If a network wants maximum throughput with minimal delay, which switching method is preferred?

• A. Cut-through
• B. Store and Forward
• C. Fragment-Free
• D. Forward Filter Decision

Answer: (A)

The main idea is latency. To get maximum throughput with the smallest delay, you want the switch to forward a frame as soon as it has enough information to decide where to send it, without waiting for the entire frame to be received and checked.

Cut-through switching does exactly that. It starts forwarding as soon as the destination MAC address is read from the frame header, so the switching decision happens quickly and the frame begins moving toward its destination while the rest of the frame is still arriving. This keeps the switch’s forwarding path busy, reducing end-to-end delay and boosting throughput, especially in high-speed networks.

The trade-off is that the switch isn’t verifying the entire frame for errors before forwarding, so a frame with a late-appearing error can still be sent onward. In contrast, store-and-forward waits until the whole frame is received and a CRC check passes, which adds latency but ensures only good frames get forwarded. Fragment-free is a middle-ground approach that checks a portion of the frame (the header) before forwarding, offering some error protection with lower delay than store-and-forward but more than cut-through. Given the goal of maximum throughput with minimal delay, cut-through is the best fit.