Suppose there is exactly one packet switch between a sending user and a receiving user. The transmission rates between the sending user and the switch and between the switch and the receiving user are R1 and R2, respectively. Assuming that the switch uses store-and-forward packet switching, what is the

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what is the total end-to-end delay to send a packet of length L? (Ignore queuing, propagation, and processing delay) extend to N-1 packet switches interconnected by N links with rates R1, R2, …, RN

L/R1 + L/R2

Explanation:

The sending host will begin to transmit at to

At ( t1 = L/R1 ) the entire packet will be received at the router because at this time the sending host will complete the transmission process  to the router.( No propagation delay )

At ( t2 = L/R2 ) the router completes transmission of the entire packet to the receiving host ( note : The transmission of the packet to the receiving host by the router starts at t1 hence No propagation delay is recorded. )

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