I'm not sure if this is the right section but I have the Cox Cable internet, phone, and cable service bundle. When my service was set up they gave me a digital voice modem that connects my phone as well as my internet. I am planning on getting a new modem but the one that I'm looking at doesn't have a phone jack. I was wondering if there was an adapter with two ethernet ports that would also adapt an ethernet connection to a phone connection so that my phone service would still work. If this is possible could anyone recommend one? Sorry if this is hard to understand but if you have any questions, just ask me.
You can't use phone ports and ethernet ports interchangeably, they aren't the same technology - it's not like audio where different connectors are just different ways of wiring the same connector. To be able to use your phone you need to buy a new modem with a phone connector on it, or have a second phone socket installed at your premises.
Actually, I have another question. I have seen couplers with two ethernet ports and a phone jack. Could it work if I put one ethernet cable from my modem into a port, connect one ethernet cable from my computer to the other port, and plug it into the phone jack?
Once again, ethernet and phone are completely separate signals. This will only work if the modem you use has the hardware inside to convert a phone signal into a digital form for ethernet - if it could do that, it would probably just have a phone port on it anyway.
Faster? In the vast majority of cases the service provider decides the speed of the connection, not the modem.
Well a newer Motorola modem has been released that uses DOCSIS 3.0 and people have said that their speeds have been faster that their service provider "decides" as you say.
"Your Mileage may very" - check what connection speed you're getting now compared with what your ISP says you should be getting. if it's any less, a new modem will probably make no difference.