So in order to make my server more secure, I keep it behind a pfSense appliance. I use IP filtering to reduce my online availability to only our remote office locations (all in NYC). I get this impending feeling people will want to access the server via their cell phones and check voicemail via the portal offsite. So I was thinking of some kind of reverse proxy with an authentication and a token as opposed a VPN which just is not practical with the variety of devices people use. What are other people doing? Does anyone have a similar situation? What should I google?