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Standalone device - a self-contained device or a system that can perform its functions without the assistance of any other device or connection. These devices do not need to communicate with any other device. Networks are a collection of computers and devices connected by communication channels tha...

Standalone device - a self-contained device or a system that can perform its functions without the assistance of any other device or connection. These devices do not need to communicate with any other device. Networks are a collection of computers and devices connected by communication channels that facilitate user communication and allow users to share resources. Networks can be internal to an organisation or used by users to connect the world to the Internet. The main reason for a network's existence is to share information, such as spreadsheet files, database records, email feeds, and anything that helps someone get their job done. Sharing resources such as servers, printers, and software makes networks valuable. For successful communications to occur a network needs: A sending device, such as a notebook computer, initiates an instruction to transmit data, instructions or information. A communications device, such as a wireless adaptor inside a notebook computer to forward packets of data, instructions or information from a sending device via signals carried by a communications channel. A communications channel or transmission media, such as a cable or radio waves, through which the digital signals travel. A communications device such as a wireless router, receives the signals from the communications channel and forwards the packets to the receiving device. A receiving device such as a printer that accepts the data, instruction or information Devices such as personal computers, tablets and mobile phones are types of sending devices that can also be receiving devices. These types of devices usually have a built-in communications device. Data, instructions, and information travel along a communications channel in the form of a digital signal. Digital signal - consists of individual electrical pulses that represent the bits grouped into bytes. Advantages of networks: Sharing data and information - when devices are connected, they are then able to share information and data as a file on one device can be accessed by another device. Communication - Users can connect through emails, video conferencing, and online chatting through the connection of network devices. Hardware and software sharing - When devices are connected and can communicate, they can also share other digital system resources. Types of networks Networks can be categorised into two groups which are either the Local Area Network (LAN) or a Wide Area Network. The type of network refers to the area over which the network provides connectivity. Local Area Network This type of network can connect computers and devices in a limited geographical area, such as a home, school, or office building. Each device on the network is referred to as a node. These nodes in LAN are connected through cables. Newer networks now use wireless transmission media. A wireless local area network also known as a WLAN uses no physical wires or cables but rather uses wireless media such as radio waves. However, if a computer or a device attempt to use a WLAN it must have a wireless capability whether is it built-in or ad hoc using a USB wireless receiver. A WLAN will communicate with a wired LAN for access to its resources such as software, hardware, and the internet. A network architecture contains logical designs of the components of the network and includes the number and types of servers, workstations, and network resources. This includes the communications devices and the types of physical and wireless transmission media used to connect components. Home networks: Multiple devices can connect with a home network. The advantages of a home network include the following: Desktop computers, notebooks, tablets and smartphones can all communicate with each other. All computers can be connected to the internet at the same time. All computers can share peripherals such as a scanner, printer, or a network-attached storage device. Each networked computer can play multiplayer games with players on other computers in the house. Smart TVs can connect to the internet. Wide Area Network (WAN) This type of network is situated in more than one geographical location. This often consists of two Local Area Networks in different locations that can communicate with each other using an internet connection. Example: Two offices, with its own Local Area Network, can communicate with each other using an internet connection. Difference between Local Area Network and Wide Area Network A Wide Area Network uses Third-party transmission media are transmission media that belong to another organisation. This will often be a telecommunication organisation such as Telstra or Optus. Once an organisation uses third-party transmission, it starts to lose some control over the network and the potential for data threats increases. This is what a home network looks like: Network Architecture This refers to the layout of the network, including the hardware, software, protocols and transmission media used. Each type of network can be categorised further by its architecture. There are two common types of network architecture a peer-to-peer network and a client- server network. Peer-to-peer network This is a simple, inexpensive network that is typically used to connect organisations or groups of people with fewer than 10 computers. Each computer on a peer-to-peer network can share hardware (such as a printer) data or information that is located on any other computer in the network. Each computer can store files on its storage device or another computer. Within each computer, the network contains both a client operating system like the “Home” versions of Windows) with basic networking capabilities and application software. All computers on the network share any peripheral device attached to any computer. For example: one computer may have a laser printer and a scanner, whereas another may have an ink-jet printer. They may also share a network-attached storage device (NAS) with a movie and music repository. Peer-to-peer networks are popular in homes where a login server is neither necessary nor practical. Client-server network This server is sometimes called a host computer and controls the access to the hardware and software on the network and provides a centralised storage area for programs, data and information. Besides storage capacity, a server allows for file sharing, website hosting, email management and access to shared printers. The other computers of the network would be called clients and rely on the server for these resources. For example: A server in a school’s administration might store a database of student details. Every client on the network can access this database on the server. The costs related to a server-based network are significantly higher than those for a peer-to- peer network. This equipment is not only necessary to construct u networks more expensive but a client-server network also requires ongoing technical support to maintain the sophisticated hardware and software. However, there is a positive side which is that there are clear economies of scale as the cost of adding clients that share the server’s resources becomes relatively less. There is one major difference between the server computer and the client computer is that the server has more storage space and power. There are some servers called dedicated servers. Dedicated servers perform specific tasks. For example, a file server stores and manages files. Each user on the Local Area Network can share files or program steps on a file server. A print server manages printers and print jobs. Print hobs received from Print users on the LAN are queued on the print server in the order of their Server arrival and fed to the various network printers on one document at a time. Database A database server stores and provides access to a database. server Network A network server manages network traffic. server Several servers are often configured in a type of rack which makes it easier to manage the cables and the power supplies. The server rack is often located in a specialised room where the temperature is kept cool to offset the amount of heat generated by the power-hungry servers. In the past, network administrators were used to dedicate each server to a particular task. The use of one application per serve made it easy to track administrators down any problems that arose. However, this does not take advantage of the processing power of modem