Which term is commonly used to denote the boundary between provider and customer networks in a building?

• A. Demarcation point (Demarc)
• B. Service boundary
• C. Customer interface
• D. Boundary device

Answer: (A)

The boundary between the provider’s network and the customer’s network is called the demarcation point. This term marks where the service provider’s responsibility ends and the customer’s responsibility begins, and it’s the physical point of interconnection in a building—often where the network interface device sits. Up to and including the demarc, the provider handles the network side; beyond it, the customer handles inside wiring and customer premises equipment. While a boundary device may exist at that spot, the standard term used to denote the boundary itself is the demarcation point.