A data-switching strategy that requires no physical path to exist between sender and receiver before communication can take place. Message switching passes messages via relays, called switching offices, in a store and forward network. Each switching office receives a message, checks it for errors, and retransmits it to the next switching office on the route to the destination. Because of the large buffers and variable delays of message switching, most computer networks use packet switching or circuit switching techniques for their underlying network components, and add message switching functions (such as email and file transfer protocol) at higher levels.