Introduction Networks Flashcards
Client
A device that enables users to access the network
Server
A device that provides services to clients
Circuit
All cables, radio links and devices in between that enables the communication between clients and servers
Switch
device that connect multiple devices to form a LAN
Router (what does it do?)
connects different networks together.
IP address
unique address to identify each device in a network as the receiver of a message. . Each device needs an IP address for sending, receiving information and connecting to other routers
LAN
Local Area Network. Group of client/server(s) that share a local circuit (connected w/ switches and cables or radio waves). Usually limited to a single building, or a single floor of a building
BN
Backbone Network. Connects multiple LANs using routers. Usually don’t contain clients or servers but serve as the circuit the connects the different LANs. Quite high speed as they need to handle all network traffic. Ex. different floors of a buildings. operated and owned by the organisation that uses them like Monash
MAN
Metropolitan Area Network. Can span several km. Connects LANs and BNs over different locations. Usually leased from a third party telecommunications company.
WAN
Connects networks over large distances. Ex. connecting MSA and Monash Malaysia.
Transmission rate
Measure of the speed of a connection
How many Mb in a GB?
1 GB x 8b = 8 Gb
8Gb x 1000b = 8000Mb
Ans : 8000Mb
Latency
The length of time for 1 bit of data to travel from a sender to a reciever
Presentation logic
part of the application that provides the UI
Application logic/ business logic
Defines how the application behaves (what should happen when a button is clicked)
Data access logic
Defines how the application manages its data (updating text docs when a user makes changes)
Data storage
Where the data is kept
Application architectures
the different methods which work can be split up between the client and the server
Server-based architectures
Presentation logic, application/business logic/ data access logic and data storage is performed by the server.
Advantages of server-based architectures
- Enables multiple user to access a single, main computer
- Any update is immediately available to all users
Dis-advantage of server-based architectures
- Upgrading the hardware means replacing a very expensive computer instead of inexpensive terminals
Client-based architecture
Only places the data storage on the server whilst the presentation, application and data access logic are performed by the client
Dis-advantages of client-based architecture
Incredibly difficult to make small changes to a file, as the entire file directory need to be downloaded over the network to your client. Puts enormous stress on the network, and even bigger problems when multiple user are attempting to gain access.
Advantages of client-based architecture
- Central file storage
- Allows for multiple users to work on the same file at the same time
- Central back-up machine
Client-server architecture
Client only performs the presentation and application logic. Server implements the data access and storage.
(Think queries)
Thin-client architecture
Client performs only presentation logic, and server implements application and data access logic and data storage
Mult-tier architecture
Tasks are further split because of millions of users. Dedicated servers are set for application logic and dedicated ones for the data access and storage
Peer-to-peer
Does not use servers at all. Connects multiple clients to each other
(Think file sharing apps)
