1. What is the difference between network architecture and application architecture?

2. What is meant by the handshaking protocol?

3. What information is used by a process running on one host to identify a process running on another process?

4 Consider DNS protocol. (8 points)

a. Sketch the main architecture of domain name servers currently used for the Internet. You should include a client, a server and different types of DNSs.

b. Explain four different types of record which are kept in a DNS list.

c. Name two different types of a DNS query. Complete your sketch with some arrows to explain how these two approaches work.

d. What is the necessity of having Root Domain Name Server?

5.Describe how web caching can reduced the delay in receiving a requested object .Will web caching reduce the delay for all objects requested for all objects or just some objects?

6. Is it possible for an organizations web server and mail server to have exactly the same alias for hostname name? What would be the type of RR that contains hostname of the mail server?

7. Consider distributing a file of F = 15Gbits to

N peers. The server has an upload rate of u_s = 30Mbps, and each peer has a download rate of d_i = 2Mbps and an upload rate of u.

(a) (2 points) For N = 100 and u = 700Kbps, find the minimum distribution time for client- server distribution.

(b) (2 points) For N = 100 and u = 700Kbps, find the minimum distribution time for client- server distribution, find the minimum distribution time for P2P distribution.

c) (2 points) Suppose the number of peers increases to N = 1000, find the minimum distri bution time for both client-server and P2P distribution.