Problem 1:
(a) Briefly describe the concept of peer-to-peer communication in the context of Layered Protocol Architecture. How is virtual communication achieved between peer layers? For which layers do we have virtual/logical communication links in the Internet Protocol Stack?
(b) Briefly describe and compare the DNS and Gnutella protocols, in particular, how to access/obtain desired information/data/files as specified by the respective protocols
(c) Describe how web caching can reduce the delay in receiving a requested object. Will web caching reduce the delay for all objects requested by a user or for only some of the objects? Why
(d) How are ports numbers used by TCP and/or UDP in demultiplexing incoming segments?
Problem 2: Please choose the correct answers for the following statements.
1. SMTP is used to download mail from a mail server to a local host. (T/F)
2. UDP provides a guarantee of delivery. (T/F)
3. One DNS record might appear in multiple DNS servers. (T/F)
4. Losing a segment does not cause the timeout value to change in TCP. (T/F)