Chapter 13 VoIP Trunking

13.8 VoIP Trunking Example: VoIP to PSTN

This example shows how to configure VoIP to PSTN trunking to save on long distance calls.

13.8.1 Background Information

A company has its headquarters in city A and a branch office in city B. The headquarters often needs to call salespeople employed at the branch office. The sales employees often work away from the office and have PSTN phones (mobile or land based). The two offices have VoIP trunking devices and want to use VoIP trunking to save on calls from the headquarters to their sales team. The head office has a public IP address a.b.c.d and the branch office has a public IP address w.x.y.z.

Figure 94 VoIP to PSTN Example

The proposed solution is to establish a peer-to-peer call between the two ZyXEL Devices and have the branch office ZyXEL Device forward calls to the sales team members via PSTN.

13.8.2 Configuration Details: Outgoing

The ZyXEL Device (at headquarters) from which the call originates needs to have the following configuration settings:

1Speed dial entries need to be set up for the numbers headquarters wants to call. The destination field of these entries is the IP address of the branch office ZyXEL Device. This must be a non-proxy IP address. The numbers are the phone numbers of the sales team members. This can be configured in the VoIP > Phone Book > Speed Dial screen.

 

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P-2302HWUDL-P1 Series User’s Guide