Zhone Technologies IMACS-200 - Manual (Page 283)

Glossary -9
Errored Seconds. The number of seconds for which BRI port has detected a NEBE or FEBE
greater than zero (0).
ESF
Extended Superframe (24-frame sequence for a T1 line; consists of two superframes)
ESS
Electronic Switching System
E&M
Earth and Magnetic, or recEive and transMit. The signaling leads on inter-switch voice
connections.
E&M port
An E&M voice port for this system.
ETS1
European Telecommunications Standards Institute
F4
Four-frame multiframe structure used in T1 signals.
FAS
Frame Alignment Signal
FCC
Federal Communications Commission
FDL
Facility Data Link, consists of every other framing bit of an extended T1 superframe. The FDL
is used to convey performance data, line test/loopback status, and other parameters for an
ESF-framed T1 line. The FDL rate is 4 kHz.
FE1
Fractional E1
FEBE