5.3 ISDN Uses
5.3.2 ISDN remote nodes

With the remote nodes method, as shown in Figure , the users connect to the local LAN at the central site through the Public Switched Telephone Network (PSTN) for the duration of the call. Aside from having a lower-speed connection, the user sees the same environment the local user sees. The connection to the LAN is typically through an access server. This device usually combines the functions of a modem and those of a router. When the remote user is logged in, he or she can access servers at the local LAN as if they were local.

This method offers many advantages. It is the most secure and flexible, and it is the most scalable. Only one PC is required for the remote user, and many client software solutions are available. The only additional hardware required at the remote location is a modem. The main disadvantage of this method is the additional administrative overhead required to support the remote user. Because of its many advantages, this solution is used in the remainder of the design examples in this chapter.

The full-time telecommuter/teleworker is one who normally works out of the home. This user is usually a power user who needs access to the enterprise networks for large amounts of time. This connection should be reliable and available at all times. Such a requirement would generally point to ISDN as the connection method, as shown in Figure .  With this solution, the ISDN connection can be used to service any phone needs, as well as to connect the workstation.

Threaded Case Study
  Washington Project: ISDN Requirement

A small remote site will require connectivity to the Washington School District WAN from time to time. You should use ISDN technology to make the small site a remote node on the WAN.