Another way to keep our system secure is to enable a secure connection between the routers or firewalls in each endpoint. This connection can be done with a Virtual Private Network (VPN).

A VPN is an extension of a private network across the Internet enabling the communication between IP devices, as if they were connected to the private network. A VPN establishes a virtual point-to-point connection by using dedicated connections and encryption. One of the VPN's advantages, besides those already mentioned, is that we do not need to forward any TCP port, just one UDP port, generally 1194, to establish the connection between the sites. For the purposes of this recipe, we will use an add-on from Elastix called Easy-VPN, developed my Enlaza Comunicaciones (http://enlaza.mx).