1.What is the difference between a host and an end system? List several different types of end systems. Is a Web server an end system?
Why are standards important for protocols?
What is the transmission rate of Ethernet LANs?
What are some of the physical media that Ethernet can run over?
Describe the most popular wireless Internet access technologies today. Compare and contrast them.
2. (5 points) Consider sending a packet from a source host to a destination host over a fixed route. List the delay components in the end-to-end delay. Which of these delays are constant and which are variable?
3. (5 points) How long does it take a packet of length 1,000 bytes to propagate over a link of distance 2,500 km, propagation speed , and transmission rate 2 Mbps? More generally, how long does it take a packet of length L to propagate over a link of distance d, propagation speed s, and transmission rate R bps? Does this delay depend on packet length? Does this delay depend on transmission rate?
4. (5 points) Suppose Host A wants to send a large file to Host B. The path from Host A to Host B has three links, of rates , and .
a. Assuming no other traffic in the network, what is the throughput for the file transfer?
b. Suppose the file is 4 million bytes. Dividing the file size by the throughput, roughly how long will it take to transfer the file to Host B?
c. Repeat (a) and (b), but now with reduced to 100 kbps.
5. (5 points) Suppose end system A wants to send a large file to end system B. At a very high level, describe how end system A creates packets from the file. When one of these packets arrives to a router, what information in the packet does the router use to determine the link onto which the packet is forwarded? Why is packet switching in the Internet analogous to driving from one city to another and asking directions along the way?