Circuit, Datagram and Virtual Circuit
Circuit switching, datagram packet switching and virtual-circuit packet switching compared on setup, path, ordering, resource sharing, per-packet header and router state. Timing formulas for a circuit (setup plus transfer at the circuit rate, including TDM slots), for message switching and for pipelined packet switching over k store-and-forward links, the header trade-off that gives an optimal packet size, and the setup cost that decides between a virtual circuit and datagrams. Every number checked by script, with a solved 2024 past question.
