Asus Eee PC 4G Surf/Linux - Manual (Page 47)

ASUS Eee PC 4-11
Dial-up (Optional)
The telephone wire used to connect the Eee PC’s internal modem
should have either two or four wires (only two wires (telephone line
#1) is used by the modem) and should have an RJ-11 connector on
both ends. Connect one end to the modem port and the other to an
analog telephone wall socket (as found in residential buildings).
Telephone connector is
the smaller of the two.
Telephone Wall Jack
Telephone cables
with RJ-11 connectors
Telephone
connection is
optional
Only use analog telephone outlets. The built-in modem does not
support voltages used in digital phone systems. DO NOT connect
the RJ-11 to digital phone systems found in many commercial
buildings or else damage will occur!