Video Notes: Network Architecture and Security (2.1–2.3.6)

Question-and-answer flashcards covering network architecture, transmission media, topologies, network metrics, security, and related concepts from the lecture notes.

What are the key components of an organisation's IT infrastructure?

File servers, print servers, web servers, mail servers, database servers, application servers; network interface cards; repeaters; switches; routers; wireless access points; storage systems; end-point devices.

What is a file server?

A central server that provides access to file systems to clients on the network and allows centralized storage, access, and management of files.

Who manages access rights and permissions on a file server?

The server administrator.

Which protocols do mail servers typically use for sending and retrieving emails?

SMTP for sending; POP3 or IMAP for retrieval; outgoing mail servers (SMTP) handle delivery.

What is the role of a router in a network?

A device that connects multiple networks and routes data packets using routing tables and IP addresses.

What is on-premise computing?

An onsite IT infrastructure owned and maintained by the organisation, offering customization and control but requiring dedicated resources for maintenance and security.

What is cloud computing?

On-demand IT services over the internet, offering scalability and accessibility with managed services by a third-party, but may involve reliance on external servers and data security considerations.

Define bandwidth.

The capacity of data that can be transferred per unit time on a transmission medium, measured in bits per second.

What is shielding in wired transmission media for?

To prevent or limit external electromagnetic interference from affecting the signal, reducing interference and degradation.

Differentiate twisted pair and coaxial cable.

Twisted pair: copper wires twisted together; economical and common. Coaxial: central conductor with shielding; better protection but may require signal boosters for long distances.

What is a key advantage of fiber-optic cable?

Higher data transfer rates and longer distances; immune to external electrical interference; uses light to transmit data.

What is satellite communication used for?

A wireless transmission medium using satellites to transmit/receive data; used for long-distance communication, TV broadcasting, GPS, and satellite internet.

What happens to wireless signal strength as distance increases?

Signal strength decreases, leading to degradation, higher latency, and potential packet loss.

How does the physical structure of a building affect wired networks?

It influences cable layout and propagation; obstacles like walls and floors can impede signal propagation and reduce speeds.

What are common physical barriers in wireless transmission?

Walls, floors, ceilings that obstruct or weaken radio waves, reducing signal strength and coverage.

Name environmental barriers that can affect wireless signals.

Electromagnetic interference (EMI) and radio frequency interference (RFI) from devices or power lines, plus atmospheric conditions like rain or fog.

What are typical consequences of interference in a network?

Reduced transmission speed, higher latency, packet loss, poorer quality of service, and frustrated users.

Describe the three common network topologies and a key characteristic.

Star: central device, minimal disruption; Bus: less cabling but potential congestion and privacy issues; Ring: simple with less cabling but potential disruption and shared bandwidth.

What is the purpose of strategic device placement in networks?

To enable efficient data flow and optimize network performance.

What is traffic filtering in a network?

Selective allowing or blocking of traffic based on predefined criteria to improve security and bandwidth usage.

What does traffic monitoring involve?

Capturing, examining, and interpreting network traffic to assess performance, security, and usage.

What is flow scheduling in networks?

Determining the order and priority of data packets by assigning time slots or priorities to different data flows to improve efficiency and fairness.

Define adjacency in networking.

The direct connection between two nodes, indicating direct links between devices like routers or switches.

What is centrality analysis in networks?

Identifying the most important or influential nodes to optimize routing, resource allocation, and traffic flow.

What is connectedness in graph theory?

A property where all nodes are reachable from any other node via a path of edges, ensuring connectivity and fault tolerance.

What are weighted graphs used for in networks?

Edges have weights representing factors like bandwidth, latency, distance, or cost to optimize routing and load balancing.

In the provided network example, what are the radius and diameter, and which nodes are central?

Radius = 2; Diameter = 4; central nodes are B and F.

Which nodes are peripheral in the provided network example?

Nodes A, G, and H.

Which node has the highest degree in the example network, and what is its degree?

Node E has the highest degree, which is 4.

What does the adjacency imply about E in the example network?

E is considered the most important node due to its high degree (adjacency significance).

What does the connectedness matrix indicate about node connectivity in the example?

All nodes are highly connected overall, with B, C, D, and F slightly better connected than A, E, G, and H.

Give two examples of biometric measures used for authentication in network security.

Fingerprint scanning and facial recognition.

What is CAPTCHA and its purpose?

A test to distinguish humans from automated bots, often using distorted letters or images.

What is the Trusted Platform Module (TPM)?

Hardware-based protection that stores cryptographic keys and enables features like encryption and secure boot.

Why are automatic software updates important for security?

They promptly install patches and fixes to address vulnerabilities in OS, software, and devices.

Why are regular data backups and disaster recovery plans important for home networks?

They prevent data loss and enable quick restoration of functionality and data integrity after failures or breaches.