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Q2. Choose the switching type that has the lowest latency?
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A. Fragment-Free B. Store-and-Forward C. Cut-through D. Connect-On
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Correct answer: C
Explanation:
Store-and-Forward switching: Here the LAN switch copies the entire frame into its buffers and computes the CRC. The frame is discarded if there are any CRC errors. Giant ( more than 1518 bytes0 and Runt (less than 64 bytes) frames are also dropped, if found.
Cut-Through (Real-Time) switching: Here, the LAN switch copies only the destination address into its buffers. It immediately looks up the switching table and starts forwarding the frame. The latency is very less because, the frame is forwarded as soon as the destination address is resolved.
Fragment-Free switching: Here, the switch waits for the collision window before forwarding the entire frame. The collision window is 64 bytes long.
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