[CS] Understanding Packet Switching: Virtual Circuit and Datagram Methods with Quiz

1. What term describes the number of unique values in a specific dataset?
   • Explanation: Cardinality refers to the distinct count of values within a dataset, indicating how many unique values exist.
2. What term is used to describe the actual set of data stored in a database table?
   • Explanation: A relation instance is the concrete collection of data stored within a database table, also known as the relation or extension.
3. In the context of databases, what does a tuple represent?
   • Explanation: A tuple refers to a single row or record within a database table, containing data fields corresponding to the table’s attributes.
4. Which protocol is used to send error messages and operational information in IP networks?
   • Explanation: ICMP is essential for network troubleshooting by reporting errors and providing feedback on IP packet transmission.
5. What term describes a program that self-replicates and spreads to other computers through network connections?
   • Explanation: A virus is a type of malware that replicates itself and spreads to other computers by attaching to host files or through network transmissions.
6. Which protocol provides secure remote access to a computer or server, offering stronger security than Telnet?
   • Explanation: SSH encrypts communication sessions between computers, providing secure remote access and file transfer capabilities.
7. What term describes a unit of data transmitted independently over a network without establishing a connection?
   • Explanation: A datagram is a self-contained packet of data sent across a network without a prior setup of connection paths, commonly used in packet-switched networks.
8. In networking, what is a pre-defined logical communication path between sender and receiver stations called?
   • Explanation: A virtual circuit is a predetermined logical route in packet-switched networks, ensuring ordered and reliable data transmission between endpoints.
9. What web development technique enables asynchronous loading of web page content, allowing users to interact with web pages more dynamically?
   • Explanation: AJAX facilitates updating specific parts of a web page without refreshing the entire page, enhancing user interaction and responsiveness in web applications.
10. What term describes a program that appears benign but performs malicious actions when executed?
    • Explanation: A Trojan horse disguises itself as legitimate software to deceive users into executing harmful actions.
11. Which protocol is used to send error messages and operational information in IP networks?
    • Explanation: ICMP is essential for network troubleshooting by reporting errors and providing feedback on IP packet transmission.

Understanding Packet Switching: Virtual Circuit and Datagram Methods

Packet switching is a method of transmitting messages by dividing them into packets of a certain length. This method is fundamental to modern networking and can be categorized into two types: virtual circuit switching and datagram switching.

Virtual Circuit Switching

Virtual circuit switching establishes a logical virtual communication circuit between terminals before transmission. Here’s how it works:

• Pre-established Route: A logical communication circuit is set up between the sender and receiver in advance, confirming the connection before transmission.
• Control Packets: The route is set by a control packet before any information is sent.
• Order Preservation: All packets are transmitted sequentially along the same route, ensuring that the order of transmission and reception is maintained.

Datagram Switching

Datagram switching, on the other hand, does not set a connection route. Instead, it relies on the current traffic conditions and independently handles each packet. Here are its key characteristics:

• No Pre-set Route: It does not establish a fixed connection route. Instead, it monitors the traffic status of accessible nodes and distributes packets accordingly.
• Independent Packets: Each packet may have a different transmission route and carries the complete address of the destination.
• Reordering at Destination: Packets might arrive at the destination through various routes and in different orders, requiring reordering at the receiving end.

Understanding the differences between virtual circuit switching and datagram switching is crucial for grasping how data is transmitted over networks. Each method has its unique advantages and is suitable for different types of network communication.