Circuit switching, packet switching — common mistakes

In exam questions, you will often be asked to compare these two methods. Use comparative words like 'whereas', 'on the other hand', and 'in contrast'. Structure your answer around key criteria: connection setup (dedicated vs. connectionless), resource allocation (reserved vs. on-demand), robustness, and suitability for different data types (e.g., real-time voice vs. bursty web traffic).

No, they are suited for different purposes. Circuit switching is excellent for applications needing a constant, reliable connection with no jitter, like traditional telephone calls. Packet switching is far more efficient and robust for the varied, 'bursty' nature of internet traffic, where many users share the same infrastructure.

The header of each packet contains a sequence number. The receiving device's transport layer protocol (like TCP) uses these numbers to place the data from the payloads back into the correct order before passing the complete message to the application.

Reliable protocols like TCP (Transmission Control Protocol) handle this. The receiver sends acknowledgements (ACKs) for packets it receives correctly. If the sender doesn't receive an ACK for a particular packet within a certain time, it assumes the packet was lost and retransmits it.

While the underlying core networks of most telephone providers have transitioned to packet switching (using technologies like VoIP), the concept of a dedicated circuit still exists in specialised high-end services like leased lines, which guarantee a certain bandwidth between two points for a high price.