An organization that develops standards with the EIA (Electronics Industries Association) for
telecommunications technologies.
Telnet Standard terminal−emulation protocol in the TCP/IP protocol stack. It is used to perform terminal
emulation over TCP/IP via remote terminal connections, enabling users to log in to remote systems
and use resources as if they were connected to a local system.
Terminal Access Controller Access Control System Plus (TACACS+)
A security feature that uses an MD5 encrypted algorithm to enforce strict authentication controls. It
requires both a user name and password, allowing administrators to better track network usage and
changes based on user accounts.
thicknet coax
Thick cable (usually about .375 inch in diameter) most commonly found in the backbone of a coaxial
network.
thinnet coax
Cable that is thinner than thicknet (about .25 inch in diameter). It is commonly used in older bus
topologies to connect the nodes to the network.
token A frame that provides controlling information. In a Token Ring network, the node that possesses the
token is allowed to transmit next.
Token Ring
An IBM proprietary token−passing LAN topology defined by the IEEE 802.5 standard. It operates at
either 4− or 16Mbps in a star topology.
Token Ring adapters
Traditional ISA or Microchannel devices with 4− or 16Mbps transfer capability, used to connect
nodes to a Token Ring network.
topology
The shape or layout of a physical network and the flow of data through the network.
Transmission Control Protocol (TCP)
Part of the TCP/IP protocol stack. TCP is a connection−oriented, reliable data−transmission
communication service that operates at the OSI Transport layer.
Transmission Control Protocol/Internet Protocol (TCP/IP)
The suite of protocols combining TCP and IP, developed to support the construction of worldwide
internetworks. See Transmission Control Protocol and Internet Protocol.
Transmission Control Protocol/Internet Protocol (TCP/IP) socket
A socket, or connection to an endpoint, used in TCP/IP communication transmissions.
transmitThe process of sending data using light, electronic, or electric signals. In networking, this is usually
done in the form of digital signals composed of bits.
Transparent Bridging (TB)
A bridging type that uses the MAC address to make forwarding and filtering decisions transparent to
the sender and receiver interfaces. TB is used in Ethernet.
Transport layer
Layer 4 of the OSI Reference Model. It controls the flow of information.
Trivial File Transfer Protocol (TFTP)
A simplified version of FTP, allowing files to be transferred over a network from one computer to
another. It’s also used to install the Cisco IOS on an IOS−based switch, router, or Gigabit Switch
Router (GSR).
trunk link
A special type of VLAN connection. Unlike a user port, trunk links expect the device at the other end
of the connection to understand the inserted frame tags. Standard Ethernet and Token Ring cards do
not understand frame tags. Trunk links use an encapsulation method that allows them to carry the data
of more than one VLAN through the switched internetwork. Devices that support trunk links are
switches, routers, and some specialized NICs meant for servers.
twisted−pair
A type of cable that uses multiple twisted pairs of copper wire.
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