Q3 In modern packet-switched networks, 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. Message Packet switch Destination a. Source Packet switch Packet b. Source Packet switch Packet switch Destination Figure 1.27End-to-end message transport: (a) without message segmentation; (b) with message segmentation Assume we have a source A and a destination B, connected via three links and two switches S1 and S2. A connects to S1, S1 to S2, and S2 to B We will consider two case where a message is sent from A to B with and without message segmentation. Consider a message that is L-7.5 x 106 bits long that is to be sent from A to B in the following manner. And suppose each link R-1.5 x 106 bps. For the time being, ignore propagation, queuing, and processing delays. 1. Consider sending the message from A to B without message segmentation. How long does it take to move the message from the host A to the first packet switch S1? Keeping in mind that each switch uses store-and-forward packet switching, what is the total time to move the message from A to B? 2. Now suppose that the message is segmented into 5,000 packets, with each packet being 1,500 bits long. How long does it take to move the first packet from A to the first switch S1? 3. When the first packet is being sent from the first switch S1 to the second switch S2, the second packet is being sent from the A to the first switch S1. At what time will the second packet be fully received at the first switch S1? 4. How long does it take to move the file from A to B when message segmentation is used