Apple Remote Access MultiPort Server - Manual (Page 15)

Requiring a callback number for users further ensures security because users
can only connect to the server using a telephone number that they have
provided to you. When a user successfully logs in, he or she is immediately
disconnected from the server. The server then attempts to make a connection at
the callback number listed for that user. If the telephone number is valid, a
connection is made.
To maintain a high level of security for your network, you should require all
users to supply callback numbers. For users who require “roving access”—
that is, users who need to access the server remotely but aren’t always in the
same location—you should implement external security software. For more
information about this option, refer to “External Security,” later in this chapter.
IMPORTANT Many cellular modems use the MNP 10 error-correction protocol
to improve communications reliability. Because cellular phones vary in the
way they receive incoming calls, cellular phones equipped with MNP 10
modems generally cannot receive callbacks. Use a security method other than
callback for cellular clients.
Zone access
Zones are logical subdivisions of a network in which services such as file
servers, printers, and other individual computers reside. Zones appear in the
Chooser window. You can use zones to organize services into logical groups.
Groupings can be by type of resource, along organizational boundaries, or in
any manner the network administrator decides. The Apple Remote Access
MultiPort Server administrator can assign each user access to specified zones
on the network.
Note: Although zone access cannot be considered “true” security when compared
with password and external security, it does provide a way for you to control
access to the network.
Including a large number of zones in users’ zone access privileges can slow
down server performance. If you want to exclude a user from a large number
of zones, choose “All Zones Except Listed,” or “Only Zones Listed” instead of
naming the zones specifically. See “Creating a New User,” later in this chapter,
for more information. For best performance, always try to minimize the
number of zones per zone list.
About server security 15