Network Communications Module Flashcards
What is the application layer
Provides network services directly to end-user applications
Applications interact with the network, where applications are able to communicate with each other, and are able to access the network.
What are the protocols of the application layer
HTTP (Hypertext Transfer Protocol): Used for web browsing
FTP (File Transfer Protocol): Used for file transfers
SMTP (Simple Mail Transfer Protocol): Used for email transmission
DNS (Domain Name System): Resolves domain names to IP addresses
What is the transport layer
Ensures data is transferred reliably end-to-end, from one device to another
Manages error detection and connection. Divides data into packets, and manages flow control
What are protocols of transport layer
TCP (Transport Communication Protocol): Reliable, connection-oriented communication
UDP (User Datagram Protocol): Faster, connectionless communication with no error checking
What is the internet layer
Wraps data packets in an IP frame, that contains the source address and destination address
Uses the information to route and forward the data packets across network
Where it uses the IP protocol to address and route.
What are protocols of internet layer
IP (Internet Protocol): Provides logical addressing
ICMP (Internet Control Message Protocol): Used for error messages and operational information
ARP (Address Resolution Protocol): Maps IP addresses to physical MAC addresses
What is the network layer
Handles physical transmission of data on the network, and the physical connection of devices on network.
Defines hardware addressing and the physical network medium
What are protocols of the network layer
Physical Medium: Cable types, and wireless standards
MAC (Media Access Control) Address: Unique identifier for network interfaces
Ethernet, Wi-Fi, Point-to-Point Protocol
What is the role of ip addresses
Unique identifier assigned to each device on network
Allows devices to identify each other and communicate across a network
Identifies the host, and provides location of host in network
Capability to establish a path to host
What is key differences between IPv4 and IPv6
IPv6 has 128-bit address, IPv4 has 32-bit address = Larger address space
IPv4 addresses numeric, IPv6 address alphanumeric using hexadecimal notation
IPv6 has enhanced security
IPv6 has simplified header structure
What is role of subnet masks
Separates IP addresses into network & host parts
Determine which part of IP address identifies host, which part identifies to network which it belongs
What is subnetting
Practice of dividing network into two or more smaller networks (Subnets)
Optimise network performance, improve security, make network management easier
How does subnetting improve network performance
Reduces congestion, increases bandwidth availability, minimises excess broadcast traffic
Simplifies troubleshooting by isolating issues to specific subnets
How does subnetting improve data security
If unauthorised access on network, restricts intruders from moving laterally across entire network, contains breaches to specific subnet
Network admins can implement security policies and access controls for each subnet, ensuring information remains protected, privacy is maintained
What is UTP in transmission media
Used in ethernet networks, cost-effective, easy to install
Lower bandwidth, higher latency
What is fibre optics in transmission media
High bandwidth, lower latency, can cover long distances without degradation
Expensive, specialised equipment for installation
What is wireless in transmission media
Electromagnetic waves to transmit data through air
Wi-Fi, satellite, cellular technologies
Mobility, ease of deployment, may be affected by environmental factors
Lower bandwidth, higher latency
What are routers
Internet layer, routing packets of data between different networks based on their IP addresses
Determines best path for data to travel using routing protocols
What is a switch
Network layer, connect devices within a single network
Uses MAC addresses to forward data frames to correct destination within local network
- Only operates in local network
Reduces amount of collision domains, improving performance
What is a wireless access point (WAP)
Network layer, wireless devices connect to wired network using Wi-Fi
Extend wireless coverage of network, manages multiple connections simultaneously
What is a firewall and its role
Internet layer, monitors & controls incoming & outgoing network traffic based on predetermined security rules
Intercepts all messages entering & leaving network, filters packets by blocking harmful data packets
Tracks state of active connections
What is risks of unauthorised access in network security
Data theft, information like personal data, financial details, IP
System damage
Legal and compliance issues, loss of reputation and penalties
What is preventation strategies of unauthorised access in network security
Use strong authentication methods
Regular updating & patching of software
What is role of operating systems in network security
Control user access to network resources through user credentials & permissions
Monitors the system for vulnerabilities and analyses patterns for anomalies, providing regular software updates to stop attacks from happening
Malware protection, anti-malware and anti-virus tools
What is bandwidth as factors that affect network performance
Rate at which data can be transferred over network at any given time
Higher bandwidth = More data transferred simultaneously
Low bandwidth = Slow data transfer rates
What is network design as factors that affect network performance
Bus, Star, Ring, Mesh, Hybrid
Efficient design reduces bottlenecks, enhances data flow, higher data rates
Poor design leads to packet loss, low network efficiency, data collisions
What are data collisions as factors that affect network performance
When two devices send packets simultaneously on same network segment, causing packets to collide & corrupt
Collisions lead to congestion, reduced network speed
Collision detection minimises issues
What is excess broadcast traffic as factors that affect network performance
Sending data to all network devices, regardless of intended device
Overwhelm network resources = Network slowdown
Managing & limiting broadcast traffic maintains optimal performance
What are network diagrams
Draw network diagrams, represent topologies for LAN, WLAN, WAN
Symbols given in exam
What are connections in network diagrams
Solid lines = Ethernet
Dotted lines = Wireless
Each connection line should be labelled with type
What is a bus in network topologies
All devices share a common single communication line or a bus
Only one node can send / receive data at a time
What is a ring in network topologies
All nodes connected on a medium, if a node wants to send data, adds it to the frame
What is a star in network topologies
All devices connected to single central device, typically switch or hub
What is a mesh in network topologies
Devices interconnected directly with many redundant interconnections between network nodes
What is a hybrid in network topologies
Mixture of all types of topologies