servers. A large storage room is also required as the number of servers is increased. In the present many servers in networks are virtual rather than physical. Specifically designed software is used to convert one physical server into many virtual servers, each responsible for a particular purpose. A client-server LAN can connect a smaller number of computers, it is typically most efficient for it to connect 10 or more computers. Most client-server LANs have a network administrator due to their large size. administrator Network Administrator — is the operations person in charge of the network. Many schools have a client-server network installed. This allows staff and students to store data on shared drives. Wireless Personal Area Networks (WPANs) Personal Area Network (PAN) - is a computer network for connecting an individual’s devices within a limited range. A Wireless Personal Area Network (WPAN) - is a type of personal network that uses wireless transmission media to transfer data between a user’s devices. It allows a person to connect their devices and access the Internet on a local network using wireless communication techniques. A WPAN is also known as a short-range wireless network. Some common types of devices that are found within a WPAN are desktops, laptops, smart televisions, wearable technology, smartphones and speakers. A WPAN may use these wireless communication standards: 802.11(x) Bluetooth infra-red (IR) satellite microwave Networking hardware and software Hardware and software are required for data to communicate between devices on a network. Hardware is the physical components of a network while software contains the instructions to the hardware, enabling it to complete specific tasks. Network Hardware Each network hardware component provides a different function to manage, control, and secure data and information to be communicated on a network. Hardware used to manage, control, and secure data includes: Network interface card (or wireless adaptor) server wireless access point router switch modem Network interface card (or wireless adaptor) Each device needs to have a network interface card (or wireless adaptor) installed to allow access to the network or information system. A network interface card slots into the motherboard of a device and then provides ports to allow the device to connect to a network. A wireless adaptor is connected to the motherboard and allows the device to send and receive wireless signals. Many devices come with both a wired network interface card and a wireless adaptor installed. This allows the device to communicate with other devices. Server Server — a device that is used to provide services to other devices connected to a network. For example; Many networks have a file service. All of the files of the organisation may be stored on one or multiple servers and users operating other devices also known as clients can then access the data from these servers. Most of the time data and information related to an online or browser-based information system will be stored on a web server. When a user wants to access the information system they will be directed to the web server, where they will be able to access the data and the information required. Servers can be set up on a network to control and manage specific tasks on the network. The below are all types of servers: FILE SERVER — this is used to store files in a main location and manage the files so that authorised network users can access them from the main location. This type of server does not require to perform any tasks such as processing tasks and does not need to run on any application or software. Its main purpose is to enable users to store and retrieve data. WEB SERVER — this type of server is used to store the files related to a website, a group of websites or an online browser-based information system. When a user wants to go onto a web page, the request is sent to the web server, which then sends the web page and the related files to the user using Hypertext Transfer Protocol or HTTP. The Universal Resource Locator or the URL of each web page is converted o an IP address that directs the request to the specific web server. PROXY SERVER — this type of server manages all network requests for resources from the internet. Any request by a network user for resources from the internet will first be sent to the proxy server. The proxy server then sends the request for resources to the internet. When the proxy server receives the resources, it directs them to the correct user. DATABASE SERVER — this type of server stores database application and the data used by the application. The user is able to access the data stores on a database server through “front end” software, installed on their device, that collects the required data. In addition to storing data, the database server can perform analysis on the data. PRINT SERVER — this type of server receives requests for printing from network users and sends these requests to the printers installed on the network. It allows requests to be centrally stored to be managed and controlled. EMAIL SEVER — This type of server sends and receives all emails for users on a network. Each time a network user sends an email, it will be sent to the email server, which will then forward it on to the recipient. When an email is sent to a user it will be first sent to the email server which will then deliver it to the user. A copy of all emails sent and received is normally stored on the email server. Wireless Access Point A wireless Access point also known as a WAP is a communications device used on wireless Local Area Networks. It acts like a central transmitter and a receiver of wireless radio signals. A wireless access point is normally connected to a wired network backbone for a faster transmission of data back to the network server. Wireless access points are used in business networks where larger buildings and spaces need wireless coverage. Home networks are generally small enough that a wireless router can provide sufficient coverage without the need for an access point. If and area is too large to be covered by a single wireless access point, then multiple access points can be used. There can be momentary loss of connectivity when a user movie from the located of once access point to another access point. Overlapping access points provide a seamless area for users to move around in and uses a feature called roaming. When a user moves from one area to another the wireless networking hardware automatically jumps to the access point that gives the strongest signal. Router A router is a device that connects different networks, such as (LANs) or a LAN and the internet (WAN). A router is able to link all these networks regardless the type of hardware or communication protocols within the network. For example, when data is sent over the internet or a big company network, routers receive data packets. They check the packet to find the source and destination IP addresses and send the data to its correct location. Unlike switches, which use MAC addresses to decide where to send data, routers use IP addresses. Companies, such as Vodafone, offer 4G modem sticks that can connect laptops or mobile devices through a phone network so they can connect to the internet. These sticks are portable and easy to use for mobile internet access. Broadband routers A broadband router is typically used for home networks and is able to join multiple networks. These routers are designed specifically to join the home (LAN) to the internet (WAN) to share internet connections. A wireless broadband router combines the functions of a basic router such as connecting the LAN to the internet, a switch which allows devices such as a computer to be connected by a cable, a firewall which is a security measure, and a wireless access point which allows wireless connectivity. The type of broadband router used to act as a bridge between a LAN and the internet depends on the type of connection provided by the internet service provider (ISP). A cable connection uses the high bandwidth which is available through the same broadband connection that provides information to a television via a provider such as Foxtel. An asymmetric digital subscriber line, also known as ADSL, is a connection which provides internet access using copper wiring in telephone lines. The cost of an ADSL broadband router is in the range of $150 to $200. A cable broadband router is usually sourced from an ISP since it has to be registered on the ISP's network before it will work. Switch A switch is a device used to connect different devices within a local network (LAN). It keeps track of the addresses of all devices connected to it. When data which is in packets is sent through the network, the switch checks