I had to get a new DSL modem. Unfortunately, I ordered it online and never thought about how many phone line ports it had, and I got one with only one port. I only have one phone jack in my apartment, and since I rent, installing another isn't an option. (Nor is exchanging the modem; getting this one to connect me to the internet was beyond frustrating and I'm NOT going through that again!) So now I can hook up the internet or hook up my phone, but not both. The modem, though, has four ethernet ports, only one of which is being used.

It appears I can get a splitter so that I can plug both the phone and the modem into the same jack, or I can get an ethernet adapter so that I can plug my phone into the modem (which is plugged into the jack). Am I misunderstanding something? Which is better?

I guess I'm worried that if I get the splitter, my DSL quality/speed will be degraded, and I'm worried that if I get the adapter and plug the phone into the modem, it won't actually work and I'll have bought an adapter for no reason.

DOES that work? Is that what they're for? Do my worries about using a splitter have merit, or will the splitter work fine? Is there an even better solution that I haven't thought of yet?

Clearly I'm not good at this kind of stuff, so any advice will be appreciated.

You do not plug your phone into the ethernet adaptor. If you get a splitter what your going to need is a filter. Then you should be fine. You can call your dsl service provider if they can give you one. It attatches to the "phone" line. That is all you need to do.