$($a$)($i$)$ Describe circuit switching mode of data transmission.

$($ii$)$ State two demerits of the switching mode in $($i$).$

$(6$ marks$)$

$($b$)$ A transmission link is described by the following:

$4$ hops $($point$-$to$-$point links$)$ between two terminal nodes;

Transmission rate of $9,600bps$ on all links;

$24$ overhead bits $($header $+$ trailer$)$ for each packet of size $1024$;

$1ms$ per$-$hop signal propagation delay;

$1$ second call set$-$up time for circuit switched connection across $4$ hops;

For a message size of $5,000$ bits, determine the total transmission time in case of:

$($i$)$ circuit switching;

$($ii$)$ message switching.

$(12$ marks$)$

$($c$)$ List two tools used in structured cabling.

$(2$ marks$)$

SECTION B: NETWORKING

Answer at least TWO questions from this section.

$($a$)($i$)$ Explain how the open system interconnection $($OSI$)$ model facilitates the standard making process.