2023 internet service past paper Flashcards
(8 cards)
) For each of the following layers of the internet protocol stack, describe the
services it provides and give one example of a protocol in that layer:
i. the application layer
The application layer is the top layer of the Internet protocol stack. It provides network services directly to user applications, such as web browsers, email clients, and file transfer programs. This layer enables applications to communicate over the network using specific protocols.
An example of a protocol in this layer is HTTP (HyperText Transfer Protocol), which is used for requesting and delivering web pages between a client (like a browser) and a server.
What is the Transmission Control Protocol (TCP)? What is the User
Datagram Protocol (UDP)? Explain their similarities and differences.
[10 marks]
Transmission Control Protocol (TCP) is a connection-oriented protocol used to send data across a network in a reliable and ordered manner. Before data is transmitted, TCP establishes a connection between the sender and receiver through a handshake process. It ensures that all data packets arrive correctly and in the right order, using features like error checking, retransmission of lost packets, and flow control. TCP is commonly used for applications where accuracy is critical, such as email, web browsing, and file transfers.
User Datagram Protocol (UDP) is a connectionless protocol that sends data without establishing a connection first. It does not guarantee delivery, order, or error checking of packets. As a result, some data may be lost during transmission. However, UDP is much faster and more efficient than TCP, making it suitable for time-sensitive applications where speed is more important than perfect accuracy, such as online gaming, video calls, and live streaming.
The main similarities between TCP and UDP are that both operate at the transport layer of the Internet protocol stack and are used to transmit data between devices. However, the differences lie in how they handle reliability and speed: TCP focuses on reliability, while UDP prioritizes low latency and speed.
What is the purpose of using style sheets as part of a web document?
css stylesheet is used for presentation and layout of the webpage using css we can specify the background colour. where as html is used for the structure
Explain the role of the selector in a CSS style rule.
The selector in a CSS style rule specifies which HTML element(s) the style will apply to. For example, in h1 { color: blue; }, the selector h1 targets all <h1> elements and makes their text blue.
) Suppose, in an HTML document, that styles are specified in each of the
following ways: in a document-level style; in an external stylesheet; and
using an inline style. In which order would styles for a given element of the
document be applied by the web browser? [3 marks]
When multiple styles apply to the same element, the browser follows a priority order. Inline styles (inside the HTML tag) have the highest priority, followed by document-level styles (in a <style> block), and finally external stylesheets have the lowest priority. The closer the style is to the element, the more it overrides others.</style>
) Describe two differences between packet-switching networks and circuitswitching networks. Use examples to explain your answer.
packet switching networks. is when the data is split into smaller packets and sent across the network where they would be reassembled. the data could take many different pathways. if one path is disrupted than the data could be redirected along a different path. an example is the internet. circuit switching network is when a connection is established and remain open until the session ends. an example could be a phone call. the downside is that it could be a waste of resource as no data could be transeffered but the connection is still active
) Consider the protocol TCP (the Transmission Control Protocol).
i. How can a TCP connection be established? Use an example to explain
your answer.
Steps of the Three-Way Handshake:
SYN (Synchronize): The client sends a SYN packet to the server, requesting to establish a connection.
SYN-ACK (Synchronization Acknowledgment): The server responds with a SYN-ACK, acknowledging the request
ACK (Acknowledgment): The client then sends an ACK packet back to the server, completing the handshake. At this point, the connection is fully established, and data transfer can begin.
