Q1. List five nonproprietary Internet applications and the application-layer protocols that they use.
Q2. What information is used by a process running on one host to identify a process running on another host?
Q3. List the four broad classes of services that a transport protocol can provide. For each of the service classes, indicate if either UDP or TCP (or both) pro-vides such a service.
Q4. Why do HTTP, FTP, SMTP, and POP3 run on top of TCP rather than on UDP?
Q5. Skype uses P2P techniques for two important functions. What are they?