When a service has a fault or is being installed, the carrier will generally make reference to the demarcation point. What the carrier doesn’t reference is what this is exactly and how to identify it.

Also known as a boundary point or network boundary point, a demarcation point is the physical point at which the public network of a telecommunications company ends and the private network of a customer begins. This is usually where the cable physically enters a building.

This spot varies depending on what type of dwelling you are in.

For a high-rise apartment or office building, the demarcation point will be the main distribution frame (MDF), which is generally in the basement. For a single house, the demarcation point will be either the first socket (generally in the kitchen) or a boundary box located on an outside wall. For some services, such as ISDN, there is a network boundary device (NBD) or network termination unit (NTU) as well. The carrier’s responsibility runs from the exchange to the applicable boundary point and, if applicable, includes the NTU. The wiring remains the customer’s responsibility.

It’s important to know where your demarcation point is in case anything ever goes wrong and you need a technician to investigate.

Scenario 1:

Analogue PSTN line in a free-standing house

In this situation, the carrier’s responsibility would cover the first socket in the house or a boundary box on the outside of the house. Traditionally the first socket is the kitchen socket. If the fault lies within other sockets or past the carrier box, you will need to arrange an ACMA accredited electrician to come out to investigate and repair.

Scenario 2:

ADSL service in an office building

When you are in an office building, the chances of the fault being within the internal wiring are much greater. The carrier’s responsibility is only up to the MDF, which is generally in the basement of the building. If the fault lies on the B side (customer’s side) within your sockets or the wiring in the walls, it will be up to you to organise an ACMA accredited electrician for repairs.

Having a better understanding of what a demarcation point is will help you save time if something goes wrong. Check out other articles in our Arrow blog to learn more about connectivity for your home or business and get more information about our great plans here.