Installation guide

122 Planning and Installation Guide ShoreTel 14.2
Network Call Routing Overview
7
Overview
When a phone number is dialed in a ShoreTel system, the system performs three distinct operations
on telephone numbers:
Digit collection — Voice switches collect the digits in a telephone number.
Network call routing — After collecting the digits, the switch checks the number against a user’s call
permissions, adds trunks to the route list, and makes a final route decision for the call.
Digit manipulation — The switches manipulate the dialed numbers before outpulsing them to the
service provider.
In this chapter you will learn how to plan your network call routing.
Define Network Call Routing
Once an external telephone number has been collected, the switching software checks the number
against the user’s call permissions, finds the list of available trunks, and then makes a routing decision
based on several criteria.
Call Permissions
Each dialed number is compared against the user’s call permissions. If the call is denied, the calling
party will be routed to a fast busy intercept tone. If the call is allowed, the routing continues.
Complete the following steps to define call permissions:
1. Open the Call Permissions edit page, which is shown in Figure 21.
Figure 21: Call Permissions Edit Page