{{Short description|Characteristic of interfaces that allows operators to support transmission}}
In [[telephony]], '''interface functionality''' is the characteristic of interfaces that allows them to support [[transmission (telecommunications)|transmission]], [[switching]], and [[Signalling (telecommunication)|signaling]] functions identical to those used in the enhanced services provided by the [[common carrier|carrier]].
As part of itsIn [[comparably efficient interconnectiontelephony]] (CEI) offering, the'''interface carrierfunctionality''' mustis makethe availablecharacteristic standardized [[hardware]] and [[software]]of interfaces that areallows ableoperators to support [[transmission (telecommunications)|transmission]], [[Telephone exchange|switching]], and [[Signaling (telecommunications)|signaling]] functions identical to those used in the enhanced services provided by the [[common carrier|carrier]].
As part of its [[comparably efficient interconnection]] (CEI) offering, the carrier must make available standardized [[telephone network]]ing hardware and [[software]] interfaces that are able to support transmission, switching, and signaling functions identical to those used in the enhanced services provided by the carrier.
