Operating systems functions User Interface to handle interaction with user via windows, icons, menus and pointer (WIMP) File management to ensure data is stored properly and the location recorded CPU management or ‘multi-tasking’ to control the time each task is allowed to execute in the processor I/O management to monitoring input and output from devices such as a monitor, or printer or speaker

Communication methods

Common faults with software A system freeze where the whole system locks and no key or click can release it, which may be as the result of a virus or software bugs. The frozen ‘blue screen’ of a Windows-based system, which can be caused by issues with driver software. Program closes or crashes or ‘hangs’ due to coding ‘bugs’ by original programmer and their poor testing Update errors that can occur because an upgrade has not been applied or is incomplete and so the software malfunctions Software failing to load that could be due to software error or problems loading file from storage

Protocols used for checking faults Protocol for checking faults on a local area network: Simple Network Management Protocol (SNMP) Is used by IT technicians such as when monitoring devices on a network, such as printers, hubs and switches or even normal PCs

Protocol for handling problems delivering packets on the Internet: Internet Control Message Protocol (ICMP) Is used by routers and other network devices to generate error messages when problems delivering packets

Types of servers File server that stores large number of files and controls security, such as access rights to files for users on a network Print server that manages queue of documents for printing and shares load of print requests across available devices on a network Mail server that stores & forwards emails like an electronic post office where data traffic is controlled by protocols eg SMTP (send) & POP (receive) Web server that stores all files for a website, such as HTML code plus images & video, and sends all those files to user’s browser using the HTTP protocol

Virtualisation

For virtualisation with storage: ‘Virtual’ storage, which means combining multiple storage devices so they appear to work as a single data store That would help because it makes it easier for IT Support to back-up data from a single store, rather than data that’s spread across different devices

For virtualisation with servers: ‘Virtual’ servers, which means using spare capacity to make single servers operate like they’re multiple ‘virtual’ servers running more applications for more users That would help because IT support have less servers to maintain and upgrade, which saves time and costs on hardware

For virtualisation with clients: ‘Virtual’ desktop’, which means the user interface and applications on each client computer is controlled centrally by IT support That would help because the technicians can manage all updates automatically from their central servers, rather than doing updates manually on each client computer, which saves a lot of time (and therefore money)

Topologies

Topologies - Bus Is a simple set-up based on a main backbone cable that connects all devices. Advantages Bus is reliable – if one workstation or ‘client’ fails, rest of network still works Flexible expansion – it is easy to add extra workstations to the backbone cable Disadvantages Dependent on Backbone – if the main cable fails, then whole network fails Performance - As more workstations connected, more data collisions slows performance Security – Very weak as all clients receive all data

Topologies – Token Ring Uses a closed loop of cable where devices take turns to transmit data to reduce collisions. Advantages Cabling – Basic layout is simple so easier to install Transfer speed – Good because devices take turns to transmit to reduce ‘collisions’ Disadvantages Ring route – data must travel through all workstations to reach destination machine Broken links – If one client fails, then network affected

Topologies - Star Very popular set-up where devices have links to a central device, such as a switch. Advantages Reliable – if a cable or device fails, network is OK Expansion – Adding extra machines won’t disrupt others Data traffic – Can monitor network using central hardware, such as switches that are ‘smart’ and route data to correct devices Disadvantages Cost – Need to buy central hardware, such as switch Dependence - if central hardware fails, then network fails!

Networks

Networks - servers Peer-to-Peer Is a set-up that’s idea for smaller networks where basic aim is to share files between machines. Client-server Is a set-up for large networks that need a server to give centralised control

Discussion of Advantages & Disadvantages Cost: With a peer to peer network, one advantage would be that company would not need to purchase a central server, whereas a client- server network would be more expensive to set-up because a company would need to buy server and also possibly a switch to handle data traffic. Security: Peer to peer networks are good for simple sharing of files but security is weak, which makes it a disadvantage for a company, where staff need to share private data about customers. But on the other hand, a client-server network has better security because it gives central controlled from the server for logons and file access rights, which is an advantage for a company where staff need to share private customer data.

Justification of best option:

Choosing networks Ethernet (Protocol) Is the most popular physical method or ‘layer’ for local area networks (LANs). When a machine on the network wants to send data to another, it senses the carrier (which is the main wire connecting all the devices). If it is free, i.e. no one is sending anything, it sends the data packet on the network, and all other devices check the packet to see whether they are the recipient. The recipient consumes the packet. If there is already a packet on the highway, the device that wants to send holds back for some thousandths of a second to try again until it can send. Token ring Is the most popular method for LANs that use a ring topology.

Discussion of Advantages & Disadvantages If a business decided to use a ring network, then Token ring has the advantage that it prevents data collisions by using a shared token for devices to take turns to transmit data. So whichever device has the token can send data and then the token passes to the next device along the ring. The obvious disadvantage is that this approach only works with ring networks. So if a business decided to use another topology such as a star network, then Ethernet has the advantage that it has a clever protocol for managing data collisions. After detecting a collision, Ethernet makes each device delay by a random amount of time before re-transmitting the packet.

Justification of best option

WAN/LAN An office in a business will have its own Local Area Network or LAN. But the business may also want to link those offices to create a Wide Area Network or WAN. This will enable staff across the company to work together more efficiently, such as by sharing data more easily between offices Each LAN also needs to connect using the largest WAN of them all – the Internet.

ADSL This is the connection method used by most homes and many businesses, which uses traditional copper phone lines. Advantages ADSL gives a broadband connection with good data transfer speeds (or ‘high bandwidth’). ADSL is easy to install with familiar hardware devices such as a router (with built-in modem) plus micro-filters that split voice and data to send via the phone line. Disadvantages ADSL uses the shared public telephone system so is weak on security unless the business also uses a Virtual Private Network or VPN, which would use encryption to scramble data being sent over the WAN.

Leased Line Is a popular choice for businesses that want a dedicated connection between their sites, such as between the different offices across the country. Advantages Having a dedicated line means you do not share it with any other users (which is also known as ‘uncontended’) That means you are guaranteed a very high bandwidth, which will give fast data transfer for a business It also means your data is more secure, which will keep data private for the business Leased lines also normally use fibre optic cable, which also gives much faster data transfer than copper cable Disadvantages Leased lines are more expensive to buy as a package from a telecoms company or ISP internet service provider). A leased line will also take more time to set-up and install because it involves fibre links

Justification of best option

Business systems A Management Information System or MIS is the type of software that’s designed to gather data for analysis about different areas of an organisation’s performance For example, MIS could collect data from databases about customers and their purchase history and then analyse potential improvements to sales performance, such as generating a report on the products that are most or least popular But a business would also face costs associated with an MIS, such as buying and installing the software and then training its staff to know how to use the application properly

Customer relations management (CRM) Customer relations management (CRM) is the process that tracks how a business interacts with current and potential customers or clients For example, it allows a business to centrally store customer information such as records of emails/letters & meetings plus their sales histories A business may also face potentially difficult issues when setting- up CRM, such as linking it with existing systems for storing emails and documents

Standard operating procedures (SOPs) Standard operating procedures (SOPs) are detailed step-by-step guides to how tasks should be carried out within an organisation to make sure they’re carried out accurately and in the same way each time. For example, a business could use SOPs in the form of step-by- step guides to using MIS or CRM so that staff know how to collect data use the system so that the resulting information remains accurate and useful. But organisations must take care that SOP guides are not too strict that they stop staff being creative, or force them to spend more time on admin rather than the job itself.