Consider a packet of length L that begins at end system A and travels over

three links to a destination end system. These three links are connected by

two packet switches. Let di$,$ si$,$ and Ri denote the length, propagation speed,

and the transmission rate of link i$,$ for i $=1,2,3.$ The packet switch delays

each packet by dproc. Assuming no queuing delays, in terms of di

$,$ si

$,$ Ri$,$

$($i $=1,2,3),$ and L$,$ what is the total end$-$to$-$end delay for the packet? Suppose now the packet is $1223$ bytes, the propagation speed on all three links is

$2\mathrm{.}510^8$

m$/$s$,$ the transmission rates of all three links are $2\mathrm{.}5$ Mbps$,$ the packet

switch processing delay is $3$ msec, the length of the first link is $5,000$ km$,$ the

length of the second link is $4,000$ km$,$ and the length of the last link is $1,000$

km$.$ For these values, what is the end$-$to$-$end delay?