Based on Problem P$31$:

In modern packet$-$switched networks, including the Internet, the source host

segments long, application$-$layer messages $($for example, an image or a music file$)$

into smaller packets and sends the packets into the network. The receiver then

reassembles the packets back into the original message. We refer to this process

as message segmentation. Figure $1\mathrm{.}27$ in our textbook illustrates the end$-$to$-$end

transport of a message with and without message segmentation. Consider a

message that is ${10}^6$ bits long that is to be sent from source to destination in

Figure $1\mathrm{.}27.$ Suppose each link in the figure is $5Mbps.$ Ignore propagation,

queuing, and processing delays.

$($a$)$ Consider sending the message from source to destination without message

segmentation. How long does it take to move the message from the source host

to the first packet switch? Give your answer as an integer in msec.

$($b$)$ Now suppose that the message is segmented into $100$ packets, with each

packet being $10,000$ bits long. How long does it take to move the first packet

from source host to the first switch? Give your answer as an integer in msec.

Recall that $1$msec$=0\mathrm{.}001sec$ and $1Mbps=1,000,000bps.$

$($a$)$

msec; $($b$)$

msec