D-Link DIR-857 User Manual page 102

Section 4 - Security
5. Enter the same security key or passphrase that is on your router and click
Ok.
It may take 20-30 seconds to connect to the wireless network. If the connection
fails, please verify that the security settings are correct. The key or passphrase
must be exactly the same as on the wireless router.
D-Link DIR-857 User Manual 97