Netcom NB9 - Manual (Page 79)

NB9/NB9W ADSL+ VoIP Router 79
YML790 Rev8
splitterless A type of DSL installation where no splitter is installed, saving the cost of a service call by the telephone company.
Instead, each jack in the home carries both voice and data, requiring a microfilter for each telephone to prevent
interference from the data signal. ADSL is usually splitterless; if you are unsure if your installation has a splitter, ask
your DSL provider. See also splitter, microfilter.
subnet A subnet is a portion of a network. The subnet is distinguished from the larger network by a subnet mask which selects
some of the computers of the network and excludes all others. The subnet’s computers remain physically connected
to the rest of the parent network, but they are treated as though they were on a separate network. See also network
mask.
subnet mask A mask that defines a subnet. See also network mask.
TCP
See TCP/IP.
TCP/IP Transmission Control Protocol/Internet Protocol The basic protocols used on the Internet. TCP is responsible for dividing
data up into packets for delivery and reassembling them at the destination, while IP is responsible for delivering the
packets from source to destination. When TCP and IP are bundled with higher-level applications such as HTTP, FTP,
Telnet, etc., TCP/IP refers to this whole suite of protocols.
Telnet An interactive, character-based program used to access a remote computer. While HTTP (the web protocol) and FTP
only allow you to download files from a remote computer, Telnet allows you to log into and use a computer from a
remote location.
TFTP Trivial File Transfer Protocol. A protocol for file transfers, TFTP is easier to use than File Transfer Protocol (FTP) but not
as capable or secure.
TTL Time To Live A field in an IP packet that limits the life span of that packet. Originally meant as a time duration, the TTL
is usually represented instead as a maximum hop count; each router that receives a packet decrements this field by
one. When the TTL reaches zero, the packet is discarded.
twisted pair The ordinary copper telephone wiring long used by telephone companies. It contains one or more wire pairs twisted
together to reduce inductance and noise. Each telephone line uses one pair. In homes, it is most often installed with
two pairs. For Ethernet LANs, a higher grade called Category 3 (CAT 3) is used for 10BASE-T networks, and an even
higher grade called Category 5 (CAT 5) is used for 100BASE-T networks. See also 10BASE-T, 100BASE-T, Ethernet.
upstream The direction of data transmission from the user to the Internet.
USB Universal Serial Bus A serial interface that lets you connect devices such as printers, scanners, etc. to your computer
by simply plugging them in. The My ADSL Modem is equipped with a USB interface for connecting to a stand-alone PC.
VC Virtual Circuit A connection from your ADSL router to your ISP.
VCI Virtual Circuit Identifier Together with the Virtual Path Identifier (VPI), the VCI uniquely identifies a VC. Your ISP will tell
you the VCI for each VC they provide. See also VC.
VPI Virtual Path Identifier Together with the Virtual Circuit Identifier (VCI), the VPI uniquely identifies a VC. Your ISP will tell
you the VPI for each VC they provide. See also VC.
WAN Wide Area Network Any network spread over a large geographical area, such as a country or continent. With respect to
the My ADSL Modem, WAN refers to the Internet.
Web browser A software program that uses Hyper-Text Transfer Protocol (HTTP) to download information from (and upload to)
web sites, and displays the information, which may consist of text, graphic images, audio, or video, to the user. Web
browsers use Hyper-Text Transfer Protocol (HTTP). Popular web browsers include Netscape Navigator and Microsoft
Internet Explorer. See also HTTP, web site, WWW.
Web page A web site file typically containing text, graphics and hyperlinks (cross-references) to the other pages on that web site,
as well as to pages on other web sites. When a user accesses a web site, the first page that is displayed is called the
Home page. See also hyperlink, web site.
Web site A computer on the Internet that distributes information to (and gets information from) remote users through web
browsers. A web site typically consists of web pages that contain text, graphics, and hyperlinks. See also hyperlink,
web page.
WWW World Wide Web Also called (the) Web. Collective term for all web sites anywhere in the world that can be accessed
via the Internet.