I have a very old laptop I use as a home server and it has an RJ11 port. Apart from calling through and from with this connection as a landline, are there any other practical uses for this today?
22 Answers
That RJ-11 port almost certainly is just a POTS modem (Plain Old Telephone Service; analog dial-up voice landline modem).
Without a real telephone landline, and perhaps even without a simulator box that provides dial tone and ring voltage and DTMF touchtone decoding, you could probably hook it directly to another POTS modem via a telephone line cord (RJ-11 cord) and make a 33.6 kilobit per second (or less) connection over it, if you have a good serial comms app/tool and know your Hayes AT command set.
2RJ-11 jacks have one other use: Receiving and transmitting faxes.
Yes, faxing is 19th Century tech, but many doctors' offices and real estate firms still rely on it. Note: Faxing from a PC works best over a Plain Old Telephone Service ('POTS') line, will interfere with DSL service, and fails often if you your phone service is delivered over a digital carrier line.