where the packet is supposed to be and sends it only to the cable that leads to the correct device. This ensures that the data reaches its destination quickly without interfering with other devices. When a switch sends data directly between two devices, it works as if those devices are directly linked. On a 100 Mbps switch, all devices can send and receive data at full speed without interruptions. To improve security in wireless networks, it's important to encrypt data and use strong passwords for file sharing, routers, and access points. This makes it harder for unauthorized users to Modem A Moden is a device that is used to connect LAN to the internet by converting digital signals (binary) into analogy (audio) signals and then back again so data can be transmitted over a telephone line. In the past most organisations had a connection to the internet though using a telephone line for data communication. The advantage of this was that most homes and organisations would already have a telephone connection and so there would be no need o install a nerd connection at each location. The National Broadband Network (NBN) has introduced a fibre-optic network across much of Australia. Many homes are connected via 'fibre to the curb' (FTS), meaning that fibre-optic cables run to the street, and from there, copper cables (called unshielded twisted pair) connect the fibre network to the house. In these setups, a modem (also known as an NBN connection box) is still needed to manage and control the internet data. However, unlike older modems, it doesn't need to convert signals from analogy to digital in this case. Merging Technology Many of the devices discussed in the preceding pages have now been merged into a single device as technology has improved. These devices include: Modem/router router/wireless access point router/switch modem/wireless access point/router Network Software Software is used to control, manage, and secure data in a network. Network operating system Each network needs a network operating system. A network operating system also known as a network OS or NOS is the system software that organises, controls, and managed the activities on a Local Area Network. A NOS controls the attached computer systems, any factors, and the communication between the, the tasks that NOS performs include: administration - adding, deleting and organising users and performing maintenance tasks, such as backup file management - locating and transferring files device management - coordinating print jobs and reports sent to specific printer on the network, ensuring resources are used correctly and efficiently. security - monitoring and, when necessary restricting access to network resources. Wired, Wireless and Mobile communication technology Wired cabling, wireless transmission and the use of exiting mobile or cellular networks are communication methods which can be used to transmit data and information over a network. The method used to transmit data depends on the needs of the user of the network even though each method has strengths and weaknesses in terms of cost, data storage options, data transfer rates, reliability, and security. Wired communication technology A wired network is a type pf mapwork in which devices are connected through the use of a physical cable. Some advantaged of wired networks compared to wireless networks include: faster data transfer speeds — While wireless speeds are improving, wired networks still generally offer faster and more consistent data transfer, especially on average. better security — Wired networks are harder for hackers to access because it’s difficult to intercept data. There's also less risk of data loss due to signal interference. more reliable connection — Wired networks have more stable data transfer rates and are less prone to interference, unlike wireless networks, where signal strength and speed can fluctuate. Some disadvantages of wired networks compared to wireless networks include: lack of mobility — Devices connected to wired networks have to stay near fixed connection points, making it harder for users to move around while staying connected. installation — Setting up a wired network is more expensive and time-consuming than installing a wireless network, as it involves buying and laying cables. maintenance — Wired networks can require regular maintenance, like fixing cables or adding new data points, which can also be costly and time-consuming. Twisted-pair cable Commonly in transmission media for network cabling and telephone systems a twisted-pair cable is used. This cable contains one or more twisted-pair wired bundles together. Each twisted-pair wire is made up of two sperate insulated copper wired that are twisted together and this is because it reduces noise. Any noise in an electrical disturbance can degrade communications. Fibre-optic cable A fibre-optic cable is a wired transmission media that contains shard of glass, which reflect pulses of light generated by small lasers or light-emitting diodes or also known as LED. The core of these cables is made of dozens to hundreds of thin strands of glass or plastic that use light to transmit signals. Each of these strands is called optical fibre which is as thin as human hair. Inside this cable an insulating glass cladding and a protective coating surround each optical fibre. Fibre-optic cables offer several advantages over twisted-pair cables: They can carry many more signals. They provide faster data transmission. They are less affected by interference from devices like copy machines. They offer better security since they are less prone to interference. They are smaller, thinner, and lighter. Fibre-optic cables work by reflecting light internally, preventing it from escaping. This makes them immune to electrical noise, allowing data to travel over much longer distances compared to twisted-pair cables. However, fibre-optic cables are more expensive and harder to install or modify. Despite this, many telecom companies and businesses are switching to fibre-optic cables for their high- traffic or main network connections. National Broadband Network The National Broadband is designed to provide the infrastructure to deliver affordable and reliable high-speed internet and telephone access to all Australians. The National Broadband Network (NBN) aims to provide all Australians with affordable, reliable, high-speed internet and telephone access. Due to Australia's large size, different technologies are used to deliver the NBN. Initially, the plan was to provide speeds of 100 Mbps, with fibre-optic cables connecting most homes directly to the internet. However, the plan has changed. Now, fibre-optic cables are run to a node in the street (called a 'street cabinet'). From there, hybrid cables or existing copper telephone lines are used to connect homes and businesses. Other technologies used for the NBN include coaxial cables, fixed wireless, and Skymaster satellite connections. Households where fibre-optic cables cannot be used will connect to the NBN through fixed wireless and satellite technologies and this is up to 10 per cent of homes that need wireless or satellite connections. Wireless communication technology A wireless network is a computer network that connects devices without using physical cables, relying on wireless data transfer, usually via radio communication. Wireless networks can include: Wireless Local Area Networks (WLANs) Mobile networks Satellite networks Microwave networks Wireless transmission is useful when installing cables is inconvenient or impossible. The latest wireless standard, 802.11ax, provides speeds comparable to wired networks. Common wireless transmission methods include broadcast radio, cellular radio, microwaves, communications satellites, and infrared. An 802.11ac wireless router typically operates on the 5 GHz frequency but can also function on the 2.4 GHz network simultaneously. Some manufacturers advertise these routers with a combined speed of 1.75 Gbps, which comes from adding 1.3 Gbps from the 5 GHz band and 450 Mbps from the 2.4 GHz band. Wi-Fi Communications For Wi-Fi communication, a transmitter sends radio signals, and a receiver accepts them. The receiver has an antenna that needs to be within the signal range. Some networks use a transceiver, which can both send and receive signals from wireless devices. Although Wi-Fi communication is generally slower and more susceptible to interference compared to wired connections, it offers flexibility and portability. Wireless networks typically operate on two frequency ranges: 2.4 GHz and 5 GHz. The 5 GHz network can carry more data but has a shorter range, meaning it doesn’t penetrate obstacles like walls as well as the 2.4 GHz network. However, the 2.4 GHz band can be affected by