Question $1.$ How long does it take a packet of length $1,000$ bytes to propagate over a link of

distance $2,500km,$ propagation speed $2\mathrm{.}5108*\frac{m}{s},$ and transmission rate $2$ Mbps $?$

The Answer Is:

More generally, how long does it take a packet of length $L$ to propagate over a link of distance $d,$

propagation speed $s,$ and transmission rate $R$ bps$?$

The Answer Is:

Question $2.$ Consider a packet of length $L$ that begins at end system A and travels over three

links toa 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 $d$ proc.

Assuming no queuing delays, in terms of $di,$ si$,Ri,),$ and $L,$ what is the total end$-$to$-$end

delay for the packet?

The Answer Is:

Suppose now the packet is $1,500$ bytes,, the propagation speed on all three links is $2\mathrm{.}5*108\frac{m}{s},$

the transmission rates of all three links are $2$ Mbps $,$ the packet switch processing delay is $3$ msec $,$

the length of the first link is $5,000km,$ the length of the second link is $4,000km,$ and the length

of the last link is $1,000km.$

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

The Answer Is: