ZyXEL Communications P-2602HWLNI User Manual

Page of 496
 Chapter 12 VoIP Trunking
P-2602HWLNI User’s Guide
221
Figure 129   VoIP to PSTN Example - Incoming Authentication 
12.8.4  Call Progression  
The advantage of this kind of VoIP trunking is that once all the configuration is completed, the 
caller just has to dial a speed dial entry from a phone connected to their ZyXEL Device and the 
peer devices take care of the rest. This is what happens when headquarters wants to call their 
Sales1 employee, which is the first entry in the speed dial screen.
12.9  VoIP Trunking Example: PSTN to PSTN via VoIP
This example shows how to configure a PSTN to PSTN call with a VoIP link. It also shows 
how call rules can be used to automate VoIP trunking.
Table 85   VoIP Trunking Call Progression
HEADQUARTERS 
BRANCH OFFICE 
SALES1
A person at A dials #01 from the phone 
connected to the ZyXEL Device.
The ZyXEL Device at A inspects the number and connects to the remote peer device at 
B.
The remote peer device inspects the number and requests authentication in order to 
forward the call.
The ZyXEL Device at A sends outgoing authentication to the remote peer device.
The remote peer device confirms that the username and password match an account in 
its incoming authentication list.
The remote peer device forwards the call to Sales1.
Sales1 picks up and the call commences.