Lifetime Premier Subscriber
It contains the backup battery pack (top) and the converter from fiber to coax (left). I am unable to get into the right side where it looks like some Cat5 lines are coming in without actually unscrewing the entire thing from the wall. The following picture is not my specific box, so doesn't show those CAT5 lines coming into the right bottom, with coax line coming out into the coax connection on bottom right.
This does have the telephone test jacks (right) along with an ethernet hub input (left). But nothing is plugged into either.
My old house did have the box similar to what you posted along with the this same box in my garage. But new house just has this box in the garage and the rest of my wiring in my bedroom closet.
As I mentioned before, I already disconnected the telco line in the closet box and replaced it with the ooma line (far bottom right, white line -- again can't get the picture to post) to support the whole house and security system.
All the other lines connect to each of the rooms in the house. Not sure what else I can do.