Input Devices: send data into a computer system. Often used by people to interact with computers. E.g. a mouse

Output Devices: send data from a computer system to a user, or another computer system. E.g. monitor

Communication methods - https://trinitynewbury.fireflycloud.net/it-1/unit-1---584001/lo2/communication-methods

Operating systems -
https://trinitynewbury.fireflycloud.net/it-1/unit-1---584001/lo2/operating-systems

Utility software - https://trinitynewbury.fireflycloud.net/it-1/unit-1---584001/lo2/utility-software

Application software - https://trinitynewbury.fireflycloud.net/it-1/unit-1---584001/lo2/application-software

Types of software - https://trinitynewbury.fireflycloud.net/it-1/unit-1---584001/lo2/types-of-software

Mechanical: Each key is connected individually.

Membrane: a "membrane" covers the surface under all keys, which detects which key(s) have been pressed.

Modem: a hardware device that connects a computer or router to a broadband network. A modem takes the digital signals from a computer system and converts them into analogue for sending. Once received, it then converts these signals back into digital signals.

Network Interface Card (NIC) responsible for sending packets of data across a network.

• It's connected to the motherboard
• allows connection to a network via Wi-Fi or Ethernet cable.
• each has a globally unique address- the MAC address- (48bits)

UDP:

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• Protocol type: Connectionless.
• Reliability: Doesn't guarantee packet delivery.
• Error-checking: Uses checksums for basic error detection.
• Overhead: Minimal header overhead, making it lightweight.(Not many directions).
• Ordering: Doesn't guarantee ordered delivery of packets.
• Port Numbers: Utilises port numbers for addressing and data differentiation.
• Uses: for streaming services(where data has to be sent quickly rather than making sure it's perfect.)

IP(Internet Protocol)

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• When data is sent over a network, IP is responsible for adding the destination address to each data packet and adding its own address(source address) to indicate where the packet originated from.
• When data is received over a network, the IP is responsible for accepting data packets which have its own address attached, but ignoring all others.

TCP(Transmission Control Protocol)

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• Prepares messages for transmission and also reassembles any messages that are recieved('packet switching').
  - To send data over a network the TCP:
  -Divides the message into smaller data packets.
  -Adds a sequence number to each packet so that it can be reassembled after delivery
  -Adds error correction informaton so that errors can be spotted and fixed.
  - To recieve data over a network the TCP:

SNMP(Simple Network Management Protocol)

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• Purpose: Designed for network monitoring and management.
• Components: SNMP has two primary components:
  
  • agents (reside on network devices)
  • the management system (monitors and controls agents).
    

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• Uses:
  
  • Monitor Device Performance: SNMP provides real-time data on the performance of network devices. *This includes metrics like bandwidth usage, error rates, and uptime.
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  • Health Check & Diagnostics: Through SNMP, administrators can quickly gauge the health and operational status of network devices, identifying potential issues or bottlenecks.
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  • Configuration Management: Beyond passive monitoring, SNMP allows remote configuration of network devices. Administrators can make changes to a device's settings or even reboot it remotely.
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  • Receive Alerts: When certain predefined conditions or thresholds are reached, SNMP agents send "traps" to the management system, alerting administrators to potential issues in real time.
    
    

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• Benefits of Using SNMP:
  
  • Scalability: SNMP can be used to manage small home networks or large enterprise networks with thousands of devices.
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  • Interoperability: Given its standardized nature, SNMP offers interoperability among various hardware and software vendors. Devices from different manufacturers can be managed using a single SNMP management system.
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  • Proactive Management: With the trap functionality, SNMP allows for proactive network management. Instead of waiting for issues to become noticeable, administrators are alerted at the first sign of trouble.
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  • Resource Efficiency: SNMP provides a centralized way of managing multiple devices. This reduces the need for manual checks and onsite visits, saving time and resources.
    

Router: A device which connects networks together across the Internet.

• It manages data packets by determining the shortest path to their destination network.
• Algorithms are used to determine the quickest journey time.
• They maintain a table of neighborhood networks which can be shared.
• Home routers connect to their ISP, which manages the transmission of packets.
• Larger organisations manage the transmission of packets themselves.

Hub: A small box which links nodes on a network. Transmits data "packets" between nodes. Insecure: when a packet arrives to a hub, it gets forwarded to all connected nodes. Causes a lot of data collisions.

Switch: allows a larger amount of computers to be linked to share data. allows a larger amount of computers to be linked to share data. Less collisions & more secure: Packets are sent only to the destination node. Much more expensive than a hub.

Router: Transfers data between networks. Essential to connect a LAN to a WAN such as the Internet. It looks up the packets' IP address and sends it to the destination via the best route available at that moment.

Event Log Viewer:

• Use: To capture and display system events and error.
• How it works: