Can I Use a Telephone Jack for Ethernet in My Apartment?

Yes, it's technically feasible to use a telephone jack for Ethernet, but the performance might not be the best. You'll need some special devices like a 2-wire Ethernet converter or Home PNA adapters to make it work. Typically, these aren't super cheap, and you're usually looking at a maximum bandwidth of around 100 Mbps at best.

Powerline adapters could indeed work well for your setup. They let you use your existing electrical wiring to connect your PC. However, keep in mind that they can sometimes be slow, especially if there are many devices on the same circuit.

Honestly, your quickest bet is to replace the phone wiring with CAT5e or similar. It's straightforward if it's a direct connection and not tangled up with other phone lines. Overall, it’s just not worth trying to force Ethernet through a phone line.

If it's a standard telephone jack (RJ11), then unfortunately, it's not capable of supporting Ethernet. It's designed for phone signals, which operate differently than Ethernet. But if somehow it's a 4P4C jack, theoretically, you could get some speed, but it's not reliable for a decent connection.

It sounds like you have just one telephone jack, right? Typically, even if there is another telephone jack in your apartment, they aren't usually set up for Ethernet. A better solution might be to use powerline adapters to connect different rooms. Just make sure that the electrical circuits for both rooms are on the same breaker panel; otherwise, you might run into some connection issues.