3Com NBX 100 Installation Manual page 77

Managing Extensions and Extension Lists 77
appears at the top of the list, because 1 is the highest priority (99 is the
maximum); extensions with lower priorities appear in priority order
farther down the list.
You can assign the same priority number to multiple extensions. The NBX
100 processes extensions with the same priority in the same order they
appear in the list.
The NBX 100 establishes connections between extension numbers. The
concept of an extension applies to more than just telephones. Extensions
are assigned to Call Park zones, Line Card ports, voice mail ports, and
virtual devices such as the pcXset PC Telephone Client and the
ConneXtions H.323 Gateway.
Example: When you park a call using the Call Park feature, the Call Park
number you assign to the call is a special, reserved extension number. Any
user who wants to pick up the parked call must dial that extension.
The system restricts access to any specific analog and digital line card
port. To directly dial the extension number associated with one of these
devices, you must have diagnostic privileges. In addition, you can not dial
a prefix to obtain a Digital Line Card port.
Each Line Card port must have its own extension. Telephones cannot
have an extension unless you associate a user with that extension. The
auto discovery process initially assigns a default name (new user) to each
new telephone, and assigns an available extension number. To assign a
telephone extension to a user, you replace the default name with that
person's name.
You can define a user in the NBX 100 database without assigning a
telephone extension to that user. Each defined user has voice mail;
therefore, when you define a user with no device, but with a telephone
extension, you create a Phantom Mailbox. The NBX 100 associates an
extension with this mailbox so the user can use voice mail. To access voice
mail from any telephone, the user calls either extension 500, the default
auto attendant extension, or 501, the default voice mail auto attendant
extension.
Business Telephones and Line Card ports reserve most of the extensions
within the NBX 100; however, there are other extensions within the
system. Table 10 shows, for 3-digit and 4-digit systems, the default
extension ranges for all devices in the NBX 100 database.