Buitenlijn

Buitenlijn is a Dutch term used in telecommunications to describe the portion of a subscriber’s line that lies outside the building. It refers to the external path of the access network that connects the local exchange or street cabinet to the exterior of the premises. In practice, the buitenlijn is the outdoor segment of the connection, and it can consist of copper cables, fiber optic cabling, or other outdoor cabling installed on poles, in ducts, or in outdoor cabinets.

The buitenlijn is usually distinguished from the inside line (binnenlijn), which runs entirely within the customer’s property. The boundary between operator responsibility and customer responsibility is typically marked by a network interface device or demarcation point. When faults occur on the buitenlijn, technicians generally address issues in the exterior portion of the path and work toward the interior to locate the fault.

Technologies and configurations for the buitenlijn vary with the service. For traditional telephone services (PSTN) or broadband over copper (ADSL/VDSL), it comprises the outdoor copper path. For fiber-based services, the buitenlijn may include the outdoor fiber feeder and distribution network. Regardless of technology, the term remains in use to denote the external portion of the access path that connects the public network to the customer’s premises.

In summary, the buitenlijn is the external segment of a subscriber’s telecommunications line, important for service delivery, maintenance, and fault isolation, and it is commonly distinguished from the internal wiring within the property.