interference from household devices like cordless phones. The 5 GHz band has less competition from these devices. Many modern devices now support dual-band capabilities to take advantage of both frequency ranges. Bluetooth Bluetooth technology uses short-range radio waves to transmit data between Bluetooth- enabled devices. Each device has a small chip that allows it to communicate with others within a specific range—typically around *10 meters, which can be extended to *100 meters with additional equipment. Common Bluetooth-enabled devices include desktop computers, laptops, handheld devices, mobile phones, fax machines, and printers. Bluetooth is popular for hands-free calling on mobile phones and streaming music to speakers or car audio systems. Most new cars come equipped with built-in Bluetooth, allowing users to sync their mobile phones easily. Both Bluetooth and Wi-Fi use radio signals for communication. Near-field communication (NFC) is a technology that allows for contactless communication between devices, such as smartphones and tablets. Users can simply wave their NFC-enabled smartphone over an NFC-compatible receiver to share information without physically touching the devices or needing a formal connection. This technology is commonly used for making payments in stores or for paying parking meters, which can even send messages to the smartphone about the remaining time. An NFC-enabled device can work with a small, unpowered chip called a tag. This tag draws power from the NFC device that reads it through a process called electromagnetic induction. Smartphones can be paired with NFC tags, which can be programmed with apps to perform automated tasks. For instance, if you tap your smartphone on an NFC tag embedded in a movie poster, it can transfer information from the poster to your phone. This might include details like showtimes, actor biographies, and reviews. Similarly, tapping on a restaurant's menu tag could load the menu onto your phone, along with nutritional information and cooking notes. NFC tags are small and inexpensive to produce, making them ideal for various applications, particularly in mobile payments and innovative marketing strategies. As awareness of NFC technology grows, more creative uses are expected to emerge. Examples of NFC technology in action include PayWave transactions and Victoria's Myki transportation system. With these systems, users can simply wave their NFC-enabled card near a card reader to transfer data quickly and easily, completing transactions in almost no time. Microwaves Microwaves are a type of radio wave that enables high-speed signal transmission. Microwave transmission involves sending signals between microwave stations. This method can be a practical alternative to cabling, especially when an organization has facilities on opposite sides of a road. Digging tunnels for cables can be expensive and time-consuming, so microwave technology offers a more efficient solution. A microwave station typically consists of an Earth-based reflective dish that contains antennas and other necessary equipment for communication. The dish collects signals and directs them to a central collector. Microwave transmission is line-of-sight, meaning that the microwaves must travel in a straight line without any obstructions, such as buildings or trees, between the antennas. To minimize potential obstructions, microwave stations are often placed on top of buildings, towers, or mountains. Electromagnetic radiation, including light and radio waves, travels nearly as fast in the air as it does in a vacuum (approximately *300,000 km per second). This means that microwave communication is significantly faster than fibre-optic transmissions, which send laser light pulses through glass strands. The glass can slow down the light by *50 to 40 per cent. Microwave transmission is ideal for situations where installing physical transmission media is difficult or impractical, especially in large sites where line-of-sight transmission is available. Communications Satellites A communications satellite is a space station that receives microwave signals from an Earth- based station, amplifies (strengthens) these signals, and broadcasts them back over a wide area to multiple Earth-based stations. These stations are often microwave stations, but other devices like handheld computers and GPS receivers can also serve as Earth-based stations. Uplink: This refers to the transmission of signals from an Earth-based station to a satellite. Downlink: This is the transmission of signals from a satellite back to an Earth-based station. Mobile Communication Technology A mobile network, also known as a cellular network, enables communication through mobile devices using a series of mobile phone towers, or base stations, that send and receive signals. The coverage area of these towers often overlaps, allowing users to stay connected as they move within a region. The range of each mobile phone tower can vary based on its location and the number of nearby towers. In large cities, towers are often close together, allowing for minimal gaps in coverage. In more isolated areas, a tower might cover a range of 2 to 3 kilometres, but typically these towers still overlap to maintain connectivity. When a user is in range, their mobile device connects to the nearest base station. Each base station connects to a digital exchange that facilitates communication. Mobile networks support voice calls, data transmission, text messages, and multimedia messaging. However, there may be costs associated with data transmission, particularly when users exceed their plan limits. This can lead to additional charges, especially when roaming or using data-heavy applications. Internet of things The Internet of Things is a network formed by “smart devices” such as mobile phones, wearable devices, headphones, heating systems, refrigerators and other devices that have an on-and-off switch to the Internet and or other Internet of Thing’s devices. There are many ways in which devices can communicate data with each other. Device-to-device This is a communication that happens when two devices communicate directly with one another without the help of any other device. These devices communicate with each other using the same communication protocol such as Bluetooth. Device-to-device is more commonly used in systems that require the transfer of small data packets between devices at a low data transfer rate. This could be a virtual assistant, smart speakers or light dimmers that send small amounts of information to each other. Device-to-gateway This type of communication involves an IoT device that connects to a “gateway” that forwards the signals to another device in the local area. The gateway can be a router or a smartphone with the right software installed. The router or the smartphone normally had internet connectivity to allow data to be sent and received over the internet. The software installed on a smartphone typically acts as a gateway could be a software application. This application would have security measures to help in the protection of data and information communicated and assist in managing the transfer of data from the device to other devices. Device-to-cloud This type of communication involves an Internet of Things device that connects directly to the Internet or the cloud. Devices that transmit data directly to the cloud require a component that can transmit data to the internet directly. This could be through a wired, wireless, or cellular connection. Cloud connectivity is usually used with devices that do not require any human interaction or the ability to communicate with other devices locally. For example: A smart electricity meter that is used to upload to the cloud the amount of electricity consumed in a house each month. Technical underpinnings of networks Intranets An intranet is a private network that only has access to uses within an organisation. For example: The MGC network is only accessible to those who go to the school or work there and contains resources to help and guide both students and staff. An organisation's internal intranet is not like the Internet and contains information and services such as calendars, policies, procedure manuals, and technical support files that are unavailable to the public. An intranet also allows access to documents needed within the organisation. Many intranets also have search engines, user profiles, blogs, notifications, and event planning functionality. An intranet is a website-based information system that is made up of several HTML pages that are stored on a web server and this is similar to many websites. Users of the intranet access the information using a web browser such as Chrome, Safari, or Firefox. An intranet will often include a