Ive got a BT Home Hub 4 at home which i use to connect to a residential BT infinity connection c. 50mbps down, 10mbps up.
I want to configure a VPN gateway at home so that i can connect to devices on the local home network when im at my office.
Will the BT Home Hub 4 allow me to do this ?
The Home Hub doesn't have the capability of being a VPN server, however you can install and configure a device on your network to become a VPN server and set up the required port on your home hub to forward the IP packets to the device configured as a VPN server.
You could just use a Raspberry Pi as a cheap solution (a VPN server is just software that can be put on any device) or check the specs of various third party routers if you don't want a separate box. I believe ASUS routers have VPN server capability.
A number of the higher end third party routers appear to provide this e.g., Draytek 2860, Netgear D7000 and several TP-Link according to their Q&A Frequent questions about creating VPN connections.
Like others have said you can use a Linux or Windows powered devices (To use Windows built-in VPN server software, you may need a Enterprise, Server or Professional graded OS version).
If you don't want the hassle of installing and configuring the software then again you can get a Router with the software already installed and the majority of the set-up done. Also some NAS devices also offer to be a VPN Server too.
I personally use a raspberry Pi with open source software installed and configured.
Though be aware that if you are on ADSL then the bandwidth when connected to the VPN Server may be "little" as it will be limited to your upstream ADSL connection speed. For example when I do a speedtest from a device connected to the VPN Server it's about 0.28Mbps down and up. Though if you're on BT Infinity then there may be more bandwidth.