Cyclades User's Guide manual Telnet, Rack Height Unit

	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.
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