Instruction Manual

102
GigaX3112 Series Layer 3 Managed Switch
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.
Trunk
Two or more ports are combined as one virtual port, also
called as Link Aggregation.
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.
VLAN
Virtual Local Area Network