In telephony, the demarcation point is the point at which the telephone company network ends and connects with the wiring at the customer premises. A demarcation point is also referred to as the demarc, DMARC, MPOE, or minimum point of entry.
Reference:
http://en.wikipedia.org/wiki/Demarcation_point
Reference:
http://en.wikipedia.org/wiki/Demarcation_point