said by uphillclimb:If the alarm system is the first device behind the NID, then I suppose I would have to put the splitter between the NID and the alarm system.
That is correct.
said by uphillclimb:Well, from looking at the NID on the outside of my house, it's got a standard RJ11 jack, so I'm assuming a convenient plug-in install would work, if not for the alarm system.
No it is not that simple. The fact that you have an NID with RJ-11 test jack is good (some still have the old line protectors without test jack) but as I said before there are different makes and models and not all will fit POTS splitters (my NID didn't and therefore I have two separate outdoor POTS splitters mounted next to it).
The advantage of having an NID that can house the POTS splitter is that you don't need to mount an additional outdoor enclosure next to the NID with wires between the two. A downside is that it limits you in the choice of POTS splitter to those made specifically for your NID. Having the POTS splitter installed inside the NID does not eliminate any of the wiring requirements (just makes it easier due to the close proximity with the existing wires). POTS splitters are made in many different styles with all sorts of different terminations (many have screw terminals for the wires, some have RJ-11 jacks and others have IDC punch-down terminals).
POTS splitters and microfilters perform similar functions and in principle it is possible to use a microfilter instead of a splitter. The two issues are:
- a microfilter is designed for the load of a single device (phone, fax, etc.) while the POTS splitter is designed to handle the load of all devices in your home.
- the filter characteristics of a POTS splitter are generally far better then those of a microfilter.
What you definitely cannot do is trying to put a microfilter in front of your alarm system with your existing home wiring. Since currently your modem is after the alarm system you would block all the DSL signals and get no (or extremely poor) connectivity.
You have:
phone1 --- filter ---\
phone2 --- filter ----*---(inhouse wiring)--- alarm --- NID
modem ---------------/
In this (common) scenario the DSL signal spreads throughout the entire inhouse wiring with the alarm system as well as reflections at unused outlets causing some interference.
You want:
phone1 ----*---- (inhouse wiring) --- alarm --- (voice) splitter (network) --- NID
phone2 ---/ |(data)
modem -----------------(new twisted pair cable) ---------/
In the ideal scenario you split the analog voice portion of the phone line from the DSL signals as soon as possible after the NID (but definitely before the alarm system). This keeps the DSL signal out of your old inhouse wiring and creates a clean path for those signals from the NID to your DSL modem.
Depending on your specific situation and how your home was originally wired you may not have to run a new twisted pair cable. If your inhouse wiring is Cat 3 or Cat 5 twisted pair cable and all outlets are wired as separate runs you should be able to identify the one going to the DSL modem and reuse it.