3. [20 pts.] In a packet-switched network, the source host segments a long message into smaller packets and sends the packets into the network. The receiver then reassembles the packets back into the original message. The figure below illustrates the end-to-end transport of a message: (a) without message segmentation, and (b) with message segmentation. Assume the following: message size is M = 8 x 106 bits, transmission rate for each link is R = 2 Mbps. The propagation, queuing, and processing delays are negligible. Also assume that each switch uses store-and- forward switching approach. a. Consider sending the message from source to destination without message segmentation. What is the total time to move the entire message from source host to destination host? b. Consider segmenting the message into 800 packets. What is the total time to move the entire message from source host to destination host? c. Present two reasons for message segmentation. d. Discuss two drawbacks of message segmentation. Message a. Source Packet switch Packet switch Destination Packet b. Source Packet switch Packet switch Destination