AS Level CS (9618) 2.1 Networking

2.1.1 Networking devices 2.1.2 Client-server and peer-to-peer networking models 2.1.3 Network topologies 2.1.4 Public and private cloud computing 2.1.6 Hardware requirements of networks 2.1.7 Ethernet 2.1.8 Bit streaming

ARPAnet

"Advanced Research Projects Agency Network."

WAN

"wide area network (network covering a very large geographical area)."

LAN

"local area network (network covering a small area such as a single building)."

MAN

"metropolitan area network (network which is larger than a LAN but smaller than a WAN

File server

"a server on a network where central files and other data are stored. They can be accessed by a user logged onto the network."

Hub

"hardware used to connect together a number of devices to form a LAN that directs incoming data packets to all devices on the network (LAN)."

Switch

"hardware used to connect together a number of devices to form a LAN that directs incoming data packets to a specific destination address only."

Router

"device which enables data packets to be routed between different networks (for example

Modem

"modulator demodulator. A device that converts digital data to analogue data (to be sent down a telephone wire); conversely it also converts analogue data to digital data (which a computer can process)."

WLAN

"wireless LAN."

(W)AP

"(wireless) access point which allows a device to access a LAN without a wired connection."

PAN

"network that is centred around a person or their workspace."

Client-server

"network that uses separate dedicated servers and specific client workstations. All client computers are connected to the dedicated servers."

Spread spectrum technology

"wideband radio frequency with a range of 30 to 50 metres."

Node

"device connected to a network (it can be a computer

Peer-to-peer

"network in which each node can share its files with all the other nodes. Each node has its own data and there is no central server."

Thin client

"device that needs access to the internet for it to work and depends on a more powerful computer for processing."

Thick client

"device which can work both off line and on line and is able to do some processing even if not connected to a network/internet."

Bus network topology

"network using single central cable in which all devices are connected to this cable so data can only travel in one direction and only one device is allowed to transmit at a time."

Packet

"message/data sent over a network from node to node (packets include the address of the node sending the packet

Star network topology

"a network that uses a central hub/switch with all devices connected to this central hub/switch so all data packets are directed through this central hub/switch."

Mesh network topology

"interlinked computers/devices

Hybrid network

"network made up of a combination of other network topologies."

Cloud storage

"method of data storage where data is stored on off-site servers."

Data redundancy

"situation in which the same data is stored on several servers in case of maintenance or repair."

Wi-Fi

"wireless connectivity that uses radio waves

Bluetooth

"wireless connectivity that uses radio waves in the 2.45 GHz frequency band."

Spread spectrum frequency hopping

"a method of transmitting radio signals in which a device picks one of 79 channels at random. If the chosen channel is already in use

WPAN

"wireless personal area network. A local wireless network which connects together devices in very close proximity (such as in a user's house); typical devices would be a laptop

Twisted pair cable

"type of cable in which two wires of a single circuit are twisted together. Several twisted pairs make up a single cable."

Coaxial cable

"cable made up of central copper core

Fibre optic cable

"cable made up of glass fibre wires which use pulses of light (rather than electricity) to transmit data."

Gateway

"device that connects LANs which use different protocols."

Repeater

"device used to boost a signal on both wired and wireless networks."

Repeating hubs

"network devices which are a hybrid of hub and repeater unit."

Bridge

"device that connects LANs which use the same protocols."

Softmodem

"abbreviation for software modem; a software-based modem that uses minimal hardware."

NIC

"network interface card. These cards allow devices to connect to a network/internet (usually associated with a MAC address set at the factory)."

WNIC

"wireless network interface cards/controllers."

Ethernet

"protocol IEEE 802.3 used by many wired LANs."

Conflict

"situation in which two devices have the same IP address."

Broadcast

"communication where pieces of data are sent from sender to receiver."

Collision

"situation in which two messages/data from different sources are trying to transmit along the same data channel."

CSMA/CD

"carrier sense multiple access with collision detection - a method used to detect collisions and resolve the issue."

Bit streaming

"contiguous sequence of digital bits sent over a network/internet."

Buffering

"store which holds data temporarily."

Bit rate

"number of bits per second that can be transmitted over a network. It is a measure of the data transfer rate over a digital telecoms network."

On demand (bit streaming)

"system that allows users to stream video or music files from a central server as and when required without having to save the files on their own computer/tablet/phone."

Real-time (bit streaming)

"system in which an event is captured by camera (and microphone) connected to a computer and sent to a server where the data is encoded. The user can access the data 'as it happens' live."