OpenVPN with Asterisk and FreePBX

SysAdminMan offers OpenVPN server setup on all hosted systems. This means you can rent a FreePBX server with OpenVPN server already installed and configured. You can connect any OpenVPN client to this but one of the easiest ways to get this working is to install the SysAdminMan customer firmware for the TP-Link 1043 broadband router.

This custom firmware is already configured as an OpenVPN client – you just need to enter your FreePBX server IP address along with the security credentials.

Why run OpenVPN?

Running a VPN to your FreePBX server in the cloud provides 4 benefits –

1. All traffic (telephone calls) between the phone and the FreePBX server are encrypted to prevent eavesdropping
2. Removes any NAT happening between the extension and the Asterisk server
3. Bypasses any VOIP blocking by your ISP
4. Provides secure access to the FreePBX web interface

How it works?

OpenVPN server software sits on the hosted FreePBX system allowing secure connections to the server. Traffic is encrypted between the OpenVPN client and the SysAdminMan FreePBX system. A certificate is generated for each OpenVPN client that connects to the server.

You can connect either an extension that supports OpenVPN directly (this could be a computer running OpenVPN with a softphone installed or some of the Yealink VOIP handsets support OpeNVPN directly) or, more commonly, connect an entire site via OpenVPN using a router with OpenVPN support.

It is possible to connect multiple sites to the same SysAdminMan system as long as each site uses a different LAN IP range

What router can you use?

You should be able to use any router that supports OpenVPN. I’ve tested with pfSense, Microtik (this is not the best choice as it only supports TCP connections, not UDP) and the OpenVPN Windows client. Maybe the simplest way though it to use the SysAdminMan custom firmware with the TP-Link 1043.

Using the TP-Link 1043 SysAdminMan firmware

There are 2 different ways you could use the TP-Link 1043 with the SysAdminMan firmware installed. The easiest way is to replace the existing broadband router and have all the routing via the TP-Link. That would look something like this –

That’s not always possible though. You may not want (or be able to) replace the existing router, certainly not while testing. What you can do is plug the TP-Link 1043 in to the existing router, so that it has an internet connection and then plug the phones in to the TP-Link 1043. The phone will then connect to the FreePBX/Asterisk system over OpenVPN, with the rest of the network unaffected –

How do you get this setup?

You can sign up for a hosted FreePBX server with OpenVPN installed at SysAdminMan FreePBX Hosting

Instructions for setting up your TP-Link 1043 with OpenVPN can be found here – https://sysadminman.net/blog/2012/vpnpbx-getting-started-3890

For more information about using a SysAdminMan system with OpenVPN please get in touch