3Com NBX 100 Administrator's Manual - page 31
Dial Plan Concepts and Overview
31
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 processes inbound calls using the Incoming table. 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 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 124
.
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 124
.
If you have entries in both the Least Cost table and the Internal table for
the same purpose, the behavior of the dial plan can be confusing. 3Com
recommends that you accomplish least cost routing using Internal Table
entries. For more information, see
TimedRoute Create
,
TimedRouteEntry
Create
, and
TimedRouteOperation Create
later in this chapter.