NetComm NB9 User Manual page 100

TCP/IP
Telnet
TFTP
TTL
twisted pair
upstream
USB
VC
VCI
VPI
100
Transmission Control Protocol/Internet Protocol The basic
protocols used on the Internet. TCP is responsible for di-
viding data up into packets for delivery and reassembling
them at the destination, while IP is responsible for deliv-
ering 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.
An interactive, character-based program used to access a
remote computer. While HTTP (the web protocol) and FTP
only allow you to download fi les from a remote computer,
Telnet allows you to log into and use a computer from a
remote location.
Trivial File Transfer Protocol. A protocol for fi le transfers,
TFTP is easier to use than File Transfer Protocol (FTP) but
not as capable or secure.
Time To Live A fi eld 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
fi eld by one. When the TTL reaches zero, the packet is
discarded.
The ordinary copper telephone wiring long used by tel-
ephone 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.
The direction of data transmission from the user to the
Internet.
Universal Serial Bus A serial interface that lets you con-
nect devices such as printers, scanners, etc. to your com-
puter by simply plugging them in. The My ADSL Modem is
equipped with a USB interface for connecting to a stand-
alone PC.
Virtual Circuit A connection from your ADSL router to your
ISP.
Virtual Circuit Identifi er Together with the Virtual Path
Identifi er (VPI), the VCI uniquely identifi es a VC. Your
ISP will tell you the VCI for each VC they provide. See
also VC.
Virtual Path Identifi er Together with the Virtual Circuit
Identifi er (VCI), the VPI uniquely identifi es a VC. Your ISP
will tell you the VPI for each VC they provide. See also
VC.
NB9/NB9W ADSL2+ VoIP Router
YML790 Rev1