ZyXEL Communications Prestige 643, User Manual

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Prestige 643 ADSL Router
X Glossary
TCP Transmission Control Protocol. The major transport protocol in the Internet suite of
protocols providing reliable, connection-oriented full-duplex streams.
TCP/IP Filter Rules TCP/IP filter rules allow you to base the rule on the fields in the IP and the upper
layer protocol, e.g., UDP and TCP headers.
Telco The generic name for telephone companies throughout the world which encompasses
RBOCs, LECs and PTTs.
Telnet The virtual terminal protocol in the Internet suite of protocols. Allows users of one
host to log into a remote host and act as normal terminal users of that host.
Terminal A device that allows you to send commands to a computer somewhere else. At a
minimum, this usually means a keyboard and a display screen and some simple
circuitry.
Terminal Software Software that pretends to be (emulates) a physical terminal and allows you to type
commands to a computer somewhere else.
TFTP Trivial File Transfer Protocol is an Internet file transfer protocol similar to FTP (File
Transfer Protocol), but it is scaled back in functionality so that it requires fewer
resources to run. TFTP uses the UDP (User Datagram Protocol) rather than TCP
(Transmission Control Protocol).
UDP UDP is a connectionless transport service that dispenses with the reliability services
provided by TCP. UDP gives applications a direct interface with IP and the ability to
address a particular application process running on a host via a port number without
setting up a connection session.
URL (Uniform Resource Locator) URL is an object on the Internet or an intranet that
resides on a host system. Objects include directories and an assortment of file types,
including text files, graphics, video and audio. A URL is the address of an object that
is normally typed in the Address field of a Web browser. The URL is basically a
pointer to the location of an object.
Virtual Connection
(VC) A link that seems and behaves like a dedicated point-to-point line or a system that
delivers packets in sequence, as happens on an actual point-to-point network. In
reality, the data is delivered across a network via the most appropriate route. The
sending and receiving devices do not have to be aware of the options and the route is
chosen only when a message is sent. There is no pre-arrangement, so each virtual
connection exists only for the duration of that one transmission.
WAN Wide Area Network s link geographically dispersed offices in other cities or around
the globe. Just about any long-distance communication medium can serve as a WAN
link, including switched and permanent telephone circuits, terrestrial radio systems