HP LaserJet Pro M1536dnf MFP SERIES - Manual (Page 125)

3. Remove the plastic insert from the "telephone" port (the port that is marked with the telephone
icon).
4. To connect an internal or external modem on a computer, plug one end of a telephone cord into
the product “telephone” port
. Plug the other end of the telephone cord into the modem “line”
port.
NOTE: Some modems have a second “line” port to connect to a dedicated voice line. If you have
two “line” ports, see your modem documentation to make sure that you connect to the correct “line”
port.
ENWW Set up fax 111