Chapter 5 Flashcards
PAN
Personal area network; Connects personal devices in a very short range with or without cables (Ex. Phone to headset)
LAN
Local area network; Connects personal computers within a limited area (Ex. School computer lab)
MAN
Metropolitan area network; Public high-speed network capable of transmission within 50 mile range (Ex. Local internet service providers)
WAN
Wide area network; Covers a large geographical area and several smaller networks (Ex. The Internet)
Shared resources
Hardware, software, and data made available for authorized network users to access
Node
Each connection point on a network containing a computer, peripheral, or other device
NIC
Network interface card; Special circuitry in a system board required to connect to a LAN
Networked peripheral
Device that contains network circuitry to directly connect to a network
NAS
Network attached storage; Storage device that directly connects to a network
Network device
Any electronic device that broadcasts network data, boosts signals, or routes data to its destination
Router
A type of network device that acts as a central distribution point for getting data to its destination
Communications channel
Physical path or a frequency for signal transmissions
RJ45 connector
At the end of a network cable
Optical fiber cable
Composed of many strands of thin glass tubes that send data at the speed of light
Bandwidth
Transmission capacity of a communications channel
Broadband
High-bandwidth communications systems (Ex. Cable TV & DSL)
Narrowband
Communications systems with less capacity (Ex. Dial-up)
Communications protocol
A set of rules for efficiently transmitting data from one network node to another
Handshaking
The process by which two computers on a network negotiate their communications protocols
Packet
Parcel of data that is sent across a computer network
Circuit switching
Establishes a dedicated, private link between two devices, such as a telephone
Packet switching
Divides a message into several packets that can be routed independently to their destination
MAC address
A unique number assigned to a network interface card when it is manufactured
IP address
Series of numbers used to identify a network device
DHCP
Dynamic Host Configuration Protocol; Protocol designed to automatically distribute IP addresses
Advantages of LAN
- LANs enable people to work together
- Sharing networked software can reduce costs
- Sharing data on a LAN can increase productivity
- Sharing networked hardware can reduce costs
- Sharing an Internet connection can be cost-effective and convenient
- Sharing networked hardware can provide access to a wide range of services and specialized peripheral devices
Disadvantages of LANs
- Malfunctions limit access to data
- LANs are vulnerable to unauthorized access
- LANs are vulnerable to malicious code
What can communications protocols do?
- Divide messages into packets
- Affix addresses to packets
- Initiate transmission
- Regulate the flow of data
- Check for transmission errors
- Acknowledge receipt of transmitted data
How does data travel over a network?
- Source –> (Encoded data) –> 2. Transmitter –> (Signal) –> 3. Communications channel –> 4. Receiver –> (Decoded data) –> 5. Destination
What kind of signals can travel over computer networks?
Electromagnetic signals
- Digital signals: limited set of frequencies
- Analog signals: any value in a range of frequencies
How can a network detect if a signal has been corrupted?
Detects and reestablishes voltages that have errors
Ex. +3 volts corrected to +5 volts when the only options are -5 volts and +5 volts
Ethernet
A wired network technology that is defined by IEEE 802.3 standards; standard for wired connections in local area networks
Ethernet adapter
Can be installed if a computer has no Ethernet port
RF signals
Radio waves
Transceiver
A combination of a transmitter and a receiver that sends and receives radio waves
Microwaves
Electromagnetic signals that behave differently than radio waves
- Can be aimed in a single direction
- More carrying capacity
- Cannot penetrate metal objects