$4.$ To send packets to its destination, a source host $($Host $1)$ must send packets through $2$ Routers to research

the destination host at the other end of the connection $($Host $2).$ Supposed Host $1$ wants to transmit a

$10,000$Byte packet to Host $2.$

Assume the following:

$$ The hosts, switches and routers are connected by $1$Gbps links.

$$ The packet size is $10,000$Bytes with $70$Bytes overhead.

$$ The links are $1$km coaxial cable links $($signal speed $2\mathrm{.}6*10^(8)$ m$/$s$).$

$$ The processing delay is negligible.

$$ Each time one of Host $1$s packets arrive at Router $1,3$ packets $($from other hosts connecting through

the same router$)$ arrive at the same time. Assume the buffers are infinite $($no lost packets$).$

$$ When needed, the setup delay is $5$microseconds.

a$.$ Sketch the network topology.

b$.$ Calculate the total delay for: $($i$)$ Circuit$-$switched network, $($ii$)$ Packet$-$switched network, $($iii$)$

Virtual$-$circuit switched network