Can you use the same ethernet cord for both phone and internet?

Question

We have ethernet cord run all over the house. The way it is set up is that our phone comes in from the outside and the internet is run in to our home office. The outside phone wire is run to our attic, and there is also a wire connecting the office to the attic. We have every ethernet wire in the house running up in to the attic as well. We only have 1 ethernet port in each room. Some rooms we would like both internet and phone. Is this possible?

Answer 1

I don't see why you couldn't use your Cat 5 ethernet cable for both phone and internet, although I've never done it myself.

Ethernet only uses 4 of the 8 wires in the Cat 5 cable. You should be able to use any of the others for your phone. Each phone line requires 2 wires, so you could actually support two phone lines plus internet. The diagram in the link below shows the wire assignments. If you only have one phone line, I'd suggest putting it on pins 4 and 5, the two central positions. This might even allow you to use the same socket for phone and data (I'm not sure about this).

Just be sure that power isn't being distributed on the cable (power over ethernet, POE), as that uses some of the other wires.

Answer 2

SInce you need all the pairs of an ethernet cable for a data connection and 1 pair for phone service, no you would need to run at least 2 cables to have both.