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Telecommunications

      
   
Testing, Repairing and Installing Home telephone Wiring - Locating the Demarcation Point

Locating the demarcation point

When planning where to put your telephone jacks, the best place to start is the demarcation point between your wiring and the wiring of the telephone company:

demarcation point

Your telecommunications company maintains the wiring up to a demarcation point.  The demarcation point is typically at the “Network Interface Device” (“NID”). This device is usually located on the outside of your home.  If you have an older home or have a home alarm system, the demarcation point may be found at a “Network Interface Jack” which is inside your home, at the point where the telephone wiring enters your home.

Note: If you subscribe to telephone service from your cable television provider or from an alternative provider (like a VoIP provider), the information contained here may not be helpful to you and could harm your equipment.  Attempting to work on these other systems may result in a loss of service.

You may also have different components if you have a “fiber to the home” application.  Further, if you are attempting to install a digital subscriber line (DSL) for broadband Internet service, this information may not be sufficient. 

If you do not fully understand which system you have or you are not confident in your ability to work on the components of your system (regardless of whether it is depicted in this information or not), you should contact your service provider to install new components or troubleshoot existing ones.

If you cannot locate either a NID or a Network Interface Jack, it may be helpful to contact the telephone company to determine where your demarcation point is located. 

If you live in a multi-unit or multi-tenant building, you may want to contact the property manager or condo association to determine where these devices are located in your building.  Your local service provider may also be able to help you determine where the demarcation point is. You will also need to contact your landlord to determine whether they are responsible for repair of the telephone inside wire on their premises.