FG (Feature Group)

A trunking arrangement between a local exchange carrier (LEC) and an interex-

change carrier (IXC) that enables end users to make long distance telephone calls using the IXC network.

Feature groups are designated A, B, C, and D.

• FGA: A line side access method in which the caller must dial a local telephone number for IXC access, then dial the long distance telephone number and a PIN or password.The IXC gains access to the customer through a subscriber line, rather than an interoffice trunk.

• FGB: The caller must dial a 950-XXXX telephone number and then dial the long distance telephone number and a PIN or password. In the 950-XXXX telephone number, the last four digits

correspond to the Carrier Identification Code (CIC) associated with each IXC.The 950-XXXX

number, which can be dialed as a local call from any geographic location, directs the call setup request to a centralized database that is used to direct the call to the nearest carrier retail outlet. An FGB connection is a trunk side connection commonly provided through an access tandem (AT)

switch, although it also can be provided through a direct trunking arrangement to a central office (CO) switch. An FGB connection is superior to an FGA connection.

• FGC: A traditional trunk side access service used prior to the implementation of equal access in 1984.Where it is available, which is almost universally, FGD has replaced FGC.

• FGD: An FGD trunk is sometimes referred to as an equal access trunk, as all carriers with FGD

trunks in a local exchange network are afforded equal access (1+ dialing) to the subscriber at designated central office exchanges (COs), whether via a direct trunking arrangement or through an access tandem (AT) switch. FGD provides the IXC with trunk side access, connecting the IXC as an integral part of the exchange carrier network. FGD includes presubscription to a subscriber-specific IXC and a 10XXX access code for use by end users in originating and terminating connections.

FGD also includes call supervision and the IXC receives calling party identification as part of the call setup, automatic number identification (ANI) data for billing purposes.

See also 10XXX, access tandem, ANI, call supervision, carrier, CIC, CO, equal access, IXC, LEC, line side, password, PIN, presubscription, trunk, and trunk side.

• Table E-3: European Digital Hierarchy: E-Carrier
• Table E-4: Frequency Spectrum: Band Designations, Nominal Frequency Ranges, Nominal
• Table E-4: Frequency Spectrum: Band Designations, Nominal Frequency Ranges, Nominal
• Table E-5: Endianess
• Table G-1: G-Series Recommendations
• Table H-1: H.320 Related Standards Recommendations
• Table H-2: SDTV Scanning Formats
• Table H-3: Notation Comparison
• Table H-4: Selected ITU-T H-Series Recommendations
• Table I-1: Frame Relay Implementation Agreements
• Table I-2: Index of Refraction (IOR)
• Table I-3: IPv4 Address Classes
• Table I-4: Selected ITU-T I-Series Recommendations
• Table I-4: Selected ITU-T I-Series Recommendations (continued)
• Table I-5: ITU-T Series Recommendations
• Table J-1: Japanese Digital Hierarchy: J-carrier
• Table L-1: Longitudinal Redundancy Check (LRC)
• Table M-1: International Morse Code
• Table O-1: OSI Reference Model Layers
• Table O-2: G.709 Line Rates and Corresponding SDH/SONET Line Rates
• Table P-1: Evolution of PBX technology
• Table P-2: Military and Aviation Phonetic Alphabet
• Table Q-1: Selected ITU-T Q-Series Recommendations
• Table R-1: Before and After: Bell Operating Companies (BOCs) and Regional Bell Operating
• Table R-1: Before and After: Bell Operating Companies (BOCs) and Regional Bell Operating