Chapter 2 – Communication
Syed Shehryar Danish
, Networking
Key Terms
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, which can cover several buildings
in a single city, such as a university campus
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
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, can join LANs and to form a
WAN
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 wire connection
PAN Network that is centered around a person or their workspace
Syed Shehryar Danish
,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 meters
Node Device connected to a network
Peer-to-Peer Network in which each node can share its files with all the
other nodes. Each node has its own data an 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
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, the
addresses of the packet recipient and the actual data
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, which use routing logic so data packets
are sent from sending stations to receiving stations only by the
shortest route
Hybrid Network Network make 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, microwaves.
Implements IEEE 802.11 protocols
Syed Shehryar Danish
, 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, it randomly chooses another channel. It has a range up
to 100 meters
WPAN Wireless Personal Area Network. A local wireless network
which connects together devices in very close proximity;
typical devices would be a laptop, smartphone, tablet and
printer
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, insulation, copper mesh
and other insulation
Fiber Optic Cable Cable made up of glass fiber 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 usually associated with a MAC address set at the
factory
WNIC Wireless Network Interface Card/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
Syed Shehryar Danish
Syed Shehryar Danish
, Networking
Key Terms
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, which can cover several buildings
in a single city, such as a university campus
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
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, can join LANs and to form a
WAN
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 wire connection
PAN Network that is centered around a person or their workspace
Syed Shehryar Danish
,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 meters
Node Device connected to a network
Peer-to-Peer Network in which each node can share its files with all the
other nodes. Each node has its own data an 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
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, the
addresses of the packet recipient and the actual data
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, which use routing logic so data packets
are sent from sending stations to receiving stations only by the
shortest route
Hybrid Network Network make 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, microwaves.
Implements IEEE 802.11 protocols
Syed Shehryar Danish
, 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, it randomly chooses another channel. It has a range up
to 100 meters
WPAN Wireless Personal Area Network. A local wireless network
which connects together devices in very close proximity;
typical devices would be a laptop, smartphone, tablet and
printer
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, insulation, copper mesh
and other insulation
Fiber Optic Cable Cable made up of glass fiber 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 usually associated with a MAC address set at the
factory
WNIC Wireless Network Interface Card/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
Syed Shehryar Danish
