$1.$ In modern networking, such as the Internet, the process of breaking down large

application$-$layer messages, like images or music files, into smaller packets at the source

host is crucial. These packets are then transmitted through the network and

reassembled into the original message at the receiver. This procedure is known as

message segmentation. Let's examine a scenario involving an $8$x$106$ bits long message to

be transmitted from a source to a destination. Assuming each link in the network

depicted has a capacity of $4$ Mbps$,$ and for simplicity, we'll ignore propagation, queuing,

and processing delays. Assume $1$ Mbps $=1$x$106$ bps$.$

a$.$ Imagine transmitting the message from the source to the destination without

message segmentation. Given that the switch utilizes store$-$and$-$forward packet

switching, determine the total time required to move the message from the

source host to the destination host?

b$.$ Now, let's consider that the message has been divided into $800$ packets, with

each packet containing $12,000$ bits. Calculate the time required to transfer the

file from the source host to the destination host when utilizing message

segmentation?

c$.$ Contrast the outcomes obtained from your responses in parts $($a$)$ and $($b$).$

d$.$ Enumerate two advantages and disadvantages of employing message

segmentation?

$2.$