Cyclades User's Guide - Manual (Page 485)

469
number of 'probe' packets has been ignored by the client, the
server assumes the worst and the connection is closed.
The keep-alive timer provides the capability to know if the
client's host has either crashed and is down or crashed and
rebooted.
Telnet A terminal emulation program for TCP/IP networks such as the
Internet. The Telnet program runs on your computer and connects
your PC to a server on the network. You can then enter commands
through the Telnet program and they will be executed as if you
were entering them directly on the server console.
TFTP Trivial File Transfer Protocol. A simple network application
based on User Datagram Protocol (UDP). It is used to transfer
files from one computer to another.
TTY 1. In Unix, refers to any terminal; sometimes used to refer to the
particular terminal controlling a given job (it is also the name of a
Unix command which outputs the name of the current controlling
terminal). 2. Also in Unix, any serial port, whether or not the
device connected to it is a terminal; so called because under Unix
such devices have names of the form tty.
UDP User Datagram Protocol uses a special type of packet called a
datagram. Datagrams do not require a response; they are one way
only (connectionless). Datagrams are usually used for streaming
media because an occasional packet loss will not affect the final
product of the transmission.
U Rack Height Unit A standard computer rack has an internal width of 17 inches.
Rack space on a standard rack is measured in units of height (U).
One U is 1.75 inches. A device that has a height of 3.5 inches
takes 2U of rack space.
VPN Virtual Private Networking allows local area networks to
communicate across wide area networks, typically over an
encrypted channel. See also: IPsec.