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Why Supply Your Own Demarc Box?

In recent years, these demarc boxes have come to serve another purpose; they allow you to disconnect all inside wiring and test the outside line directly by plugging in a modular phone. The phone company will tell you to do this before sending out a repair person to determine who's fault the problem is. If the fault is on your side of the wiring, you'll pay for the service call.

Ordinarily, you would let the telephone company install their own demarc box. But here are a few reasons you may not have thought of why it makes a lot of sense to provide and/or install your own.

• Provide for more (and cleaner) expansion than the phone company would. Chances are, the phone company will install a small, two-line demarc box. If you later add lines and need more than two...they'll place another demarc box near the first for the additional line(s). This can get quite ugly and confusing over the years. (At one point, I had three demarc boxes, each a different model and style on the side of my house. Internal wiring had to be stripped, with each pair running to a different demarc box. This exposed the individual twisted pairs to the environment and allowed moisture into the jacket of the Cat 5 cables.)
• Provide better "protectors" than the phone company would. The "telco access only" side of demarc boxes hold a device called a protector. One per installed phone line. Both wires of the outside line and the inside wiring connect to the protector, as well as a good earth ground. The protector is a surge and over-voltage protection device that is intended to protect your equipment from phone company problems, phone company equipment from your problems, and all equipment from environmental (i.e.: lighting) problems. Better protectors = better protection. This is, however, the one part that the phone company is most likely to replace with their own version.
• Allows completion of inside wiring before phone lines are installed. Inside telephone wiring is usually completed long before the phone company brings in their lines. Thus the inside wiring installer can't really finish his installation all at one time...he must come back after the phone company installs their lines just to connect the inside wiring to the demarc box. If he installs his own demarc box, he shouldn't have to come back to connect the phone lines: Even if the phone company replaces his box, surely they will at least re-attach the inside lines!
• You can place the demarc box exactly where you want it. You should have a pretty good idea of where the utilities (phone & cable) are coming into the house. This wall is where the phone company will place their demarc box. Often it is an outside wall, often near the power meter. But there is still quite a bit of lattitude in the exact placement of the box. Maybe you want it down low so it will be behind the bushes, or off to one side or the other. Or maybe the inside wiring needs to come out in a particular place due to the wall's inner structure. If you supply your own demarc box, you can mount it wherever you want (as long as it is reasonably accessible and in the right "general" area.)
• Security Perhaps you wish to maintain a slightly higher level of security on your phone lines. If you are mounting your own demarc box, you can route the inside wiring in through knock-outs in the back of the demarc box so that the wires are not exposed to external tampering. Plus, these demarc boxes can be padlocked.
• Lastly, they're not very expensive. All the above reasons, plus this one, make it a no-brainer in our minds. Even if the telephone company refuses to connect to your demarc box, they can replace it with their own and are more likely to give you a similar unit, mounted in the same location, so you'll get what you wanted anyway!