TRENDnet TEW-652BRP User Manual page 43

PPTP/L2TP with Dynamic IP
If connected to the Internet using a PPTP/L2TP (Dial-up xDSL) with dynamic IP
connection, enter the your Server IP, PPTP/L2TP Account and PPTP/L2TP Password,
if your ISP has provided you with a DNS IP address, enter it in the DNS field,
otherwise, leave it zero.