DIY phone junction box for cable telephone service
We recently moved into a house that had been gutted and rehabbed by the previous owners. As part of the renovation all of the phone/cable wires coming into the house were removed (there are actually still 3 old phone NIDs attached in various places to the outside of the house, but no service line attached and no wiring leading into the structure, just empty boxes). New cable and phone drops were installed inside and the wiring run through the walls and terminated at a single point outside of the house (all were "home runs" for both cable and phone). We had Comcast out yesterday to re-run the service line and hook up for phone/cable/internet; we do not plan on getting dedicated phone service since we can get it through the cable company.
Here is the rub: since cable phone service is only active downstream from the modem, and all of the phone lines we have are "home runs" from the jacks to the common termination point outside, we actually need to tie them all together to get phone service throughout the house. Basically just bridge all of the lines off of the one that is downstream from the modem. Seems simple enough on the surface, but I'm having problems putting the pieces together.
Can we just reuse one of the existing NIDs/phone junction boxes (at least two of which still have the punch down blocks in them) and treat the interior phone line attached to the modem as the "service" line in this case (again, this line runs from the jack next to the modem and is terminated outside with the other phone lines)? Or would it be better to buy a new punch down and connect everything inside? Of the 4 phone lines we need to connect, 3 of them are routed to a common exit point in the basement; the 4th line runs outside on the first level so I would need to consider routing it back inside in that case. We likely won't want a phone in that location, so that may be a moot point.
One complicating factor: we may be getting an alarm installed. Does that affect our choice in junction boxes for the phone "service"? I'm guessing for security we'd want it all inside. The smallest punch down I can find is a 66, but that seems like overkill for essentially splicing 8 lines together (4 phone cables x 2 lines per cable).