What is the juncture at which the CPE ends and the local loop portion of the service starts?
Ans) The demarcation or demarc is the juncture at which the CPE ends and the local loop portion of the service starts. The CO (Central Office) is the nearest point of presence for the provider's WAN service. The local loop or "last-mile" is the cabling that extends from the demarc into the WAN service provider's central office.