3Com 3C10402B, Administrator'S Manual

Page: 259 / 582

Dial Plan Concepts and Overview 259
Call Process Flow The dial plan configuration file is a key component of inbound and
outbound call processing. The dial plan tables in the configuration file
process
incoming calls in this order:
1 Incoming Dial Plan Table
2 Pretranslator Table
The dial plan tables process outgoing calls in this order:
1 Internal Dial Plan Table
2 Least Cost Routing Table
After pretranslation (if performed), the final translation process routes the
call to the destination.
Inbound and
Outbound Call
Processing
The system routes all inbound and outbound calls through the dial plan.
Inbound Call Processing
The system uses the Incoming table to process inbound calls. The system
can also use pretranslators to perform digit manipulations on incoming
calls before it uses the Incoming table.
Each pretranslator operation performs a digit manipulation operation on
the dialed digits. For incoming calls, if the DID/DDI (Direct Inward
Dial/Direct Dial Inward) range matches the internal extensions, the dial
plan requires no pretranslator. However, you can use pretranslators to
map nonmatching dialed numbers on an incoming DID/DDI channel to
desired internal extensions. See the example in Customer Requirement 1
in
“Sample Solutions Using Dial Plan Configuration File Commands” on
page 320 .
Outbound Call Processing
The system processes outbound calls using the Internal dial plan table or
the Least Cost Routing table. You can add entries to the Internal dial plan
table to match the system to your service. See Customer Requirement 2
in
“Sample Solutions Using Dial Plan Configuration File Commands” on
page 320 .
If you have entries in both the Least Cost and Internal tables for the same
purpose, the behavior of the dial plan can be confusing. 3Com
recommends that you accomplish least cost routing using Internal Table