I'm thinking of rewiring my phone wiring and installing a master filter at some point but at the moment I'm just trying to figure out which wires go where and in particular where my ETP is. My understanding is that the ETP is usually outside however looking around I cannot seem to find it anywhere. The other day I noticed this in the downstairs bathroom:

After removing the cover I can see it appears it is something to do with the phone wiring and on the outside wall of the bathroom there is a wire leading straight down into a small pipe, however there is no box or anything on the outside wall. Is this my ETP?
Thanks,
Daniel