Fast Link Pulse
A link pulse that encodes information used in the Auto-Negotiation Protocol. Fast link pulses consist of bursts of the normal link pulses used in 10BASE-T.

Fiber Optic Cable
A cable with a glass or plastic filament which transmits digital signals in the form of light pulses at wavelengths of 850 nm (10BASE-FL and 100BASE-SX) or 1300 nm (100BASE-FX).

Flow Control
The process of controlling data transmission at the sender to avoid overfilling buffers and loss of data at the receiver.

Forwarding
The process of moving frames from one port to another in a switching hub.

Frame
The fundamental unit of transmission at the data link layer of the OSI model.

Full-Duplex Operation
A communication method that allows simultaneous transmission and reception of data.