User Guide
Page 39
... and applications of the ZyXEL Device. Models ending in "7" denote a device that works over T-ISDN (UR-2). 1 Only use firmware for high-speed Internet browsing and making LAN-to-LAN connections to remote networks. Models ending in "3" denote a device that works over ISDN (Integrated Services Digital Network). Refer to the P-662HW-Dx series only...
... and applications of the ZyXEL Device. Models ending in "7" denote a device that works over T-ISDN (UR-2). 1 Only use firmware for high-speed Internet browsing and making LAN-to-LAN connections to remote networks. Models ending in "3" denote a device that works over ISDN (Integrated Services Digital Network). Refer to the P-662HW-Dx series only...