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T1
T1 is a digital carrier facility used to transmit a DS-1 formatted digital signal at 1.544 Mbps. It can be divided
into 24 separate DS0 channels at either 56 or 64 kbps.
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Table
One or more rows of cells on a page used to organize the layout of a page or arrange data systematically. You can
place anything in a table cell, including text, images, and forms.
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Tape Back-Up
Tape Back-Up is the process of copying all the data and programs of a computer system on magnetic tape. On tape,
data is stored sequentially. When retrieving data, the tape is searched from the beginning of tape until the data
is found.
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Target frame
The name of a frame in which to display the target page of a hyperlink. Typically, a hyperlink from one frame of
a frames page will supply as its target frame another frame of the frames page.
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TCP (Transmission Control Protocol)
TCP is an Internet networking software that controls the transmission of packets of data over the Internet. Among
its tasks, TCP checks for lost packets, puts the data from multiple packets into the correct order, and requests
that missing or damaged packets be resent. Computers must run TCP to communicate with Web servers.
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TCP/IP Model
TCP/IP Model is sometimes called the DOD model since it was designed for the department of defense. It is also
called the internet model because TCP/IP is the protocol used on the internet. The TCP/IP model does not exactly
match the OSI model.
Generally, TCP/IP is described using three to five functional layers. To describe TCP/IP based firewalls more precisely,
we have chosen the common DoD reference model, which is also known as the Internet reference model.
The four network layers defined by TCP/IP model are as follows.
Layer 4 - Application/Process Layer
Consists of applications and processes that use the network. |
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Layer 4 - Application
End-user applications reside at this layer. Commonly used applications include NFS, DNS, arp, rlogin, talk, ftp,
ntp and traceroute. |
Layer 3 - Transport Layer (host-to-host)
Provides end-to-end data delivery services. |
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Layer 3 - Transport
Handles communication among programs on a network. TCP and UDP falls within this layer. |
Layer 2 - Internetwork Layer
Defines the datagram and handles the routing of data. |
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Layer 2 - Network
This layer is used for basic communication, addressing and routing. TCP/IP uses IP and ICMP protocols at the network
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Layer 1 - Physical Layer
Netwrok access layer consists of routines for accessing physical networks. |
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Layer 1 - Link
This layer defines the network hardware and device drivers. |
This model is based on the three layers defined for the
DoD Protocol Model in the DDN Protocol Handbook, Volume 1. These three layers are as follows: Network access
layer, Host-to-host transport layer and Application layer. An additional layer, the internetwork layer,
has been added to this model. The internetwork layer is commonly used to describe TCP/IP.
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TCP/IP Stack
To properly use the TCP/IP protocol, PCs require a TCP/IP stack. This consists of TCP/IP software, sockets
software (such as WINSOCK.DLL for Windows machines), and hardware driver software (known as packet drivers). Windows
95 comes with Microsoft's own built-in TCP/IP stack, including version 1.1 of Microsoft's WINSOCK.DLL and packet
drivers.
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TDM (Time-Division Multiplexing)
TDM provides a way of transmitting multiple channels on a single transmission line by connecting terminals, one
at a time, at regular intervals, interleaving bits (Bit TDM) or characters (Character TDM) from each terminal.
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Term
The first of a pair of paragraphs formatted as a definition list entry. The second paragraph is the definition.
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Terminator
1. Terminator is a device that provides electrical resistance at the end of a transmission line. Its function is
to absorb signals on the line, thereby keeping them from bouncing back and being received again by the network.
2. Most commonly found in relation to a SCSI chain, this functions to prevent the reflection or echoing of signals
that reach the ends of the SCSI bus. Usually terminators are hardware circuits or jumpers.
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Thicknet
Thicknet is built with a thick coaxial cable that is used with a 10Base5 Ethernet LAN.
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Thinnet
Thinnet is built with a thin coaxial cable that is used with a 10Base2 Ethernet LAN.
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TIFF (Tagged Image File Format)
TIFF is a high-resolution, tag-based image format. TIFF is used for the universal interchange of digital images.
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Token
Token is a special packet that contains data and acts as a messenger or carrier between each computer and device
on a ring topology. Each computer must wait for the messenger to stop at its node before it can send data over
the network.
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Token Ring
Token Ring is a network protocol developed by IBM in which computers access the network through token-passing.
Usually uses a star-wired ring topology.
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Topology
There are two types of topology: physical and logical.
Physical topology of a network refers to the configuration of cables, computers, and other peripherals.
Logical topology is the method used to pass the information between workstations.
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Transceiver (Transmitter/Receiver)
Transceiver is a device that receives and sends signals over a medium. In networks, it is generally used to allow
for the connection between two different types of cable connectors, such as AUI and RJ-45.
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Transport Layer
Transport Layers use TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) protocols. Ensures properly
sequenced and error free transmissions.
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Tree Topology
Tree Topology is a LAN topology similar to linear bus topology, except that tree networks can contain branches
with multiple nodes.
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Twisted Pair
Twisted Pair is a Network cabling that consists of four pairs of wires that are manufactured with the wires twisted
to certain specifications and is available in shielded and unshielded versions.
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