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COMPUTER NETWORKS & THE INTERNET - Contenido educativo
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Today we are going to talk about something that is very important in our society
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because it has changed our life, because it improved the collaborative work and it led us to share our contents.
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So, it's a real revolution in the way we usually work using this kind of tools, IT tools.
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We are going to talk about network, computer network and obviously the internet.
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So the first thing that we must know is the definition of a computer network.
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A computer network is a set of computers and devices connected to each other for the purpose
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of sharing information and resources.
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that can be shared on the network not just only a software or files but it can also some hardware,
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hard disks, printers and so on. It can be shared the program information and data managed by
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different users also. In all networks or communication system you will find
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the same elements, the elements of communication that are transmitter, receiver, we also need a
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channel and obviously the measured that I want to transmit that must be encoded and decoded.
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So the code is so important. To do the communication with the computers we have already known some codes.
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If we take into consideration the size of the computer network, we can classify the networks into at least three different types.
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The lowest or the smallest is land. In a land or a local area network you just only cover a building,
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no more than a building. If you cover more or less a city you have a man network,
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the metropolitan area network and if it is bigger you have a one which is a large
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scale network a wide area networks so taking into consideration the size of
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the computer network we have these three types if you take if you take into
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consideration the ownership we can have public private and virtual private networks private
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networks is a you you you have a sex in a public way it's a global way one best example can be the
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internet it is private is just only for some users for example the different
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types of intranets you have a lot of types of intranets most commonly LANs
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generally is for LANs or for FTP services also and finally virtual private
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network is the interconnection of various providers network using the
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structure of global network well if you take into consideration how to manage
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the network we can have two types client server that is an old-fashioned model in
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in which you need at least one computer
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which is different from the other computers, the client.
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This computer control and manage the traffic
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of the network, and it's usually so called a server.
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So you need a server in order to manage the network.
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And the rest of the computers must connect it to it.
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But nowadays it's very very usual that we haven't any server, all the computers are servers, so we usually have peer-to-peer network in which there is no nodes, all nodes or workstations are simultaneously clients and servers, and it's a new model that is usually used nowadays.
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If you take into consideration the topology, we have three main types.
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The first one is bus.
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The networks share the same channel, called a bus, with a single cable, is no longer used.
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In topology, the information circulates in one direction and each computer analyzes whether
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it is the target for the information.
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In star topology, all computers are connected to a hub or a switch which transmits the information.
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The most common thing is that we have mixed topologies nowadays.
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Well, other important thing is if we have cable or not, or we have wireless, that's
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the reason why we can use different types of wire.
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The most common is UDP, unsheathed wisdom pair, it's a cable consisting of copper or
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aluminum wires interlaced in pairs to avoid interference.
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Depending on the number of wires we use and the length of each strand, we have different
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speeds of transmission, and it's called category cuts.
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So we have different cables with different capacity.
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Another type of cable can be STP that is similar to UTP but is more secure.
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Nowadays you usually use also optical fiber that consists of a group of very thin wires
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made of transparent material, generally glass or plastic, over with pulses or light
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repressing transmitting data and sent. The light source be laser or LED. It has very high
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brand width and its speed is bigger. For Wi-Fi technology,
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which is a computer network data we need a Wi-Fi routers 0.6 as a remote transmitters so we can
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use recession devices Wi-Fi cars and so on motherboards is a very is is the the technology
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that we usually use nowadays without any cable wireless if we want to create the LAN as over
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other apps with the computer you need some hardware and also some software the typical
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hardware is in this slide we have the network card or the network board a network card are
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devices that connect computers to the network and are usually integrated into the motherboards or
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mobile computers a other thing is the router this is a computer network interconnection device
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its main function is to send information and find the best route that connect to computers
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We also can have switches, hub, but it's not so much usual, these both are the most usual.
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Well, apart from the hardware, we also need some.
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The network protocol is the software required for two computers in a network to communicate with each other.
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Computers speak the same language to share information, and this language is usually
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so-called communication protocol.
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Although there are a lot of protocols, nowadays we usually use the TCPIP protocol.
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The TCP IP protocol controls the packets of different datagrams.
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The IP is responsible for addressing and the ports.
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Each node or element in a network must be identified by its IP address.
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The IP number consists in a set of four decimal figures of one byte separation by dots, which
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can have values from 0 to 255 and the IP address gives you information about the
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type of net and the type of the connection for example if you are in the
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same land all the figures in the IP address are the same if set the tool
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this to the last two the last two is your own your own others is what
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identified you in a land source for example apart from this it's important
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to know how to routine or the content of a gateway we usually do our networks in
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With the land networks, we create the manned networks and with the manned werewolves, we
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create one werewolf in this way.
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So to control the access to the nest level, we need what we usually call a gateway, mostly
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in the land level.
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The gateway is the IP address of the access to the internet in a LAN.
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So all the computers must connect it to this gateway if they want to connect to the internet.
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Finally, some services that are really interesting, for example, it is really complicated to memorize
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set of figure the IP address but you can transfer this IP address in something
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that uses and you understand better is what we usually so
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called DNS. So in DNS, for example, instead of 147.96.1.15, we can use www.ucmx. You know
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www means that you are on the internet worldwide web then is the mine and you
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can also have a subdomain and finally is connected with the country or the
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activity of the web pages well in any case in any case the combination of one
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P address and the port that let you to do the connection this combination is
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usually so called socket so in this table you can know the ports that do the
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connection and the protocol and the purpose of service that you can have if
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you use this combination for example you have this this protocol is very
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it's very familiar for you because it's the control is the protocol
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for website weights and this is for file transfer or all of these protocols are for incoming email
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so the socket is a the combination of the protocol and the port I think is all that
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you need to know connected with networks then maybe we I think I'm going to to do
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exercises and finally a test.
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- Idioma/s:
- Autor/es:
- Isabel Lafuente Reboredo
- Subido por:
- Isabel L.
- Licencia:
- Reconocimiento - No comercial
- Visualizaciones:
- 129
- Fecha:
- 13 de octubre de 2020 - 19:08
- Visibilidad:
- Público
- Centro:
- CP INF-PRI-SEC EL CANTIZAL
- Duración:
- 16′ 35″
- Relación de aspecto:
- 1.78:1
- Resolución:
- 1920x1080 píxeles
- Tamaño:
- 164.15 MBytes