connection to the internet, allowing employees access to information from the web. Intranet pages will often include links to internet sites with information relevant to the organisation. An intranet offers the following efficiencies: - Facilitates group collaboration among employees. - Speeds up data access and loading of graphics and images, as information doesn't pass through a router. - Reduces paper waste by digitizing documents and processes. - Improves ease of use through point-and-click technology for accessing hyperlinked documents. Effectiveness benefits include: - Provides restricted access to company information for security. - Enables easy and fast updates to company documents compared to hard copies. - Supports communication across different network platforms (Windows, Mac, UNIX) using universal HTML code. - Allows authorized users to access intranet data from anywhere via the internet. - Supports communication through audio and video files, in addition to text and images. Internet The Internet is a worldwide network in which billions of devices are connected for communication and data exchange. The internet uses common communication protocols to link the network devices with each other. Two major concepts that allow devices to communicate on the internet are IP addresses and the protocol TCP/IP. IP addresses Every device that is connected to the Internet must have a unique address. This address is called the IP address. The IP addressing standard is four numbers, each between 0 and 255 separated by full stops. IP stands for Internet Protocol. IP stands for Internet Protocol, a set of rules that allow devices to communicate over the Internet. An IP address is like a street address, helping to direct data to the correct destination online, similar to how a letter is delivered to a house. A public IP address is globally unique and assigned by an Internet Service Provider (ISP) either dynamically or statically. There are two types of IP addresses: public and private. A private IP address, typically in the range 192.168.1.1 to 192.168.1.254, is assigned by the user and is not globally unique, as it’s used within a private network. TCP/IP The Transmission Control Protocol/Internet Protocol (TCP/IP) is a set of rules that allow communication between two networked devices. TPCA is a combination of two protocols (TCP and IP). It ensures that the messages travelling over the internet reach the destination IP address. TCP/IP can also be used on Local Area Networks (LANs). Transmission Control Protocol When data is sent over the internet, TCP: - converts the data into packets - sends each packet towards the destination - arranges the packets in the correct order when they arrive - reassembles the packets back into the correct format at the destination. TCP is also responsible for resending any packets lost during the communication process. Internet Protocol IP is responsible for addresses and the routing of the packets to the correct destination. It uses packet switching to do this. Packet switching When data is sent across the internet, TCP breaks it down into small packets. When IP directs each packet across the internet, each packet may travel by a different route to the destination. As each packet is sent, IP identifies the most efficient route to the destination: at that time. As the next packet is sent, the most efficient route. Accessing websites A website is made up of several web pages that be accessed over the internet by entering the site’s domain name or internet address. All the resources of the website such as pages or files are stored on a web server. Behind each domain name is an IP address that directs the request to the location of the web browser where the resources are stored. Virtual private network (VPN) A VPN stands for a virtual private network and allows users to use public networks such as the Internet to send and receive data and information as if they were using a private network like an intranet. VPNs were developed to allow users to access an organisation's application and resources securely from remote locations. Security is maintained by adding protection strategies such as requiring users to authenticate their identity with passwords or other techniques when they attempt to log in to the VPN. A VPN can be used to avoid geo-restrictions and censorship to protect users' anonymity and conceal their location while they are surfing the internet. For Example: There are many shows on Netflix and many of them are international shows that cannot be viewed in other countries. To view this material the user would need to use a VPN so that they can view this media in another organisation. Network Diagrams A layout diagram is a common tool used to visually represent a network's appearance. It helps create a network diagram that shows the topology of the network. A network diagram displays the nodes (such as desktops, laptops, and mobile devices), network hardware (servers, routers, switches, modems), and communication methods (wired, wireless, mobile). It can also include security controls like authentication techniques, firewalls, and system protection protocols. The diagram focuses on network components and work areas (e.g., dispatch, and marketing departments) rather than the physical layout of the buildings, which could make it harder to read. Security Threats A threat to a network is anything that has the potential to cause harm to data and information stored and communicated between information systems. A threat may or may not occur but it has the potential to result in the loss, theft or damage of data and information. Several measures can be used to minimise the chances of a security threat. Credential management Credential management involves verifying a user's identity to ensure they are who they claim to be, which is crucial for managing data and networks. Techniques like usernames, passwords, biometric security, and swipe cards help prevent unauthorized access. Additional verification methods, such as asking for personal details (date of birth, driver’s license number, etc.), are also used, especially in online systems. Two-factor authentication, which requires two forms of identification, is increasingly common. Credential management must be well-maintained, especially with staff turnover or role changes requiring adjustments to access rights. Users may forget their credentials, leading to resets, which should include strategies to ensure the requesting person is the legitimate user. Malicious software Malware is short for malicious software and is software that is designed to damage and disrupt or even gain unauthorised access to an information system. This term is used to group a range of software threats to data and information. Viruses A virus is a software application that is written to cause some type of negative effect on a device or a network. When a virus is executed, it normally duplicates itself in a range of locations on a device. A virus may be designed to damage, steal, modify or corrupt data. Worms A worm is software that when it is installed self-replicates. A worm continues to replicate itself over and over again which causes the system of a device or a network to degrade and slow down over time as the software starts to drain all of the system resources. Spyware Spyware is software that collects data about a user’s activity and sends that data to another location without the user knowing. Spyware can also include functions that allow network or security settings on a user’s device to be changed. Like other malware, spyware can be downloaded inside a Trojan horse a type of virus or after clicking on a link in an email. Denial-of-service attacks A denial-of-service (DoS) attack occurs when hackers attempt to prevent legitimate users from accessing a service by overwhelming a network or server with a large number of authentication requests. These requests often come from fake or non-existent addresses. When the network or server tries to authenticate and respond to these requests, it cannot find the return addresses, causing the server to wait before closing the connection. Once the server closes the connection, the attacker sends more invalid requests, keeping the server busy and preventing legitimate users from accessing the service. Hackers can also send fake data packets to all computers on a network or initiate SYN (synchronization) flood, where connection requests are sent to all open ports without completing the handshake process, leaving no ports open for legitimate users. A distributed denial-of-service (DDoS) attack is similar to a DoS attack but originates from multiple sources, significantly increasing traffic on the network. This makes the attack more effective and harder to shut down or trace back