Characteristics of LAN/WAN, Client-server/peer-to-peer + thick/thin client

“Describe the characteristics of a LAN”

• Devices connected over small geographical area

• Uses private-owned/dedicated (company) infrastructure

“Describe the key features of a peer-to-peer network”

• All computers have equal status

• Each computer provides access to resources and data/data is distributed

• Computers can communicate and share resources

• Each computer is responsible for its own security

“Describe drawbacks of peer-to-peer networks”

No central management of security

• Only as secure as weakest computer on network

• Each computer is at risk from viruses from other computers

No central management of back-up

• If the data from a computer is not backed up, it is lost to all

No central management of files

• Difficult to maintain consistency

• Each computer may have different software from the others

Individual computers may respond slower

• Because they are being accessed by other computers

In order to share files, all computers involved must be switched on

• Files may not always be available

“Justify LAN or WAN for school setting up network”

LAN

• Small geographical area

• Doesn’t use internet to transmit within building

“Benefits of dividing a network into subnetworks by subnetting the LAN”

• Improves security

• Reduces congestion

• Allows extension of the network/devices attached

• Aids day-to-day management

• Improves performance

“How does a subnet mask differentiate network ID and host ID”

• Network ID is where subnet mask is 255 (11111111)

• Host ID is where subnet mask is 0 (00000000)

“Benefits of connecting computers to LAN”

• Allows sharing of files/data // allows communication between the devices

• Allows the sharing of resources e.g. hardware/software

• Allows central management e.g. backup, security

“Characteristics of LAN”

• Covers a small geographical area

• The infrastructure is privately owned // not controlled by external organisations

“Describe what is meant by a thick-client model”

• The server performs minimal/some processing for the client

• The clients do most of their processing/work independently // most of the resources are installed locally

“Describe what is meant by a thick-client model”

• The client computer performs minimal/some processing

• Data is not stored on computer but on server

• Client computer is reliant on access to server to function

“Identify differences between a WAN and a LAN (local area network)”

• WAN covers large geographical area, LAN covers a small geographical area

• WAN connections are virtual, LAN connections between devices are usually physical

• WAN has low data transfer rates, LAN has high data transfer rates

• Ownership of WAN is private or public, ownership of LAN is private

• WAN harder to implement security, LAN more secure

• WAN may use non-dedicated hardware, LAN hardware is dedicated

“Describe the roles of different computers in a thin-clients, client-server model”

• Server performs all processes required by the task and/or data storage

• Clients only sends requests to the server and displays the returned results

“Describe the roles of the different devices in a client-server model - allow customers to access their accounts using an application to download onto devices”

• Use server in banks, receives and processes requests

• Client sends requests to server, waits and outputs response

“Thin-client characteristics + description of use (software to mark exam papers)”

Data is not stored on the client computer:

• Exam papers are stored on the server and not the examiner’s computer

Client computer is reliant on access to server

• Examiners cannot mark if their device cannot access the server

Client computer heavily reliant on network/internet connection:

• Marking software will not operate without network/internet access

Client computer requires few local resources/memory

• Examiners can use devices with low resources and marking software will still function

Client computer performs minimal functions/processes

• The marking software transmits requests, server responds and sends response to the user

“Characteristics of a WAN”

• WAN covers a large geographical area

• External/public infrastructure is used

• Non-dedicated software