D-Link DWC-1000 User Manual - Page 225

Wireless Controller User Manual Chapter 8. IPsec / PPTP / L2TP VPN  Th e fo llo win g feat u re is av ailab le u p o n licen s ed act iv at io n o f VPN / Firewall feat u res fo r t h e s y s t em. A VPN p ro v id es a s ecu re co mmu n icat io n ch an n el ("t u n n el") b et ween t wo g at eway co n t ro ller o r a remo t e PC clien t . Th e fo llo win g t y p es o f t u n n els can b e creat ed :  Gateway-to-g ateway VPN: t o co n n ect t wo o r mo re co n t ro ller t o s ecu re t raffic b et ween remo t e s it es .  Remote Cl i ent (clien t -t o -g at eway VPN t u n n el): A remo t e clien t in it iat es a VPN t u n n el as t h e IP ad d res s o f t h e remo t e PC clien t is n o t kn o wn in ad v an ce. Th e gateway in this cas e acts as a res ponder. Remo t e clien t b eh in d a NA T co n t ro ller: Th e clien t h as a d y n amic IP ad d res s an d is b eh in d a NA T co n t ro ller. Th e remo t e PC clien t at t h e NA T co n t ro ller in it iat es a VPN t u n n el as t h e IP ad d res s o f t h e remo t e NA T co n t roller is n o t kn o wn in ad v ance. T h e g ateway Op t io n p o rt act s as res p o n d er. 223