Wall receptacle for CAT5e

I recently bought an apartment and I couldn't find any phone plugs. Later on I found two receptacles that look like a receptacle for a phone jack, one in each of the bed rooms.

However when I plugged in the phone that's using RJ45, it didn't fit.

Not only it didn't fit, the receptacles (both of them) seem to be filled with some sort of semi liquid gel.

When I opened the wall module to inspect, the cable connecting to it is labeled CAT5e. However out of the bunch of wires inside the cable jacket, only two strands were used to connect to that jack.

Is this for internet services may be DSL?

What are those gel inside the jack?

 

Do the apartments have a shared distribution panel or do each have their own NID?

 

An RJ-45 plug is what is found on network cables. It is 8 pins. It will not be found on a standard phone.

A standard phone jack is an RJ-11.... which is actually a 6 pin jack but only 4 pins are used. Even though it's 4 pins..... only 2 are needed for a standard phone.

The only time you would see an RJ-45 plug on a phone is if it were a Voip type phone that connected to a computer network.

The gel is found in Ma Bell installed jacks. It's just an anti corrosion type gel.