Glossary-14
explicit congestion notification
A mechanism to indicate the existence of congestion. The notification bits in
the frame relay header are either forward (FECN) or backward (BECN). The
process could take place simultaneously on multiple DLCIs in response to
congestion on a given line or node, thus notifying multiple sources and
destinations.
See also
FECN and BECN.
excess burst size
See
Be.
fax, facsimile
Transmission of images (written, typed, or drawn material) through a
voice/fax channel.
FCS, frame check sequence
The standard 16bit cyclic redundancy check used for HDLC and frame relay
frames. The FCS detects errors occurring in the bits of the frame between
the opening flag and the FCS, and is only effective in detecting errors in
frames of 4096 octets or smaller.
See also
CRC.
FECN, forward explicit congestion notification
Indicates congestion downstream or toward the destination.
See also
Explicit
Congestion Notification.
FEATUREPAK cartridge
The cartridge containing the operating firmware for MICOM products. The
FEATUREPAK contains a specific release of software from the factory and
cannot be field upgraded. Contrast with FlashPak cartridge.
Federal Communications Commission (FCC)
A Government board that has the power to regulate all U.S. interstate
communications systems as well as all international communications systems
that originate or terminate in the U.S.
FF, form feed
A control character used to tell a terminal device to go to the top of the next
page.
flash bank
A memory bank on the Integration unit's Communications Control Module
(CCM) FlashPak, the Universal Voice Module (UVM), on an Integration
Router Module, or on the 3K base module (CCM and voice side) into which
new software is downloaded and from which software is loaded into the unit's
RAM.
