Networking - General Flashcards
What is a LAN
LAN stands for Local Area Network
LAN refers to a collection of devices and computers connected together in a physical location of small geographical area
Devices and computers are connected through wifi or Ethernet cables
What is a computer network?
Computer network is a group of computers or devices which uses the same set of communication protocol to share data over digital connections
What is WAN?
WAN stands for Wide Area Networks
WAN refers to a collection of LANs that are connected to each other over large geographical area.
These LANs are connected to each other through the internet
What are the three network types?
Intranet
Extranet
Internet
What is the Intranet and its purpose?
Intranet refers to a local private network which
- excludes outsiders access
- accessed only from an organisation premises OR
- through a virtual private network (VPN)
Purpose: Intranet is usually used at workplaces where a lot of data sensitive files are required to be shared securely
What is the Extranet and its purpose?
Extranet is a private network which
- extranet extends intranet to specific external users as it
- allows approved external users to access some parts of the organisation’s intranet
- without compromising the confidentiality of the internal network
Purpose: Extranet allows for secure sharing of data with external parties , thus is often used in B2B (business to business) communications
What is the Internet and its purpose?
Internet is a global system of interconnected computer networks which
- uses the internet protocol suites (TCP/IP) to communicate between networks and devices
What are the two different types of data transmission techniques used in networks?
Circuit Switch Networks
Packet Switch Networks
How does a circuit switch network work?
- A dedicated communication path is established between source and destination
- Data is sent out in continuous streams of packets
- Each packet will follow the same route to destination,
- and the returning data follows the same route back to the source
- Packets at destination and source are reconstructed in the order they arrive
How does a packet switching network work?
- In packet switch networks, packets does not follow a dedicated path
- Data is split up into packets with its own ID number (ID number is to keep track of the order of packets)
- Packets also had headers to determine its destination and method of transmission
- Packets follow different routes to destination and back to the source
- Since packets may arrive out of order, packets are reconstructed based on the sequence of their ID number
State 3 advantages of Circuit Switch networks
- A: Lower chance of data corruption
R: Information is sent in a continuous stream, thus there is no need to store and retransmit the data from intermediate nodes, hence the chances of data corruption is lowered - A: Transmission of data requires lower overhead, thus more memory efficient…
R: Since data packets arrives in order, there is no need to store and transmit additional information such as ID number as data can be reconstructed in the order packets arrive. - A: Lower chance of data loss
R: Since a dedicated path with guaranteed bandwidth is established for data transmission, transmission characteristics such as latency remains stable when the data is transfered.
State 3 disadvantages of Circuit switched networks
- D: Large set up time due to call setup delay
R: Both the sender and receiver must be ready before transmission can occur - D: Circuit switched network can cause other transmission to be negatively affected
R: Dedicated path causes the total bandwidth available to other transmissions to be lowered, thus less available resources for other transmissions, hence higher chances of congestion in the network - D: Potential high disruption in data transmission
R: (ONLY IF) the network is prone to disruptions, the whole transmission is interrupted and thus data will not be able to be sent at all
State 3 advantages of packet switch networks
- A: Less delay in setup time; data transfer can begin instantaneously
R: Only sender is required to be ready before transmission begins - A: More reliable data transmission
R: If any segments of the network is distrusted, data packets can be routed around the disruption and still reach its destination - A: Fully utilise the network
R: Congested segments of network can be bypassed if other segments are available, thus maximise bandwidth to fully utilise the network
State 3 disadvantage of packet switch networks
- D: Data taransmission requires larger overhead; longer transmission as more data to transfer
R: Additional data such as ID number and packet header is required to be transferred alongside the data itself
R: Additional bits have to be added for error detection and correction - D: Increased likelihood of data corruption
R: Data packets travel from one free node to the next free node, where data is stored and retransmitted at every node, this increases the chances of data corruption - D: Might be inefficient in applications which require real time communications (streaming, video calling etc)
R: In packet switching networks, there is a higher chances of packet loss, which can lead to disruptions in applications which require data to be transferred and received continuously
More time is taken when the lost packet is retransmitted
Name the two network architecture models
Client - Server model
Peer to peer model
