Note: Actual back panel of your Internet Gate model might differ from image above. Certain ports might be missing on cheaper models.
ADSL connector, used as WAN port for connecting Internet Gate to the Internet using an ADSL/ADSL2/ADSL2+ connection.
FXO connector, used to connect Internet Gate to global telephone network to make and receive ordinary telephone calls.
Not used by your Internet Gate.
FXS connectors allowing connection of up to 5 analogue telephones per port, converting them into IP-phones.