Cyclades ACS48 Network Hardware User Manual


 
Glossary
AlterPath Console Server User Manual 153
been ignored by the client, the server assumes the worst and
the connection is closed.
The keepalive 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
Terminal Server A terminal server has one Ethernet LAN port and many
RS-232 serial ports. It is used to connect many terminals to
the network. Because they have the same physical interfaces,
terminal servers are sometimes used as console access
servers.
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.