Computer hardware chapter 10

Internet appliance

A type of thin client that is designed to make it easy for a user to connect to the Internet, browse the web, use email, and perform other simple chores on the Internet.

network adapter

Part of the physical network inside a computer.

line-of-sight connectivity

A connection used by satellites that requires no obstruction from mountains, trees, and tall buildings from the satellite dish to the satellite.

fiber optic

A dedicated, leased line used for Internet access that uses fiber-optic cable from the ISP to a residence or place of business.

Network Attached Storage (NAS)

A device that provides multiple bays for hard drives and an Ethernet port to connect to the network. The device is likely to support RAID.

patch panel

A device that provides multiple network ports for cables that converge in one location such as an electrical closet or server room.

Bridge

A device that stands between two segments of a network and manages network traffic between them.

Switch

A device used to connect nodes on a network in a star network topology. It also segments the network to improve network performance by deciding which network segment is to receive a packet, on the basis of the packet's destination MAC address.

loopback plug

A device used to test a port in a computer or other device to make sure the port is working and might also test the throughput or speed of the port.

Power over Ethernet (PoE)

A feature that might be available on high-end wired network adapters that allows power to be transmitted over Ethernet cable to remote devices.

base station

A fixed transceiver and antenna used to create one cell within a cellular network.

RJ-11 jack

A phone line connection or port found on modems, telephones, and house phone outlets.

CDMA (Code Division Multiple Access)

A protocol standard used by cellular WANs and cell phones.

CAT-6

A rating used for UTP cables that has less crosstalk than CAT-5 or CAT-5e cables.

CAT-3 (Category 3)

A rating used for UTP cables that is less expensive than the more popular CAT-5 cables.

CAT-6a

A rating used for UTP cables that is thicker than CAT-6 and used by 10GBase-T (10-Gigabit Ethernet).

CAT-5 (Category 5)

A rating used for UTP cables.

SIM (Subscriber Identity Module) card

A small flash memory card that contains all the information a device needs to connect to a cellular network, including a password and other authentication information needed to access the network, encryption standards used, and the services that a subscription includes.

PAN (personal area network)

A small network consisting of personal devices at close range; the devices can include cell phones, PDAs, and notebook computers.

DSL (Digital Subscriber Line)

A telephone line that carries digital data from end to end, and is used as a type of broadband Internet access.

VoIP phone

A telephone that connects to a network and uses the VoIP TCP/IP protocol for voice communication over the network or the Internet.

Crimper

A tool used to attach a terminator or connector to the end of a cable.

punchdown tool

A tool used to punch individual wires from a network cable into their slots to terminate the cable.

wire stripper

A tool used when terminating a cable. The tool cuts away the plastic jacket or coating around the wires in a cable so that a connector can be installed on the end of the cable.

Broadband

A transmission technique that carries more than one type of transmission on the same medium, such as voice and DSL on a regular telephone line.

tone probe

A two-part kit that is used to find cables in the walls of a building.

wireless LAN (WLAN)

A type of LAN that does not use wires or cables to create connections but instead transmits data over radio or infrared waves.

ST connector

A type of connector used by fiber-optic cables and can be used with either single-mode or multimode fiber optic cables.

SC connector

A type of connector used by fiber-optic cables and can be used with either single-mode or multimode fiber-optic cables.

GSM (Global System for Mobile Communications)

An open standard for cellular WANs and cell phones that uses digital communication of data and is accepted and used worldwide.

Latency

Delays in network transmissions resulting in slower network performance.

mesh network

Each node (a computer or other device) that uses the network is responsible for sending and receiving transmissions to any other node to which it wants to communicate with a central point of communication.

Bandwidth

In relation to analog communication, the range of frequencies that a communications channel or cable can carry. In general use, the term refers to the volume of data that can travel on a bus or over a cable stated in bits per second (bps), kilobits per second (Kbps), or megabits per second (Mbps). Also called data throughput or line speed.

unshielded twisted pair (UTP) cable

The most popular cabling method for local networks and is the least expensive and is commonly used on LANs. The cable is made of twisted pairs of wires and is not surrounded by shielding.

Topology

The physical arrangement of the connections between computers in a network.

cable tester

Used to test a cable to find out if it is good or to find out what type of cable it is if the cable is not labeled.

RG-6 coaxial cable

A coaxial cable used for cable TV and replaced the older and thinner RG-59 coaxial cable.

LAN (local area network)

A computer network that covers only a small area, usually within one building.

half duplex

Communication between two devices whereby transmission takes place in only one direction at a time.

full duplex

Communication that happens in two directions at the same time.

Internet Service Provider (ISP)

A commercial group that provides Internet access for a monthly fee; AOL, Earthlink, and Comcast are large ISPs.

shielded twisted pair (STP) cable

A cable that is made of one or more twisted pairs of wires and is surrounded by a metal shield.

straight-through cable

A cable used to connect a computer to a switch or other network device. Also called a patch cable.

crossover cable

A cable used to connect two like devices such as a hub to a hub or a PC to a PC (to make the simplest network of all).

VoIP (Voice over Internet Protocol)

A TCP/IP protocol and an application that provides voice communication over a network. Also called Internet telephone.

cable Internet

A broadband technology that uses cable TV lines and is always connected (always up).

ISDN (Integrated Services Digital Network)

A broadband telephone line that can carry data at about five times the speed of regular telephone lines. Two channels (telephone numbers) share a single pair of wires.

coaxial cable

A cable that has a single copper wire down the middle and a braided shield around it.

enhanced CAT-5 (CAT-5e)

A improved version of CAT-5 cable that reduces crosstalk.

keystone RJ-45 jack

A jack that is used in an RJ-45 wall jack.

network multimeter

A multifunctional tool that can test network connections, cables, ports, and network adapters.

star network

A network configuration that uses a centralized device such as a switch or hub to manage traffic on the network.

Hub

A network device or box that provides a central location to connect cables and distributes incoming data packets to all other devices connected to it. Compare to switch.

WAN (wide area network)

A network or group of networks that span a large geographical area.

cellular network

A network that can be used when a wireless network must cover a wide area. The network is made up of cells, each controlled by a base station.

hybrid network

A network where a star network uses multiple switches in sequence, and the switches form a bus network.

fully connected mesh topology

A network where each node connects to every node on the network.

LC (local connector) connector

A newer type of connector used by fiber-optic cables and can be used with either single-mode or multimode fiber optic cables.

MAN (metropolitan area network)

A type of network that covers a large city or campus.

ring network

A type of network where nodes form a ring.

ad hoc mode

A type of physical arrangement of the connection between computers where each wireless computer serves as its own wireless access point and is responsible for securing each connection.

network interface card (NIC)

An expansion card that plugs into a computer's motherboard and provides a port on the back of the card to connect a computer to a network. Also called a network adapter.

RG-59 coaxial cable

An older and thinner coaxial cable once used for cable TV.

bus network

An older topology whereby all computers are connected in a sequential line.

fiber-optic cable

Cable that transmits signals as pulses of light over glass or plastic strands inside protected tubing.

twisted-pair cabling

Cabling, such as a network cable, that uses pairs of wires twisted together to reduce crosstalk.

4G (Fourth Generation)

The ability to use a cell phone to browse the web, stream music and video, play online games, and use instant messaging and video conferencing.