T

T1 Communications circuit provided by long-distance carriers for voice and data transmission (1.544 Mbps in U.S. or 2.054 Mbps in Europe); may be divided in 24 separate 64 Kb channels; E-1 in Europe.

T3 Digital communications circuit standard created by AT&T that operates at 44 Mbps.

TA Terminal Adapter

TB Transparent Bridging

Tank Circuit Ensures accurate signal tracking in token ring networks and prevents degradation of the signal; must be adjusted manually.

TCP/IP (Transmission Control Protocol/Internet Protocol) Set of protocols developed by the U.S. Defense Department's Advanced Research Projects Agency (ARPA) during the early 1970s. Its intent was to develop ways to connect different kinds of networks and computers. TCP/IP does not have the functionality that OSI provides.

TDM (Time Division Multiplexing) Technique where information from multiple channels may be allocated bandwidth on a single wire based on time slot assignment.

TDU topology database update

TE Terminal Equipment

Techinfo A common campus-wide information system developed at MIT.

TEI Text Encoding Initiative. An effort to create a large flexible SGML DTD for coding various types of written texts.

Telco Telco is a popular abbreviation for "telephone company." The RBOCs are a subset of all telcos.

Telnet A program which allows users to remotely use computers TCP/IP networks.

TEN-34 Trans-European Network at 34 Mbits/second. For more information see TEN-34 web page.

Terminal server Communications processor that connects asynchronous devices to a LAN or WAN through network and terminal emulation software.

TFTP Trivial File Transfer Protocol

Thinnet See Cheapernet.

3270 A dumb terminal for IBM* mainframes; generally, a terminal emulation standard for connecting to mainframe resources.

TIC Token Ring interface coupler

TN3270 Terminal emulation software that allows a terminal to appear to an IBM host as a 3270 model 2 terminal.

Token Control information frame, possession of which grants a network device the right to transmit.

TP (Twisted Pair) Cable consisting of two 18 to 24 AWG (American Wire Gauge) solid copper strands twisted around each other. The twisting provides a measure of protection from electromagnetic and radio-frequency interference.

TP-PMD twisted-pair/physical medium dependent

TR (Token Ring) As defined in IEEE 802.5, a communications method that uses a token to control access to the LAN. The difference between a token bus and a token ring is that a token ring LAN does not use a master controller to control the token. Instead, each computer knows the address of the computer that should receive the token next. When a computer with the token has nothing to transmit, it passes the token to the next computer in line.

Transaction Services Layer Layer 7 in the SNA architecture model.

Translation Bridging Bridging between networks with dissimilar MAC sublayer protocols.

Transcend An integrated management solution from 3Com that is based on groups of logically related devices and includes a powerful set of management tools.

Transparent bridging Bridging scheme preferred by Ethernet and IEEE 802.3 networks in which bridges pass frames along one hop at a time based on tables associating end nodes with bridge ports.

Transport Layer OSI layer that is responsible for reliable end-to-end data transfer between end systems.

TSA Technical Support Alliance (3Com and Novell)

TSR terminate-and-stay-resident

Twinaxial Cable contains two coaxial cable runs. Typically used in a IBM AS/400 environment and connects IBM 5250 to host.