9618 · 14.2
Circuit switching, packet switching — FAQ
Frequently asked questions for 9618 Circuit switching, packet switching. Direct answers first, then deeper explanation — then practise with marking.
Is one switching method objectively better than the other?
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.
How do packets get reassembled in the correct order if they arrive out of sequence?
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.
What happens if a packet gets lost or corrupted?
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.
Does circuit switching still exist?
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.