Problem 1. (16 points) Information about Internet protocol stack.

a. What are the five layers in the Internet protocol stack?

b. What is the packet called in each of layer of Internet protocol stack?

c. What are the principal responsibilities of each of these layers?

d. Which layers in the Internet protocol does a router process?

e. Which layers in the Internet protocol does a link-layer switch process?

f. Which layers does a host process?

g. What are the advantages of layered network architecture? h. What are the disadvantages of layered network architecture?

Problem 2. (10 points) Suppose two hosts A and B are separated by 10,000 kilometers and are connected by a direct link of R = 10 Mbps, Suppose the propagation speed over the link is 2 x 108 meters/sec

a. Calculate the bandwidth-delay product R x dprop.

b. Consider sending a file of 400,000 bits from Host A to Host B. Suppose the file is sent continuously as one large message. What is the maximum number of bit that will be in the link at any given time?

c. Provide an interpretation of the bandwidth-delay product.

d. How long does it take to transmit 1 bit? What is the width (in meters) of a bit in the link? Is it longer than a soccer field (105 meters)?

e. Derive a general expression for the width of a bit in terms of the propagation speed s, the transmission rate R, and the length of the link m.

Problem 3. (4 points) Consider sending a packet from a source host to a destination host over a fixed route.

a. List the delay components in the end-to-end delay.

b. Which of these delays are constant and which are variable? How does traffic intensity affect queuing delay and packet loss?

Problem 4. (20 points) In the 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. The figure below illustrates the end-to-end transport of a message with and without message segmentation. Consider a message that is 106 bits long that is to be sent from source to destination in the figure. Suppose each link in the figure is 2 Mbps. Ignore propagation, queuing, and processing delays. You may want to refer to the simulation at https://wps.pearsoned.com/ecs_kurose_compnetw_6/216/55463/14198702.cw/index.html

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? Keeping in mind that each switch uses store-and-forward packet switching, what is the total time to move the message from source host to destination host?

b. Now suppose that the message is segmented into 1,000 packets, with each packet being 1,000 bits long. How long does it take to move the first packet from source host to the first switch?

c. When the first packet is being sent from the first switch to the second switch, the second packet is being sent from the source host to the first switch. At what time will the second packet be fully received at the first switch?

d. How long does it take to move the file from source host to destination host when message segmentation is used? Compare this result with your answer in part (a) and comment.

a. Source b. Source Message Packet switch Packet Packet switch Packet switch Packet switch Destination SHEL Destination