Networking Flashcards
Explain what is a LAN(Local Area Network).
A network of computing devices connected within a small geographical area, typically within the same building, such as a home, school or office.
Small number of connections and close proximity of devices allow for faster data transfer than other networks.
Explain what is a WAN(Wide Area Network).
A network of computing devices covering a large-scale geographical area, typically across multiple geographical locations.
Generally consists of multiple smaller networks such as LANs or MANs(Metropolitan Area Network).
Not limited to a single geographical location and can span long distances via long-range transmission media such as telephone lines, fibre optic cables or satellite links unlike LAN.
Can be either private or public.
Wan uses more expensive and high-speed technology than a LAN.
What is the intranet?
It is a private network based on internet (TCP/IP) protocols and services to share a company’s information with its employees.
Can have websites, FTP servers, interactive client/server applications.
But a firewall surrounds an intranet to fend off unauthorised access.
It provides greater speed, security and is platform independence.
A company’s internetwork is composed of many different networks.
What is the use for IP Addressing and DNS (Domain Name Server)?
The purpose of an IP address is to handle the connection between devices that send and receive information across a network. The IP address uniquely identifies every device on the internet. Without one, there’s no way to contact them. (Range from 0.0.0.0 to 255.255.255.255)
The DNS translates human readable domain names (for example www.amazon.com) to machine readable IP addresses (for example, 192.0.0.1).
How is data transmitted in a packet-switching network?
Data are sent in terms of packets (a unit of data). Headers are attached to identify their order. Packets travel through the network from node to node. They intermingles with packets of other conversations on the shared network. The packets then reassembled at the end.
Example: Computer to Computer communications postal system. Where the packets are like letters and is mixed with other letters.
It allows for the network to be fully utilised.
How is data transmitted in a circuit switching network?
Establish a dedicated communication path through different network nodes between the source and destination. There are physical links between nodes. On each link, there is a logical channel dedicated to the connection. Data from the source transmitted through the dedicated link as soon as possible (aka quickly). Hence, there is no delay between reception and retransmission.
Example: The Telephone system, where there is a direct line between the 2 telephones dedicated to that connection. Users hear each other as they speak.
It is expensive as it does not allow people to share your connection.
What is the Application Layer?
It sends and receives data for particular applications.
Protocols: HTTP, HTTPS, FTP
. It provides a service for the end user to send a request and get a response back from the server.
What is the Transport Layer?
It provides communication session management between computers. It defines the level of service and status of the connection.
Protocols: TCP, UDP
TCP: Responsible for breaking up data into segments, reassembling them at the other end, resending data lost in transit, resequencing data.
What is the Internet Layer?
Routes packets across networks.
Packages data into IP datagrams, containing source and destination address information.
Used to forward datagrams between hosts and across networks.
IP packets are handed over to a data link protocol, such as Ethernet, for the actual, physical transmission to the next node in the network path.
Protocols: IP
Where IP Addresses are used at.
What is the Link Layer?
Specifies how data is physically sent through the network.
Including how bits are electrically signalled by hardware devices that interface directly with a network medium.
Where MAC Addresses are used at.
Advantages of Packet Switching Network over Circuit Switching Network.
It is more efficient than circuit switching as data packets are able to find the destination without the use of a dedicated channel. It reduces lost data packets because packet switching allows for resending of packets.
Advantages of Circuit Switching Network over Packet Switching Network.
It decreases the delay that user experience for real time communication like before and during phone calls. This is because the call is done with a steady bandwidth, dedicated channel and consistent data rate. Its packets are always delivered in the correct order.
What is Circuit Switching?
It establish a dedicated communication path through different network nodes between the source and destination.
There is a physical links between nodes. No delay between reception and retransmission.
What is Packet Switching?
There is no dedicated transmission capacity along a path.
Data are sent in terms of packets(a unit of data)
Headers are attached to identify them.
Packets travel through the network from node to node.
Intermingled with packers of other conversations on the shared network.
Packets reassembled at the end.
Explain the advantages of a client-server network compared to a peer-to-peer network.
- Client server has centralised management of the shared data resulting in better security as it can determine who have access rights and what kind for the shared data. As all the information is stored on a server, it is easier to secure data and setting of permissions on the server. Client-server network is more secure as it contains a list of usernames and passwords for authentication. On a peer-to-peer network, data can be distributed across many computers that is acting as both a client and a server so it is much harder to ensure data security across many computers.
- Since it is a centralised system, it can be easy to add more resources and clients.
- In a client-server network, each peer has only has to service local processing demands while requests for data are rooted to a dedicated server. Resources of P2P are divided between local activities and servicing network requests from other peers, this makes allows the clients to be faster in CS than P2P as less processing power is required for clients in client-server.