to its source. Username and password A combination of a username and password is one of the most widely used security controls. Each user is assigned a unique username, and typically, they create their password. Together, these are known as the login. Some systems require passwords that meet specific criteria. Common requirements include: - At least eight characters - At least one upper-case letter - At least one lower-case letter - At least one symbol - No spaces - Cannot be "password" - Cannot be the same as the username Short or single-word passwords are a security risk, as they are vulnerable to brute-force attacks. Obvious passwords, such as "password", or reusing the same password across multiple systems, increase this vulnerability. A brute force attack involves repeatedly attempting to guess a password using different variations of usernames and passwords. Attackers often target known usernames, like an email addresses. Bots are commonly used in these attacks, starting with simple password attempts like "a", "b", and "c", and continuing through more complex combinations like "aa", "ab", and so on. This method systematically tries every possible combination until the correct one is found. Access rights Access rights are a form of permission that has been granted to a user, or to an application to read write and delete files on a network. By failing to apply access rights, or by not managing access rights correctly, an organisation will fail to restrict the number of users that have rights to access data and information. This increases the chance of both user error and deliberation tampering with the data and information. Out of date Software Out-of-date software can cause several issues, as updates and upgrades are crucial for maintaining security and functionality. A software update, often called a patch, is a small file that fixes bugs, improves functionality, and addresses minor issues in existing software, such as security threats. Operating system updates and smartphone apps rely on these regular updates. A software upgrade, however, is a new version of the software that includes significant changes, such as improvements to security, functionality, and the user interface. For example, upgrading from Windows 8.1 to Windows 10 involves major improvements. Version numbers help differentiate updates and upgrades. They typically follow the format XYZ: - X: Major changes (e.g., version 2.0) - Y: Minor functionality changes (e.g., version 2.1) - Z: Bug fixes (e.g., version 2.1.1) Failing to update or upgrade software can lead to: - Vulnerability to new security threats - Missing out on new features - Poor battery performance or slower processing - Lower productivity - Reduced functionality due to bugs or errors Data and network protection strategies Using a variety of security measures is crucial to prevent unauthorized access to networks and data. Encryption Encryption is a key security control used to protect data during transmission and while stored. It involves encoding data so that only authorized recipients with the correct decryption key can access and understand it. Unauthorized users may gain access to encrypted data, but without the proper key, they cannot decipher it. For example, a credit card number used for online purchases is sensitive data that benefits significantly from encryption, ensuring that it remains secure during transmission and storage. Private and Public Keys To encrypt and decrypt data, a *key* is essential. A key, represented as a series of bits (0s and 1s), applies an algorithm to scramble (encrypt) and unscramble (decrypt) the data, effectively "locking" and "unlocking" it. Encryption software generates these keys. Examples of Keys: * - 4356 0241 - 0009 18DF - CUBED - EB2D FEDS - FD37 8989 - FC20 Common key sizes include *128, 192, and 256 bits*; larger keys provide stronger encryption. Types of Encryptions 1. *Symmetric Encryption* - *Definition*: Uses the same private key for both encryption and decryption. - *Key Characteristics*: The private key is only known to the user and installed on their device. The sender encrypts the data packet with this key, and the receiver uses the same key to decrypt it. - *Also Known As*: Private key or secret key. 2. *Asymmetric Encryption* - *Definition*: Involves two keys: a public key and a private key. - *Key Characteristics*: - The *public key* is shared with others and used to encrypt data packets sent to the user.  - The *private key* is kept secret and used to decrypt the data on the receiving device. - *Relationship*: The algorithms for the two keys are related, allowing data encrypted with the public key to be decrypted only by the corresponding private key. This dual-key system enhances security by ensuring that only the holder of the private key can access the encrypted information, even if the public key is widely distributed. Authentication Techniques Authentication is the process of verifying that a user of an information system is who they claim to be. Beyond usernames and passwords, there are several other techniques used for authentication: Biometrics *Definition*: Biometric authentication leverages an individual's unique biological characteristics to confirm their identity. *Types of Biometric Authentication*: - *Face Recognition* - *Fingerprint Recognition* - *Iris Recognition* - *Signature Recognition* - *Voice Recognition* *Process*: 1. Users initially submit their biological data, which is stored in a database. 2. When attempting to access a secure area or device, users provide their biological data again. 3. The input data is compared to the stored data. If there is a match, authentication is successful. *Advantages*: - Offers greater security compared to traditional usernames and passwords. *Limitations*: - Not 100% reliable; errors may occur, leading to legitimate users being denied access or unauthorized users gaining access. Digital Signatures *Definition*: A digital signature is an authentication technique used to verify the authenticity of electronic documents (such as emails, data files, or web pages). *Functionality*: - Confirms the identity of the sender. - Ensures that the sender has ownership of the document. - Verifies that the document has not been altered during transmission. *Process*: 1. A hashing algorithm generates a value from the data contained in the data packet. 2. The data packet is encrypted using the sender's private key. 3. The encrypted data is transmitted. 4. Upon receipt, the data is decrypted using the sender's public key. 5. A hashing algorithm is used again to convert the value back to its original form. *Verification*: - The combination of the hash value and encryption creates a unique format (the digital signature), enabling the recipient to verify the sender's identity and check for any alterations to the document during transit. By utilizing these authentication techniques, organizations can enhance their security measures, ensuring that only authorized users gain access to sensitive information. Preventative practices to reduce risks Preventative practices are intended to reduce data loss or theft due to security risks. Some practices may be software-based, process-based, or hardware-based which attempt to reduce the chance of different types of risks. Presentative practices aim to reduce the risk of data loss or theft but they cannot absolutely guarantee security. Software maintenance "Software maintenance involves updating software applications after they have been installed to fix faults, improve performance, or add new features. This process includes making changes to the programming code used to create the application. There are four types of software maintenance: 1. Adaptive Maintenance: Adjusting the software to changes in the operating environment. 2. Perfective Maintenance: Enhancing the functionality of the application. 3. Corrective Maintenance: Fixing bugs or errors in the application. 4. Preventative Maintenance: Improving the reliability of the application to reduce the need for future maintenance. Regular software updates and upgrades are examples of software maintenance. These updates are usually available for download from the software developer. Maintaining software helps address new security threats and improves the reliability of the software, reducing the chance of data loss and enhancing functionality. This allows users to be more productive when using the application." Operating system updates "Operating system updates are a type of software update released by organizations like Apple, Google, and Microsoft. These updates aim to improve the usability, functionality, and security of the operating system. When a new version of an operating system is released, users provide feedback on areas that need improvement. Cybercriminals and hackers also find vulnerabilities, so developers constantly update the code to address these issues. Operating system updates can include updates to associated applications installed on the device. These updates aim to improve: 1. Protection against spyware, viruses, and other malware: Enhancing security measures to protect the system from malicious software. 