Networks 6.1. Network Basics 1.1 Definition 1.2 Classification 1.3 Elements6.2 Internet. Home services6.3 Network protocol

InidicadoresDefinir el concepto de red informática y distinguir sus elementos básicos y los tipos de redesConocer los principales tipos de conexiones existente, así como el concepto de ancho de bandaComprender los conceptos de protocolo de comunicación, dirección de red y nombres de dominio

6.1.1 Definition

A computer network is a connection between several computers in order to be able to share resources, files, etc.

6.1.1 Definition

Thanks to networks we can use the same printers, projectors, scanners or even files that are connected to a different computer

6.1.2 Classification

We can identify each type of net according to its coverage and distance between users

6.1.2 Classification

LAN or Local Area Network, includes several computers connected by switch in the same building. You could find it in any office like the Administration office of your school.

6.1.2 Classification

MAN or Metropolitan Area Network is the connections of several LAN situated for example in different buildings from a same company.

For example an University and its faculties are connected forming a MAN

6.1.2 Classification

WAN or Wide Area Network is the connections computer around the world, that’s Internet.

When we visit a webpage like Tuenti, we are connecting our pc with the server of Tuenti

6.1.3 Elements

Server

Users

Connector/wireless

Switch

Let’s see the main elements in a network

Modem

6.1.3 Elements

Connectors: We need something to send the information, we can use cables, mobile phone or wireless waves.

Wireless: It reach only close users non more than 30m.

Wired: It need a physical connection but it gives high connection flow

6.1.3 Elements

We need and element to connect all pc together a switch or a router

6.1.3 Elements

Router: connects all computers together, both wireless or wired 4 pc

Switch: connects several, 12 or 24 computers together with wires

Router and switch

6.2 Internet. Home services

Internet provider and modem: we can be connected to a network, but we need a adaptor to get connected to the Internet provider. This transmitter is called modem. There are several types

6.2 Internet. Home services

All these elements are used to connect our pc with the Internet Servers

Mobile Modem: mobile phone companies can give us internet connections

Telephone wire Modem: We use the telephone wire to connect our modem

Cable Modem: We use the cable to connect our modem.

6.2 Internet. Home services

We can use the telephone wire and a modem to connect to Internet providers like jazztell, ya.com, telefónica, etc. We can't get big bandwidth.

Telephone wire Modem: We use the telephone wire to connect our modem

6.2 Internet. Home services

In big cities first and nowadays not so big, we can get connected to the optical fiber. This cable get us really a big bandwith. These internet providers are ONO, R, etc…

6.2 Internet. Home services

Nowdays we can connect our computers everywhere using mobile modems. These are more expensive and give low bandwidth. These internet providers are Movistar, Vodafone, Yoigo, Orange, etc

Mobile Modem: mobile phone companies can give us internet connections

6.2 Internet. Home services

What is bandwidth????It’s the available data communication resources expressed

in bits/second or multiples of it (kilobits/s, megabits/s etc.

Nowadays we get from 0,5Mb to 20 Mb

0,5 Mb 5 Mb20 Mb

6.2 Internet. Home services

There are several bandwidth meters online, where you can evaluate your internet connection.

6.2 Internet. Home services

If someone is downloading big files at high speed you will have less bandwidth, it’s like having a leak in a pipe

6.3 Network protocol

As do with mobile phones, computers need a number to identify each pc that is surfing on the net

80.53.127.12

126.54.12.13

This number is the IP. All computers working in a network get a local IP number by the switch and a another IP for Internet

6.3 Network protocol

When we say that we are connected to Internet, we are getting in contact with different computers named Server

IP: 209.85.143.99IP: 69.171.228.40

IP: 95.131.168.196

6.3 Network protocol

So, when we write www.tuenti.es the computer calls 95.131.168.19, and we enter in their computer

IP: 95.131.168.196

6.3 Network protocol

If we write 95.131.168.19, instead of www.tuenti.es we get there too¡¡¡¡

95.131.168.19

6.3 Network protocol

All computers have a IP in internet, but servers have a public IP so everyone can see what is inside

privet IP

privet IP

Public IP

Public IP

Router Public IP Router Public IP

6.3 Network protocol

Users have privet IP so anyone can get in us. Although our modem provides a temporal public IP

192.168.1.3192.168.1.1

192.168.1.1

192.168.1.2

192.168.1.2 192.168.1.3

6.3 Network protocol

Check this out¡¡¡ In both networks pc and routers have the same IP????

192.168.1.1

192.168.1.1

192.168.1.2

192.168.1.2 192.168.1.3

192.168.1.3

Each network is independent, but when we connect to Internet we get a public IP different than the rest

6.2 Internet. Home services

Some bandwidth meters online, gives us our external IP too

6.3 Network protocol

If you want to know your IP in your network, you have to go to run ipconfig on your terminal.

6.3 Network protocol

If you want run ipconfig, you have to go to Start, Run, type CMD, and then type ipconfig and press enter