advantages and disadvantages? $(2$ points$)$

$3.$ Suppose there is exactly one packet switch between a sending host and a receiving $1$ The transmission rates between the sending host and the switch and between the sw and the receiving host are $R_1$ and $R_2$ respectively $($see figure below$).$ Assuming that switch uses store$-$and$-$forward packet switching, what is the total end$-$to$-$end delay send a packet of length $L?($Ignore queuing, propagation delay, and processing delay $(2$ points$)$

Source

Front of packet $1$

Destination stored in router, awaiting remaining bits before forwarding