2. Protection against cyberattacks: Strengthening defences against unauthorized access and attacks. 3. Overall performance of the device: Improving the efficiency and functionality of the operating system, making the device run more smoothly. Regular updates help keep the operating system secure and efficient, reducing the risk of data loss and improving user experience." Virus definitions A virus is a type of software designed to cause harm to a device or network by damaging, stealing, modifying, or corrupting data. When a virus runs, it duplicates itself across multiple locations on the device. Antivirus software, part of system protection tools, scans a device or network to find viruses. To do this, the antivirus software uses virus definitions, which are collections of binary code that identify specific viruses. The definition for each known virus is stored in a database linked to the antivirus software. During a scan, the software compares files against the virus definitions. If a virus is found, the software either deletes it or quarantines it. However, if the antivirus software doesn't have a definition for a virus, it won’t be able to detect that virus. Since new viruses are created daily, antivirus software must be constantly updated to stay effective. This often involves downloading new virus definitions, which usually happens automatically, often every day. Firmware Firmware is software programmed onto hardware devices like TVs, DVD players, hard drives, mice, and keyboards, providing instructions for communication within a system. It is semipermanent, meaning it remains unchanged unless updated, and cannot be uninstalled. Firmware is vulnerable to security threats, so regular updates from the manufacturer are essential for protection and optimal performance. Disaster recovery plans A disaster recovery plan is a set of procedures for an organization to follow in the event of a disaster, aimed at restoring normal operations and minimizing data loss. The plan typically includes step-by- step instructions and various sub-plans: 1. *Emergency Sub-Plan*: Provides detailed instructions for emergencies, including evacuation procedures and contact information for emergency services. For example: - Operate the nearest fire alarm. - Leave the building by the nearest exit. - Report to the designated assembly point. 2. *Backup Sub-Plan*: Outlines how to restore backups, including: - Locations of backups. - Backup types and restoration times. - Step-by-step restoration instructions. - Contact details for key personnel regarding backups. 3. *Recovery Sub-Plan*: Contains procedures for recovery after a disaster, such as: - Restoring power to the building. - Replacing damaged equipment. - Restarting hardware and reinstalling software. - Restoring backups. 4. *Test Sub-Plan*: Details the steps to test the disaster recovery plan, often through drills that simulate a disaster. Testing helps identify necessary changes or improvements to the plan. Overall, a disaster recovery plan is essential for ensuring that an organization can quickly resume operations and safeguard its data in the face of a disaster. Staff protocols Staff procedures are a set of steps that employees must follow when handling data and information within an organization. These procedures help ensure proper data management and security and typically cover: - Leaving devices unattended - Password requirements - File naming conventions - Acceptable use of the system - Email protocols - Internet usage and downloading guidelines Training staff to adhere to these procedures minimizes the risk of data loss or security threats. Common signs of intrusion Many unauthorised users are able to gain access to devices, information systems and networks which causes threats to arise. These unauthorised users are known as hackers and have many reasons to gain access without authorisation. These reasons are simply for enjoyment, for a challenge, curiosity, or to steal, data and cause damage. Some sings of unauthorised intrusions to device or a network includes: - Increased use of system resources - New software installed - Changes passwords - Sending spam email - Unknown applications requesting access - System protection software uninstalled - A device completing task by itself - Changes to a web browser home page. There could be many reasons why these behaviours might occur with unauthorised intrusion being one of them. If any signs are present then a range of tests should be applied to attempt to identify the causes of the issue. Increased use of system resources When an unauthorized user gains access to a device or network, they must first establish a connection, which increases the usage of the system's resources. Once connected, the unauthorized user can perform tasks that further consume system resources. This activity can negatively impact data transfer rates, processing speeds, memory usage, and graphics performance. New software installed The installation of new applications on a device or network without the user's knowledge is a strong sign of unauthorized intrusion. Such software often includes malware components, such as viruses, Trojans, spyware, adware, or keylogging software. Changed passwords A common indicator of unauthorized intrusion is the alteration of passwords. Intruders often change passwords to maintain control over a digital system, giving them more time to carry out their activities. To counter this threat, many organizations have implemented two-factor authentication, making it more difficult for unauthorized users to modify accounts. Sending of spam email After an unauthorized intrusion, hackers often gain access to an email system and start sending spam emails to all contacts in the user's address book. These emails appear to come from the authorized user and typically contain malicious content, such as phishing attempts or adware promoting services or products. Recipients may not be vigilant since they believe the emails are from a trusted source, which can harm the hacked user's reputation among friends and colleagues. Unknown Applications Requesting Access A firewall's role is to scan incoming data packets to ensure they have been requested. Following an unauthorized intrusion, the firewall may detect unrequested packets from unknown applications. The intruder may have installed software that requests data from external sources. If these applications are unfamiliar, the firewall will alert the user to this suspicious activity. System Protection Software Uninstalled If security software is found to be disabled without the user's knowledge, it may indicate an unauthorized intrusion. This can include antivirus software or specific security functions. An intruder may disable these protections to avoid detection. Without functioning security software, there may be delays in identifying the intrusion, allowing the hacker to continue malicious activities undetected. Device Completing Tasks by Itself If a device begins to perform tasks autonomously, it may indicate the presence of remote access software. This type of software allows a user to control a device from a remote location via an internet or network connection, without needing physical access. Signs of unauthorized control include the mouse cursor moving on its own, applications opening and closing, or documents and emails being typed without any user interaction. Changes to Web Browser Home Page Unexpected changes to a web browser's default home page can signal an unauthorized intrusion, known as home page hijacking. Hackers use this tactic for various reasons, such as: - Increasing traffic to a specific website. - Redirecting users to sites that contain malware or other security threats. - Collecting and transmitting personal data from users through the altered home page. - Displaying unwanted advertisements or adware pop-ups. - Prompting users to click on links claiming to fix the hijacked home page, which often leads to fake websites filled with viruses. Systems Used to Detect Intrusions To minimize the risk to data and information from intrusions, organizations use *intrusion detection systems (IDS)* and *intrusion prevention systems (IPS)*. Intrusion Detection Systems (IDS) An IDS monitors network traffic to detect potential intrusions and can be either hardware- based or software-based. There are two main types: - *Host Intrusion Detection Systems (HIDS)*: