Computer networks, protocols and connection

what are advantages of networking

users can share files, peripherals, access file from any computer on network, servers control security, software updates and backup of data, communications wit others

describe lans

small geographical area, hardware owned by organization, wired by utp cable

describe wans

large geographical area, infrastructure owned and managed by telecommunication company, connected with telephone lines

computers in lan connected with

switch

computers in lan connected by

router

disadvantages of networking

increased data security risks, malware and virus spread easily ,if server fails, computer connected to it may not work, runs slowly due to amount of data travelling

define bandwidth (factors affecting network)

how much data can be sent and received in a given time

what is bandwidth measured in

bit rate

define number of users (factors affectng network)

too many users cause bandwidth to slow down if insufficient bandwidth for data

define transmission media (factors affectig netwoek)

wired connections have higher bandwidth than wireless connection, fibre optic cables have higher bandwidth than copper cables

define error rate (factors affecting network)

less reliable connection increases number of eroors occouring when data sent, data has to be resent until arrives correctly

define latency (factors affecting network

delay from transmitting data to recieving it caused by bittlenecks in network

Describe client server model

server controls access and security to a shared file storage, manages access to the internet, manages printing jobs, provides email addresses, runs backup of data, Client makes request to server for connections and data

advantages of client server model

easy to manage security files, take backups of all shared data,install software update to all cmputers

dosadvantges of client server model

expensive setup, server is single point of failure, requires IT specialist to mantain, user will lose access if server fails

describe peer to peer model

peers serve their own files to each other, responsible for own security, responsible for its own backup, usually has own backup, equal to all peers

advantages of peer model

easy to manatin, no specialist staff needed, not dependent on one computer,cheap, no expensive hardware needed

disadvantage of peer model

less secure, users manage own backups

What is NIC (network interface controller)

connects device to wired or wireless networking connection using protocols to ensure successful transmission

What is wireless access point

allow wireless enabled device to access network, these are popular as avoid need to install cables

Bandwidth on a wireless connection

lower than wired network

switch uses nic address to

route traffic

explain router

needed to connect lan to wan and uses ip address to route traffic to other routers

Connections between switch and desktop computers

made with utp copper cable

copper cable is

cheap and flexible and easy to install

longer distance cables and wans

connected with fibre optic cables

fibre optic has

higher bandwidth than copper suffering less interference

the internet is

global collection of interconnected networks

What does DNS do

converts easy to remember web address to ip adress for routers

What is hosting

storing websites on servers dedicated for dns resolver server

hosted solutions provide

24/7 acess, multiple users, great security

what is a network topology

a given arrangment of all elements you need for networking

describe star topology

has central switch all devices connect to, switch is intelligent making sure data only goes where needed, if single cable breaks only that computer affected

disadvanteges of star topology

switch is point of failure

describe full mesh topology

every device connected, if you break a connection data can still be sent via another route, disadvantage high cost of cabling

Partial mesh topology

multiple routes between device but not all of them connected, lowering amount of needed hardware

define protocol

set of rules allowing two devices to communicate

TCP

provides error free transmission between two routers

IP

routes packets across a wan

HTTP

client server method of requesting and delevring html webpages

HTTPS

encryption deliviring webpages

FTP

sending files between computers on a wan

POP

retrives email from mail server, removes it and sends to your device

SMTP

sends email to email secer

IMAP

retrieve email from mail server and manange remote mail boxes

advantages of layers

reduce complexity of problems, produvts from dofffrent vendors work together

Layer 1

Mac frames (sent over fibre optic)

Layer 2

IP routing

Layer 3

TCP error handling

Layer 4

browser using https