GCSE OCR COMPUTER SCIENCE – NETWORK EXAM QUESTIONS AND ANSWERS

What is a network? A network is a set of connected computers and other devices in order to share resources. This includes files, application software and hardware. What are the two types of network? LAN and WAN What is a LAN? Local Area Network - covers a small geographical area What is a WAN? Wide Area Network - covers a large geographical area What is network infrastructure? Network infrastructure is the hardware and software resources of an entire network that enable network connectivity, communication, operations and management. Who owns the infrastructure of a LAN? The infrastructure is owned by the individual. Who owns infrastructure of a WAN? The infrastructure is owned by the telecommunications company or a third party. What are advantages of a LAN? - Share hardware for example a printer - Files and resources can be shared - Can work collaboratively on files - Can access work on any computer within the LAN - Central deployment of software to all computers - Central deployment of updates to all computers - Instant messaging can be used across the LAN What is the role of a server in a network? The function of a computer server is to store, retrieve, update, install and send computer files and data to other computers on a network What are three different types of servers - Web server - File server - Email server What is a web server? A web server is server software, or hardware dedicated to running this software, that can satisfy client requests on the World Wide Web. What is a file server? File servers offer users a central storage place for files on internal data media, which is accessible to all authorised clients. What is an email server? A e-mail server, is an application or computer in a network whose sole purpose is to act as a virtual post office. The server stores incoming mail for distribution to local users and sends out outgoing messages What are client - servers? Client - server has two different devices, these are a clients and a server/file server the role of the server is to control access and manage the network. Clients are computers on which the user works on. What are peer to peer networks? Peer - to - peer has only one device and these are computers. Each computer is equal and can communicate with each other directly without going through a server. What are advantages and disadvantages of client - server networks? Advantages: - Easier to maintain security of files - Easier to take backups of all shared data - Easier to install software and updates to all computers Disadvantages: - Can be expensive to setup and maintain - Requires IT specialist to maintain - The server is a single point of failure. Users will lose access if the server fails What are advantages and disadvantages of peer to peer network? Advantages: - Very easy to maintain. Specialist staff are not required. - No dependency on a single computer - Cheaper to setup. No expensive hardware required Disadvantages: - The network is less secure - Users will need to manage their own backups - Can be difficult to maintain a well ordered file store What is a network topology? A network topology is the layout of the network. What are three types of network topology's? - Full mesh - Star - Partial mesh Explain the network of full mesh: In a full mesh network, all devices are connected to each other and are involved in the transmission of a message. No central router is required, as there are multiple paths between the devices. The devices can directly talk to each other. Explain the network of star: The star network topology has a central device directly connected to all other devices. Explain the network of partial mesh: In a partial mesh network, most devices are connected to each other and are involved in the transmission of a message. No central router is required, as there are multiple paths between the devices. The devices can directly talk to each other if connected to each other. What are advantages star network? Advantages: - Data is only directed to the intended computer directly - Network traffic is kept to a minimum - If one link if one link fails all other computers will continue to operate - It is easy to add new devices without disrupting the network - Data collisions are less frequent What are disadvantages star network? - If the central point fails, then so will the entire network - Requires a lot of cable as each computer is connected individually to the central device What are advantages of mesh network? - Data can be transmitted from different devices simultaneously - If one component fails, there is always an alternative route for data - Can handle high volumes of data traffic - Adding more devices will not slow down the data transmission What are disadvantages of mesh network? - Overall cost is high. More cable is required unless a wireless network is used - Difficult to manage and requires expert supervision What is an NIC and what is it used for? A Network interface card (NIC) is used to connect to a network. The NIC formats the data sent to and received by the computer. These are often built on the chips on the computers motherboard. What is a switch? A switch is a network device which creates a separate collision domain on each port, while remaining within a single broadcast domain. What is the roll of the router in your home? A wireless access point (WAP) is required to connect wireless to a network/internet. They convert data received into wireless signals. Routers connect different networks together, the example of your home network to the internet. They read the address and forward these from your computer to the correct network. Routers are used to transfer data between a home network and the internet. The internet is a network of computer networks. What hardware is required to connect a standalone computer to a network? - Wireless access point (WAP) - Routers - Switches - Network interface cards (NIC) - Cables (Transition media) What is a wireless access point? A wireless access point (WAP) is required to connect wireless to a network/internet. They convert data received into wireless signals. What is a router? Routers connect different networks together, the example of your home network to the internet. They read the address and forward these from your computer to the correct network. Routers are used to transfer data between a home network and the internet. What is transmission media? Transmission media is the cables and wireless connection. These are the communication channels that carries the information from the sender to the receiver. What are different types of transmission media? - Wireless - Cables What are the two main types of transmission media Broadband and fibre broadband What are differences between broadband and fibre broadband? - Fibre broadband has faster speed - Fibre broadband has shorter contract - Fibre broadband has more expensive monthly cost - Fibre broadband has more expensive setup cost Why are there these differences between broadband and fibre broadband? The type of transmission media being used What are two types of cable transmission media? - Copper cables - Fibre optic cables How do copper cables send data? Copper cable uses electrical signals to pass data between networks through copper. How do fibre optic cables send data? Fibre optic cabling is made from glass that becomes very flexible when it is thin. Light travels quickly through the light reflecting internal wall of the cable. Why are fibre optics better than copper cables They can send data over further distances and faster because light travels faster and longer than electricity What is an advantage of copper cables? They are cheaper than fibre optic cables How do wireless transmission media work? Wireless requires there to be WAP which is usually built into the router and the other device must be able to send and receive wireless transmission. Wireless is slower the cables as wireless uses radio waves and would depend on interference.