D-Link DSL-2500U User Manual page 45

Section 3 – Configuration
PPTP
To access the PPTP Setting window, click the PPTP button in the Advanced Setup directory.
To set up Point-to-Point Tunnel Protocol, tick the Enable check box, enter
the appropriate information in the fields offered, and then click the
Save/Apply button when you are finished.
D-Link DSL-2500U User Manual 45