USRobotics NETServer/8 - Manual (Page 14)

1-6 Overview
IP Modem Sharing
Hosts on a local IP network can use a chassis modem to dial out.
Moreover, the NETServer can create pools of modems that can
be used by local hosts on a first come, first serve basis.
To do this, the NETServer allows the host to establish a virtual
terminal session with the modem. The host can then interact
with the modem’s command line and from there, dial out.
On a UNIX host, you can install a pseudo TTY driver that allows
the host to interact with this virtual terminal connection as if it
was actually a serial port. This makes the modem appear to be
directly connected to the host.
Network Dial In Access
Remote IP and IPX users can dial in and attach to the local
network as if they were local nodes. IP and/or IPX packets are
transmitted over a dial in connection encapsulated in a serial
line networking protocol (PPP or SLIP). When received by the
NETServer, the IP and IPX packets are forwarded from the
remote user to the LAN and vice versa.