Enterprise VPN-based VoIP Solution

1.1 Introduction
For enterprises with branches in different regions, using a VPN-based VOIP Solution can not only greatly save the company's spending on communication fees, but also the VPN-based network, secure and reliable. At the same time, it also lays a good foundation for enterprises to further develop integrated networks for data, voice, and video services, protecting their investment to the greatest extent possible.
1.2 Networking requirements
The VoIP Gateway12xx and 15xx voice gateways work together with the IP address phones of the VoIP ePhone 20x series to perfectly connect the VoIP communication network with the original PSTN communication network of the enterprise. Requirements
The enterprise headquarters has the VPN access function. Each branch of an enterprise uses a secure VPN to form a private IP communication network within the enterprise, with an independent IP address space.
An external phone can call any enterprise IP address phone through the PSTN network by dialing the switchboard of the enterprise headquarters/branch, and then dialing the scoring machine number.
No matter the internal phone number of the enterprise headquarters or the branch office, you can call each other by dialing the short number assigned by the enterprise.
The phone number can be moved by any employee. You can have the same number whether you are on a business trip at the headquarters, in a branch, or in a field without a branch.
Enterprise-level GK is easy to use, reducing the difficulty of enterprise maintenance.
1.3 networking Diagram

Enterprise VPN-based vojit application networking Diagram