protocols add some overhead, so faster modems--nothing slower than 9600 bps--should be used for the connection.
Some vendors are building remote-network access protocols into their products. Apple's AppleTalk Remote Access allows a remote Mac to dial into an AppleTalk network. Network modems, such as the Shiva NetModem, allow modem-based remote access to AppleTalk and Novell networks.
Although analog connections are slower and less reliable than digital connections, they can be a perfectly viable alternative if digital services are unavailable or too expensive.
The Analog Alternative
