Term

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Asynchronous Transfer Mode. A media access method using the star topology and fiber-optic cables. Data transmits at 155 Mbps and higher. ATM is good for video, voice and teleconferencing applications.

The amount of data that can be pushed through a link in unit time. Usually measured in bits or bytes per second.

A network "relay" which reads, buffers and sends data to relay it from one data link to another, but makes the two data links appear as one to levels higher than the data link layer.

Physically connects network devices together, serving as a conduit for information travelling from one computer to another. Types of cabling include coaxial cable, twisted-pair cable and fiber-optic cable.

A set of conjoined computers that can share storage devices, peripherals, and applications. Networks may be connected directly by cable connection, or indirectly by telephone lines or satellites, and can be part of a small-office system or a global web of numerous other networks.*

Dynamic Host Configuration Protocol

In a database management system, the limited range of valid values for a field. For example,  a domain might be restricted to numeric characters, as in the case of telephone numbers. On Transmission Control Protocol/Internet Protocol (TCP/IP) networks, such as the Internet, a domain is a group (large or small) of connected computers. Within a domain, there might be subdomains.

On the Internet, domains are denoted by a three-letter code. Some of the largest, most common domains are as follows:

• .edu- educational institution;
• .gov-government site, other than state- funded universities;
• .com - commercial site;
• .mil - military site;
• .net - network site;
• .org- nonprofit or private organization.

In addition, most countries have domain names. Sub-domains range from fairly broad categories, such as a university, a military base, or a large corporation, to small intranets and single computers. A domain can also refer to a group of workstations on a network.*

Domain Name Server. A distributed hierarchical scheme which breaks down the full name of a University host into three components. The host administrator chooses the first part of the name. The second is fixed by the name of your department. The third part of the name is the same for all University hosts and specifies that the host is operated by U.Va.

Device Driver. A program that allows a hardware peripheral, known as a device, to communicate with a computer.*

The most widely used local-area network (LAN) media access method.*

Ethernet cable refers to any cable that carries data using the Ethernet LAN media access method. Types of cable that can carry ethernet include: 10bT, co-axial and fiber optic.

A piece of computer hardware that allows computers to exchange information by sending electrical signals through Ethernet cable.

Fiber Distributed Data Interface (FDDI) is a standard developed by the American National Standards Institute (ANSI) for fiber-optic networks. FDDI uses fiber-optic cable to transmit data in bursts of light at speeds far faster than conventional networks. Rates of 100 megabits per second are possible over distances of two kilometers or less.*

A computer on a local-area network (LAN) that provides network users access to shared data and program files.*

File Transfer Protocol. A standardized, text-based method of transferring files from one computer to another**.

A device that connects two or more network devices so they can communicate. In other words, a point on the network where multiple devices are connected to each other.*

Internet Protocol. A protocol designed by DARPA, Defense Advanced Research Projects Agency, to connect heterogeneous networks.

Internet Protocol Address. The address of a computer on a Transmission Control Protocol/Internet Protocol (TCP/IP) network. IP addresses are written as four groups of up to three digits each separated by periods. An example is 119.183.115.11.*

Local Area Network is a group of computers, usually in one building or office, physically connected in a manner that lets them communicate and interact with each other.*

Defines how computing devices access the network cables and send data.  Some examples include, Ethernet, Fast Ethernet and FDDI.

Network Basic Input/Output System was developed by IBM as an interface specification for access to network services.

Netbios Extended User Interface. Original PC networking protocol designed by IBM for LanManager, later adopted by Microsoft.

The physical configuration of a network that determines how the network's computers are connected. Common configurations include the bus, star and ring topologies.

Open System Interconnection. A network model in which communications are divided into seven layers. Each layer performs a specific task or tasks and builds upon the preceding layer until the communication is complete.

A network setup where the server is non-dedicated, meaning it is also a workstation. Every computer acts on its own by storing files and accessing peripherals (such as printers) and can see every other computer on the network, with the proper access privileges. This formation is used primarily in smaller networks of less than a dozen computers.*

A set of rules and procedures for exchanging data between computers on a network or through the Internet. Protocols usually includes information on error checking, data compression, and sending and receiving messages. Also called an access method.*

An instrument that increases a signal's strength so it can be transmitted and received over a greater distance without loss of quality.*

The part of a communications network that receives transmissions and forwards them to their destinations using the shortest route available. Data may travel through multiple routers on their way to its destination.*

Transmission Control Protocol/Internet Protocol. A language governing communication between all computers on the Internet. TCP/IP are a set of instructions that dictates how packets of information are sent across multiple networks.**

Terminal emulation in which a user is connected to a remote host using an Internet account as if the user were directly connected to the host. For example, typing telnet hostname connects a user to a host named "hostname." After a prompt for a user name and password, the session continues as if the user was at a terminal connected to the host, though the user is actually connected to another site, using the Internet to connect to the host.*

A type of network topology where computers are connected to one another in the shape of a ring.*

Wide Area Network is a communications network that covers a wide geographic area, such as state country. A LAN (local area network) is contained within a building or complex, and a MAN (metropolitan area network) generally covers a city or suburb. The Internet is an examples of a WAN.

Blue.unix.
virginia.edu

The name of the UNIX cluster.

Home Directory Service

A Central repository for individual electronic file storage that can be accessed anywhere (http://www.itc.virginia.edu/homedir/).

Home Directory

Personal working directory of your blue.unix.virginia.edu account.

Clear text passwords

Unencrypted sequences of characters to allow you to connect to other machines on a network.

Drive mapping

Assigning a letter to designate a particular network connection or drive.

Quotas

The maximum amount of data that you can store in your home directory at any given time.

Quota Limits

Undergraduate students=25MB, Graduate students=50MB, Faculty and Staff=75MB

Snapshot

An uneditable copy of all the files and directories in your home directory taken at a particular moment. Snapshot directories are exact copies of the directories saved on the Home Directory Server at that moment. Snapshots are used for backups to restore lost, corrupt or deleted files.

SysTray

The "System Tray", located in the far right hand corner of the Task bar in the Window 9x/NT opearating system, contains a group of icons representing applications and utilities that startup when the computer is booted.

Timeout

Occurs when mouse movement is not detected within the specified time limits. Options are provided to reconnect or terminate (cancel) the connection to the Home Directory Service.

Timeout Limits

Personal desktop computers=4 hours of mouse inactivity, ITC computer labs=15 minutes of mouse inactivity