Lucent Technologies Definity Enterprise Communication Server 8.2 User Manual

Issue 1

April 2000

Features and technical reference 

1385

IP trunk service 

Possible sites for originating a call to Terminating Site-1 are labeled O1 (for 
Originating Site-1), O2, and so on. A call can terminate on a telephone connected 
to the switch at T1, or it can be routed “off-premise” to terminating sites T2, T3, 
or T4. Since the IP calls received at Terminating Site-1 are dialed the same way as 
conventional calls, even if no off-premise dialing is configured, the telephone 
number received will differ depending on where the call originated:

■

Calls from Originating Site-O1 (which is within the same area code as T1) 
contain only exchange and extension portions. 

■

Calls from O2 (which is within the same country, but in a different area 
code than T1) contain a long distance access code and an area code, as well 
as an exchange and an extension.

■

Calls from O3 contain an international access code, a country code, an area 
code, an exchange and an extension.

In all three cases, the DEFINITY IP Trunk application at Terminating Site-1 
changes the digits in the telephone number received to match what the switch 
expects to receive for a call to one of its extensions.