Realizado por: Ángel Alonso Ana Montero

- A workstation is connected to a network by: a) A network interface card b) A hub c) A switch c) A router - Which of these types of network cable is not affected by interference from other cables?: a) UTP b) Co-axial c) Fibre-optic d) Thin Ethernet - Which of these devices allows many computers to connect to a servers network interface card?: a) Router b) Switch c) Modem d) Bridge - A computer network that is confined to a one site is called a: a) MAN b) LAN c) WAN d) Peer-to-peer - A company provides its users with a network that can be accessed from its offices worldwide. This network is: a) A LAN b) A MAN c) A WAN d) An intranet

- Explain the difference between a LAN and a WAN Describe what differences there are likely to be in the way computers are connected in a LAN and in a WAN. LAN : WAN : A university has many buildings spread out over a campus. State what type of network would link its computers together State the type of cabling that the university would be most likely to use to make connections between different buildings and explain the reasons for this choice Una LAN es una red que cubre un área relativamente pequeña y una WAN es una red que cubre un área mucho más grande. Es capaz de cubrir distancias desde unos 100 hasta unos 1000 km. Su extensión esta limitada físicamente a un edificio o a un entorno de hasta 100 metros. Sería una MAN ya que es una red que conecta otras redes locales y no se extiende más allá de los límites de la ciudad. El tipo de cable más común en las universidades sería UTP o par trenzado ya que disminuye la interferencia debido a el área de bucle entre los cables.

- On a particular network, one computer is used to store the data shared by all the users. State what this computer is called Se llama servidor.

- Chris works from home and does a lot of work on his computer, programming and writing documentation. He decides that it would be a good idea if he were to install his own network. a) Explain three advantages that Chris would gain from having a network b) Explain three disadvantages of setting up such a network c) Apart from the usual computers and peripherals, describe three extra items of hardware that Chris might have to obtain in order to set up his network. State the purpose of each component Permiten compartir información de la base de datos, los periféricos caros como las impresoras láser pueden compartirse, las redes hacen la comunicación más fácil. Las redes son vulnerables a problemas de seguridad, si un servidor causa problemas la la empresa puede pararse, las redes pueden ser caras de establecer. Es necesario los cables (UTP, co-axial o fibra óptica) para unir las redes, la tarjeta de red que nos permite la comunicación entre diferentes aparatos conectados entre si y también permite compartir recursos entre dos o más equipos y los interruptores que son cables de los ordenadores para unirse a una tarjeta de interfaz de red sobre un servidor.

d) Chris wants to connect his network to the Internet. He considers using a modem for this purpose. Explain the purpose of a modem e) He decides to use a broadband connection. Explain why a broadband connection is a good choice Los módems convierten las señales digitales (0s -1s) del ordenador a señales analógicas (el voltaje variable) señales usadas por una red telefónica. La red de banda ancha ofrece la velocidad más alta de transmisión de datos, el sistema de banda ancha esta siempre activo, hay menos demora cuando se utiliza la banda ancha, ofrece acceso a los servicios de Internet de más alta calidad.

- A small company designs the layouts for books. It employs three designers who use desktop publishing software to arrange the text and ilustrations that they receive by from the authors. A secretary uses office software for administrative purposes. The company is planning to install a network with six workstations and two servers. a) Explain, with examples, why this company might require two servers rather than just one b) State two ways in which the network will allow the company to improve the security of its data files c) Explain why the company might now need to appoint an extra member of staff Porque con dos servidores todas las actividades no se concentran en un solo servidor y así la red irá más rápido. Una manera de proteger los datos en la red es con el uso de contraseñas y otra manera es haciendo copias de seguridad por si algún día se pierden los datos de la empresa. Pues podría necesitar a alguien que supervisara el rendimiento de los ordenadores y arreglara los daños de los ordenadores si los tuvieran.

d) Describe what the role of this person would be Controlar el mantenimiento de la red, en caso de problemas que lo arregle y controlar los virus que puedan llegar a entrar.

- When a user on a network prints a file, it goes into a print queue just before printing. Where is this queue held?: a) On the servers hard disk b) In the servers RAM c) On the clients hard disk d) In the clients RAM - On a network, a payroll clerk needs only to be able to view personnel records. A suitable level of access to these files would be: a) Read/write b) Execute c) Read-only d) Delete - A workstation on a network is also called: a) A server b) A hub c) A terminal d) A client machine - A small network that does not have a server is called: a) A peer-to-peer network b) A ring network c) A star network d) A bus network - On type of network has all the devices connected to one common cable with a terminator at each end. This is called: a) A ring network b) A bus network c) A star network d) A peer-to-peer network

- The diagram below shows the layout of one particular type of network. a) A state the name of this type of layout b) Part D is where all the shared files are stored. Name all the parts indicated by letters: A B C D c) Describe one advantage of installing this particular type of network d) Describe two weaknesses of this particular type of network Una red bus (de autobús) TerminadorOrdenador cliente Cables de conexiónServidor Es fácil de instalar Si hay un problema con un ordenador la red entera deja de funcionar y si hay muchos ordenadores conectados la velocidad de la red baja mucho.

- A small firm of insurance brokers is considering installing a network. One of the options they consider is a peer-to peer network. a) Explain what a peer-to-peer network is b) Explain why this type of network may be suitable in this situation c) A client-server system is chosen instead. Network software is installed on all the computers. The server has multitasking software installed. Explain what is meant by multitasking Funcionan sin clientes ni servidores fijos, sino una serie de nodos que se comportan como como iguales entre sí, es decir, actúan simultáneamente como clientes y servidores respecto a los demás nodos de la red. Porque gracias a ellas pueden manejar grandes bases de datos y para ese tipo de empresa les viene bien. Pues que son capaces de dar mas de servicio a un usuario al mismo tiempo.

