3Com 3C10402B, Руководство администратора

Страница: 261 / 582

Dial Plan Concepts and Overview 261
3Com recommends that you reboot the system each time that you
change the dial plan.
When you reboot the system, you disrupt service to the telephones. Plan
to reboot at a time that does not inconvenience telephone users.
Pretranslation Pretranslation is the process of translating (or manipulating) dialed digits
before they are passed to the appropriate dial plan table for subsequent
routing. You can set the dial plan to perform pretranslation on incoming
or outgoing calls. For more information, see
“Dial Plan Pretranslators” on
page 270 .
Routing Routing specifies how a call reaches a destination. You define the routes
for the system to use in the Routes section of the dial plan configuration
file.
When you define call routing, you can also instruct the system to perform
pretranslations. Both destination routes and timed routes have digit
manipulation operations (
append, prepend, replace, stripLead, or
stripTrail) .
The system passes dialed digits first through the device’s Least Cost
Routing table (if there is one). If the system finds no entry, it then uses the
Normal dial plan table. If the system does find an entry in the Least Cost
Routing table, it attempts to use that entry and, even if the attempt is
unsuccessful, it does
not use the Normal table.
You can route incoming calls to the Auto Attendant port, and you can
instruct the Auto Attendant to route these calls to any internal or external
number.
CAUTION: If you configure the Auto Attendant so that it can access any
external number, you risk the possibility of toll fraud. To reduce the
possibility of toll fraud, include specific external numbers in the outgoing
dial plan table. This precaution prevents outside callers from dialing any
external number except the ones that you define.
There are two types of routes:
■
Destination routes — Specify the extension of a destination device.
They can also perform digit manipulation operations on the dialed
digits that resulted in the selection of this route before those digits are
dialed on the destination device.