Glossary and Abbreviations
Issue 5 January 1998 GL-23555-230-024
FAS
Facility-associated signaling
FAT
Facility access trunk
FAX
Facsimile
FCC
Federal Communications Commission
FEAC
Forced Entry of Account Codes
feature
A specifically defined function or service provided by the system.
feature button
A labeled button on a telephone or attendant console used to access a specific feature.
FEPFront-end processor
FICFacility interface codes
fiber optics
A technology using materials that transm it ult r awide b an d ele ctro ma g net ic li ght-frequency ranges
for high-capacity carrier systems.
fixed
A trunk allocation term. In the fixed allocation scheme, the time slots necessary to support a
wideband call are contiguous, and the first time slot is constrained to certain starting points.
flexible
A trunk allocation term. In the flexible allocation scheme, the time slots of a wideband call can
occupy noncontiguous positions within a single T1 or E1 facility.
floating
A trunk allocation term. In the floating allocation scheme, the time slots of a wideband call are
contiguous, but the position of the first time slot is not fixed.
FNPA
Foreign Numbering-Plan Area
foreign-exchange (FX)
A CO other than the one providing local access to the public telephone network.
foreign-exchange trunk
A telecommunications channel that directly connects the system to a CO other than its local CO.
foreign numbering-plan area code (FNPAC)
An area code other than the local area code, that must be dialed to call outside the local
geographical area.
FRL
Facilities Restriction Level
FX Foreign exchange