Editing Demarcation point (section)

==== <span id="Demarc extension">Demarcation point extension</span> ====
[[File:Demarc Extension Single Segment.jpg|thumb|left|upright=1.6|Demarcation point extension]]

A '''demarcation point extension''', or '''demarc extension''' is the transmission path originating from the interface of the access provider's side of a  demarcation point within a premises and ending at the termination point prior to the interface of the edge [[Customer-premises equipment|Customer Premises Equipment]] (CPE). This may include in-segment equipment, media converters and patch cords as required to complete the circuit's transmission path to the edge CPE.  A demarc extension is more correctly termed "Service Interface Extension", and may also be referred to as inside wiring, extended demarc, circuit extension, CPE cabling, riser cabling or DMARC extension.<ref>{{cite web|url=http://www.integratednetworkcable.com/cabling-and-network-installation/demarc-extension-services |title=Demarc Extension Services Nationwide T1 Circuit Extensions |publisher=Integratednetworkcable.com |access-date=2016-04-28}}</ref>

A demarc extension became an important factor to consider in a building's telecommunications infrastructure after the 1984 [[Bell System Divestiture|deregulation of AT&T]] as well as the supplemental FCC rulings of 1991, [[Telecommunications Act of 1996|1996]] and 1997. Preceding these rulings, the Bell System Companies held a monopoly and did not allow an [[interconnection]] with third party equipment. The [[incumbent local exchange carrier]]s (ILEC) and other local access providers are now mandated by federal law to provide a point where the operational control or ownership changes. This separation between the local access provider and the end user/subscriber is called the demarcation point within a facility (typically a short distance from the minimum point of entry). This then becomes the responsibility of the end user to extend their service to the CPE location within a facility to provide connectivity for service, requiring a service interface extension, or otherwise called a demarc extension.