To establish a VPN connection to a certain location (such as your office), you will need a VPN gateway at that location. This gateway could be a hardware VPN gateway device (see our compatibility page for compatible devices and setup guides).
The VPN gateway needs to be connected to the Internet (e.g. to a DSL modem or similar), preferably with a static IP address or it should be capable of using a service like DynDNS.org to map its dynamic IP to a hostname. Configuration is easiest if the VPN gateway is also the router (default gateway) of its network. If the VPN gateway is not the router of its network, a suitable routing setup may be necessary for traffic over the VPN to be routed correctly.
Configuration details can be found in the configuration guides for specific devices.