Can anyone answer and explain the following questions from Into to Computer Networking course?

1)

PTSN networks are:

a) Packet-switching networks offering connection-oriented services

b) Packet-switching networks offering connectionless services

c) Circuit-switching networks offering connection-oriented services

d) Circuit-switching networks offering connectionless serive

2)

Connection setup and temination, if performed, takes places in this layer of the internet model

a) Presentation layer

b) Session layer

c) Network layer

d) Physical layer

3)

UDP sockets are identified by:

a) Client program port number

b) Server program port number

c) Destination IP and port addresses

d) Sourse and destination IP and port addresses

4)

HTTP is a stateless protocol. It can be made stateful by using:

a) Server programs that use TCP

b) Cookies

c) Web cache servers

d) DNS

5)

In recursive DNS queries:

a) Client DNS program contacts cashe DNS server after receiving a reply from root server

b) TLD server contacts authoritative server in behalf or requester

c) Burden is put on the requesting server

d) Root Server ensures that cache DNS server is always up-to-date

Thank you very much!