D-Link DIR-456 - Connect a Telephone

7D-Link DIR-456 User Manual
Section 2 - Installation
Connect a Telephone
A standard RJ-11 jack on the back of the router allows you to connect a standard analog telephone for voice calls.
Simply plug the phone cable into the jack labeled FXS.
You can then use your handset to dial out as you typically would with a standard landline.
Your attached phone will also ring for any incoming voice calls.