Lecture 1 - HTML Flashcards
1
Q
Characteristics of Circuit-Switched Networks
A
- Constant Bandwidth: The circuit provides a fixed amount of bandwidth, which remains constant for the duration of the connection.
- Latency: The dedicated nature of the circuit ensures low and predictable latency, as the path does not change during the call.
- Resource Allocation: Resources (such as bandwidth) are allocated for the entire duration of the connection, even if no data is being transmitted (e.g., periods of silence during a phone call).
2
Q
Circuit Switched Networks - Circuit Establishment
A
- Dedicated Path: In a circuit-switched network, a dedicated communication path is established between the caller and the receiver for the duration of the call. This path is exclusively reserved, ensuring a consistent and continuous connection.
- End-to-End Connection: Once the circuit is established, the connection remains active and dedicated until the call is terminated.
3
Q
Circuit - Switched Networks - Manual Switching
A
- Operators: Telephone calls were initially routed through human operators. When a person wanted to make a call, they would pick up the phone and speak to an operator. The operator would then connect the caller and the receiver by physically plugging a wire into a switchboard to complete the circuit.
- Switchboards: These were large panels with numerous jacks and plugs that operators used to connect calls manually.
4
Q
Evolution of Circuit Switching
A
1. Automated Switching:
- Electromechanical Switches: Over time, manual switchboards were replaced with electromechanical switches, which automated the process of establishing circuits without human intervention.
- Digital Switching: Eventually, digital switches further enhanced the efficiency and capacity of circuit-switched networks.
2. Transition to Packet Switching:
5
Q
Circuit - Switched Networks - Limitations
A
- Inefficiency: Circuit-switched networks can be inefficient, especially when the connection is not continuously used (e.g., pauses in conversation). The reserved resources cannot be used by other users.
- Scalability: As the number of users increases, the network must accommodate a growing number of dedicated circuits, which can lead to scalability issues.
- Bandwidth Constraints: Limited bandwidth resources can become a bottleneck, especially with a large number of simultaneous connections.
6
Q
Packet-Switched Networks
A
- Modern networking has largely moved to packet-switching, where data is broken into packets and routed over shared networks.
- This approach is more efficient and scalable, allowing multiple users to share the same network resources dynamically.
- Does not require a continuous connection.
- 1981 TCP/IP was introduced to unify disparate networks
7
Q
Web App vs Desktop App - Accessiblity
A
- Can be accessed from any internet enabled device
- Typically need to be installed on each deviice
8
Q
Web App vs Desktop App - Cross Platform
A
- Compatible with different operating systems and browsers
- Often specific to one OS
9
Q
Web App vs Desktop App - Ease of Updates
A
- Easier to roll out updates ince only server-side needs updating
- Updates need to be installed locally
10
Q
Web App vs Desktop App - Storage
A
- Centralised storage on the server, reducing local storage needs
- Data is usually stored locally on each device
11
Q
Web App vs Desktop App - Internet Dep.
A
- Requires an active internet connection
- Can often be used offline
12
Q
Web App vs Desktop App - Security Concerns
A
- Risks with transmitting sensitive data over the internet
- Reduces transmission risk, due to locality
13
Q
Web App vs Desktop App - Data Control
A
- Concerns over the storage and use of uploaded data
- Users typically have more control over their data
14
Q
Web App vs Desktop App - Cross-Browser Compatibilty
A
- Websites may not render identically across all browsers
- Appearance and functionality usually consistent across platforms
15
Q
Web App vs Desktop App - Installation Restrictions
A
- Limited ability to install software or access hardware directly
- Full access to system resources and hardware