Installed on individual devices, HIDS monitors and analyses all data packets sent to or from the device. It alerts users if suspicious activity is detected by comparing current system files with previous ones and identifying any changes. - *Network Intrusion Detection Systems (NIDS)*: Installed at key points in a network, NIDS monitors network traffic, analyses data packets, and checks them against a library of known intrusion attacks. While both HIDS and NIDS serve to identify threats, an IDS primarily focuses on data packets traveling within the network, whereas a firewall primarily examines packets passing through the organization's firewall connection. Intrusion Prevention Systems (IPS) An IPS is considered an extension of an IDS. While an IDS identifies potential intrusions and alerts network staff, an IPS actively attempts to block or stop threats without human intervention. It can: - Delete suspicious data packets. - Reset network connections. - Block data packets from specific IP addresses. An IPS can be configured to follow predefined rules to automatically respond to certain types of identified activities. Ethical Hacking A *hacker* is a skilled computer expert who uses their abilities to gain unauthorized access to data and information on devices or networks. Hackers can be categorized as: - *Black Hat Hackers*: Individuals who exploit systems to steal data for sale or ransom. - *Grey Hat Hackers*: Those who hack for the challenge or prestige, without malicious intent. *Ethical hacking* involves a *white hat hacker* who has authorization to test a device or network. The goal is to identify weaknesses in the current security strategy, enabling organizations to improve their security measures. Organizations often seek individuals with limited inside knowledge of their networks to uncover vulnerabilities, operating under the belief that if a white hat hacker can gain access, so can a black hat hacker. Identifying and addressing these vulnerabilities is crucial for enhancing security. Common techniques in ethical hacking include: - *Penetration Testing*: Attempting to access a network with permission, such as testing network ports. - *Phishing*: Sending deceptive emails to members of the organization to test their susceptibility. Ethical hackers must respect the privacy of the organizations and individuals involved and report all identified vulnerabilities to the network owner. Using Networks in a Global Environment The use of networks has become widespread as the technology it requires has become more widely available, and the use of the internet and social media has become a seamless part of our lives. There are many clear benefits to using a network, from sharing hardware and software to accessing the internet. However, there are also risks associated with using networks, particularly in a global environment. This section looks at the benefits to individuals and organizations of using a network and the risks that may be encountered. #### Benefits Establishing a network has several advantages over running standalone computers and resources, including access to peripherals (e.g., printers), lower set-up costs (terminals are cheaper than standalone computers), and faster communications. Further advantages of using a network are discussed below. 1. *Sharing Hardware*: Each networked computer can access and use hardware on the network. For example, suppose several personal computers on a network each require the use of a laser printer. If the personal computers and a laser printer are connected to a network, the personal computer users can access the laser printer when needed. Businesses and home users network their hardware mainly because it may be too costly to provide each user with the same piece of hardware, such as a printer. 2. *Sharing Data and Information*: In a networked environment, any authorized computer user can access data and information stored on other computers in the network. For example, a large company might have a database of customer information that any authorized person, including a mobile user using a smartphone to connect to the network, can access. The capability to provide access to and store data on shared storage devices is an important feature of many networks. Project teams can share data, even if they are geographically remote, by using an organization’s virtual private network (VPN), which uses the internet for global connections. Networks support collaborative work practices through services such as cloud computing, email, and file transfer. 3. *Sharing Software*: Users connected to a network can access software (programs) on the network. To support multiple-user access of software, most software vendors sell network versions of their software. In this case, software vendors issue a site license, a legal agreement that allows multiple users to run the software package simultaneously. The site license fee is usually based on the number of users or the number of computers attached to the network. Sharing software via a network typically costs less than buying individual copies of the software for each computer. 4. *Transferring Funds*: Electronic funds transfer (EFT) allows users connected to the internet (an example of a Wide Area Network) to transfer money from one bank account to another via transmission media. Consumers can use credit cards or online payment systems such as PayPal to make  purchases over the internet. Businesses can use the internet to deposit employees’ salaries directly into their bank accounts. Both businesses and consumers pay bills online, which allows them to use EFT payments to pay creditors. Global networks also allow online retailers to trade continuously, without interruption. #### Conclusion In summary, networks provide numerous benefits, including hardware and software sharing, data access, and efficient financial transactions, making them essential for individuals and organizations operating in a global environment. However, the associated risks must be carefully managed to ensure the security and integrity of networked systems. ### Health Records Act 2001 (Victoria) The *Health Records Act 2001* regulates the confidentiality of patients' healthcare information in Victoria, as discussed in Chapter 6. The 11 Health Privacy Principles are summarized in Table 6.2 on page 238. #### Key Provisions: - *Confidentiality Protection*: The Act ensures that patients' healthcare information can only be used for the primary purpose for which it was collected. This means medical test results and medical history can only be accessed by healthcare providers (e.g., doctors, hospitals) for immediate or ongoing care. - *Consent Requirement*: Personal healthcare information cannot be disclosed to third parties (such as medical insurance companies or other hospitals) for secondary purposes without the patient's consent. - *Limited Circumstances for Disclosure Without Consent*: Health information may be shared without consent under specific, strictly limited circumstances, including: - Emergency requests from family members when the patient cannot consent and their life is in danger. - Serious threats to public health and welfare. - Research in the public interest. - Investigations of unlawful activity. - Legal claims.  - *Complaints Process: Individuals who believe their rights under the Health Records Act have been violated can file a complaint with the **Health Services Commissioner*. The Commissioner will facilitate discussion between the parties to resolve the issue. If a satisfactory resolution is not achieved, the Commissioner may issue a compliance notice to the organization that breached the Act, specifying the violation and requiring corrective action. - *Penalties*: The maximum penalty for organizations that violate the Act is 3,000 penalty units, while non-corporate cases may incur a penalty of 600 penalty units. ### Ethical Issues in Computer Networking Access to computer networks allows individuals to access substantial confidential data, yet training for computer specialists often lacks emphasis on privacy and ethical considerations, unlike fields such as medicine and law. #### Key Ethical Questions for Computer Professionals: 1. Should you read users' emails? 2. Should you monitor websites visited by users? 3. Should you install keyloggers to capture user input? 4. Should you read documents stored on users' computers or file servers? 5. Should you view graphics stored on users' computers or file servers? ### Professional Responsibility Computer professionals with network access bear significant responsibility. The computing profession, still developing, lacks a universally accepted code of ethics, making it essential to address these ethical dilemmas to maintain trust and integrity in the field.