Explain why multitasking software is necessary on a server machine State two advantages of using a client-server network layout d) The server software has many security features. State three of these features Porque es en el ordenador servidor donde se concentran todas las actividades de los otros ordenadores que están conectados a la red. Centralización del control (los accesos, recursos y la integridad de los datos son por el servidor de forma que un programa cliente defectuoso o no autorizado no pueda dañar el sistema y fácil mantenimiento (al estar distribuidas las funciones y responsabilidades entre varios ordenadores independientes, es posible reemplazar, reparar, actualizar… Algunos archivos y directorios son reservados para ciertos usuarios y bloqueados para otros los usuarios son colocados en grupos de modo que el director de red pueda organizar sus derechos más fácilmente y el historial de redes guardado por si hay problemas que puedan ser investigados.

- What software is use to display web pages?: a) Operating system b) client c) Browser d) HTML - An advantage of using the telephone instead of is: a) With telephone messages, the person is reached immediately b) s can often be misunderstood c) Telephone calls are cheaper than s d) Telephone conversations are completely private -An advantage of is : a) It can be accessed from any connected computer in the world b) It is totally secure c) You only receive the communications that you want d) It cost nothing to send - Why is it a good idea not to open s from unknown sources?: a) Opening them will lead to more junk b) Opening them will waste space on your hard disk c) Opening them way reveal passwords to others d) They many carry a virus - Video conferencing is often of poor quality when internet connectivity used. The most likely reason for this is : a) The internet cannot send moving pictures b) Many users do not have broadband connections c) The operating system of many PCs is incompatible with video conferencing d) Web cameras do not have enough pixel density

- State four reasons why is often prefered over other methods of communication Describe two drawbacks of Describe three reasons why business may want to communicate with its customers via web pages Explain why video conferencing is best achieved with a broadband connection Porque es rápido, barato, lo puedes enviar en cualquier momento y puedes adjuntar en el los archivos que quieras en él y enviarlo. No es seguro y los mensajes pueden ser malinterpretados. Es versátil, puede ser usado como medio publicitario y se puede tomar la orden de ellas. Se necesita banda ancha porque se trasmiten mucho megabytes(al menos 10) de datos por segundo.

- A business traveller is staying in a hotel in England. He has to keep in touch with his office from time to time. His son is back-packing in Australia. Many methods of communication are available. For each of the following situations, sate a suitable method of communication and give a reason for your choice. - Explain two reasons why a home can benefit from connection to satellite communication systems Situation Suitable method of communication Reason Sending a message to his son Discussing a customer´s account with the sales manager Demonstrating a product to a number of customers in different locations Sending a spreadsheet file to head office Video conferencia Barato y entrega rápida Imágenes de las personas se ven pero cada uno en un lugar diferente Satélite Se envían simultáneamente mucho datos FaxSe proporciona la impresión Porque pueden enviar muchos datos simultáneamente y porque gracias ellas se ven canales de televisión

- Broadband network connections means: a) More bits of data are transmitted per second b) Thicker cables are used c) More cables are used d) Fibre-optic cables are used - The reason why image files are often compressed on internet sites is: a) The image quality is improved b) They transmit faster c) Fewer pixels are used in the display d) Browsers can only display compressed images. - Which of these could improve the response time a network?: a) Change to a bus network topology b) Increase client disk space c) Add an extra hub d) Give the server more RAM - A person often wants to download music from the internet but finds it too slow. The best way to reduce download times would be to: a) Change to a different ISP b) Install more RAM c) Install a broadband connection d) Increase hard disk space - It is a good idea to limit the amount of graphics on a web page. Which of these facts is relevant? a) Most surfers have small amounts of RAM b) Some surfers use ISDN c) Some surfers have broadband connections d) Limiting graphics reduces download times

- Data is often sent over networks in a compressed form. Explain what this means and the advantage of doing it The following are commonly used compression standards. For each one, state what sort of file is being compressed. - Explain why it is often a good idea to limit the amount of graphics used on a web page Comprimir es reducir el volumen de información. La compresión pretende transportar la misma información, pero empleando una menor cantidad de espacio StandardTaype of file JPEG GIF MPEG Imágenes Componentes páginas web Películas Porque así las descargas son mucho más rápidas

- A modem is advertised as being 56 kbps. How long is the shortest time that it would take to download a file of 1 MB? Show your working In practice, the 1 MB file may take longer than this to download. Explain one reason why this might be the case · 100 = 5600 bps Porque si hay mucha gente utilizando ese servidor se producen retrasos.

- A small college uses a 3-station client-server network for its administration. The computers are connected by a bus cable. Recently, with increasing student numbers, the office staff have noticed that the network performance has slowed down. - Explain how each of the following factors may influence network performance and how changes can be made to improve the networks speed. a) Network topology b) The network cards c) The specification of the server Al ser una red bus todos los datos van en una misma dirección y se producen colisiones. Al solo haber un servidor y por lo tanto una tarjeta de red todos los ordenadores salen a Internet por la misma dirección y esto hace que vaya lento. Si tiene poca memoria RAM y se incrementa el numero de alumnos esto hace que vaya más lento

- Explain why network performance can be improved by storing commonly used applications on local hard drives rather than on the server An ISP needs to have servers with a high specification. Explain what this means and why it is important in this case Porque se reduciría trafico de la red y el rendimiento sería más rápido. Porque los ISP son el acceso a Internet y si no tiene los servidores las especificaciones correctas no podrán acceder a Internet.