computing - network and topologies

Network topology

A given arrangement of all the elements that you need for networking

Star Network

Most popular, all connected to central switch

Star network adv

Intelligent switch makes sure traffic only goes where intended, if single cable breaks, only that computer is affected

Star network disadv

Switch is big point of failure

Full mesh network

Every device is connected to all other devices

Full mesh network adv

If break in any connection, traffic can reroute to other routes

Full mesh network disadv

Lots more cabling and switch hardware required, more cost

Partial network

Multiple routes exist between different devices

Partial network adv

slightly less cabling, compromise lowering amount of hardware

Advantages of using networks

users can share files, prints and connections to other networks, they can access files from any computer, server controls security and backup, easier communication

Disadvantages of using networks

Increased security links, malware and viruses spread easily, if server fails connected computers may not work, computers may run slower if many users

Two types of server models

client and peer to peer

Client server adv

easier to manage security files, easier to take backups of all shared  data, easier to install software updates to all computers

Client server disadv

expensive, requires specialists to maintain, server is single point of failure, users will lose access if server fails

Client server

controls access and security to one shared file store, manages access to internet and print jobs, provides email services, runs backup of data and clients make requests for data and connections

Peer to peer adv

easy to maintain, no dependency on single computer, cheaper, no expensive hardware

Peer to peer disadv

less secure, users manage own backups, difficult to maintain well ordered file store

Peer to peer

computer on network equal to others, serve own files to eachother,  each peer responsible for own security and backup, is possible to share but both things have to be on

bandwidth

The amount of data that can be sent and received successfully in a given time, measured in bits per second, often called bit rate 

number of users

Too many users or devices on the same network can cause the network to slow down if there is insufficient bandwidth for the data 

transmission media affecting

Wired connections have a higher bandwidth than wireless connections. Fibre optical cables have a higher bandwidth than copper cables 

error rate

Less reliable connections = more errors = more resending

latency

delay from transmitting data to receive it, caused by bottlenecks in the infrastructure of the network 

network interface card/controller (NIC)

network connected computers need it, lets devices connect to network, mostly integrated

wireless access point

allow wirelessness, convenient, less bandwidth, bad security, not as strong

Switch

Sends data between computers on LAN, forwards traffic to right place, intelligent

Router

Cant connect wan without, sends data between networks, uses IP, address, creates wan from number to lan

Transmission media

Copper and fibre optic cables

Cooper cables

Connection ensures Maximum security, bandwidth and reliability, twisted pair reduce interface, grade affects

Fibre optic cables

Uses light, longer distances, used by backbone of internet

Internet

known wan, collection of interconnected networks

Web servers

Commonly host websites and take client requests, 24/7 access, good security

Cloud

Servers store data and programs, auto backup, anytime any device, large storage