What is the primary function of a SAP?

The primary function of a Service Access Point (SAP) is to serve as an interface for customer equipment (CE) devices to access network services. In this context, the SAP is a specific point in the network where the CE device connects to the service provider's network to utilize the offered services. By providing this access, the SAP facilitates the interaction between the CE and the larger networking infrastructure, enabling features such as routing, service quality, and protocol compatibility.

While options referring to the P device and MPLS tunnels may relate to other parts of network architecture, the specific role of the SAP is directly tied to connecting end-user equipment to the service provider's systems, highlighting its importance in delivering network services to customers.