Operation Manual

Glossary
SIP Software Release 6-0-0
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ethernet A common, 10Mbps local area network technology invented by
Xerox Corporation at the Palo Alto Research Center. Ethernet is a best-effort
delivery system that uses CSMA/CD technology. Ethernet can be run over
thinwire coaxial cable (10BASE2), thickwire coaxial cable (10BASE5), twisted
pair cable (10BASET), or fibre optic cable.
F
FCS Frame check sequence. Bytes added to a frame so that the integrity of the
frame may be checked. Typically the bytes are a CRC of the data in the
frame.
FXS Foreign Exchange Service. A network-provided service in which a
telephone in a given local exchange area is connected, via a private line, to a
central office in another, i.e., “foreign”, exchange, rather than the local
exchange area’s central office. A FXS line is normally connected to a
standard telephone, fax or modem.
file transfer The process of copying of a file from one computer to another
over a computer network. See anonymous FTP, FTP.
File Transfer Protocol See FTP.
firewall A system or combination of systems that enforces a boundary
between two or more networks.
flag A program-readable indicator that can be used to signal an event or a
state, or provide simple data values (e.g. TRUE/FALSE, ON/OFF, use option
X). For example, in the HDLC data link protocol, the bit pattern 01111110 is
used to flag the beginning and end of a frame.
FLASH A new memory technology which combines the nonvolatile features
of EPROMs with the easy in-system reprogramming of conventional volatile
RAM. See EPROM.
flow control Control of the rate at which devices inject packets into a
network, usually to avoid congestion. Flow control mechanisms can be
implemented in hardware and/or software, at various protocol layers, and
with varying complexity.
frame A frame is a data link layer “packet” which contains the header and
trailer information required by the physical medium. That is, network layer
packets are encapsulated to become frames. See datagram, encapsulation,
packet.
FTP File Transfer Protocol. The TCP/IP standard, high-level protocol for
transferring files from one computer to another over a network. FTP is also