IT and Network experts..please help me in my assignment..tnx..?

Question

Short Answer Questions:
1. What is the broadcast address of the network 157.15.0.0 with a subnet mask of 255.255.0.0?
2. In class B network, the subnet mask is 255.255.252.0. The first network address is 143.62.8.0. What is the broadcast address of this subnet?
3. From question 2, what are the next subnet network address and its broadcast address?
4. From question 2, how many usable hosts for each subnet?
5. Why isn’t TCP suitable for real-time traffic?
6. Which function of Layer 6 protects data during transmission?
7. Which layer of the OSI model establishes, maintains, and manages sessions between applications?
8. What is the primary reason for using subnets?
9. How are collisions avoided using a token-passing scheme?
10. At which layer of the OSI model are FTP and TFTP located?
11. What are the advantages of connectionless over connection-oriented?
12. What type of address UDP needs to deliver the user datagram to the correct application program?

13. What is the purpose of a firewall and in which layer does it function?
14. Given EA = A’s public key, DA = A’s private key, P = plaintext,
EB = B’s public key, DB = B’s private key
For cipher text, C = EA(DB(P)), what function of key is needed to decrypt this message?
15. From question 14, this cipher text, C = EA(DB(P)) was sent by whom? (A or B?) Give reason(s) to support your answer.

note: in question 14 and 15...EA should be read as E sub A..A and B are subscripts

Answer 1

If you would have paid a little closer attention in class or have read the text then you wouldn't want us that have been there and done that to do your HOMEWORK
Don

Answer 2

I would recommend doing your own homework if you are really interested in learning this stuff.