3- (4 points) Answer the following questions based on the format of a TCP packet:

a) How many bits are reserved for control information?

b) How many bits is reserved for source address?

c) How many bits is reserved for destination address?

d) How many bits is reserved for payload?

4- (6 points) Fill in the blanks:

a) __________ is based on travelling datagrams through internetworks one hop at a time. The entire route is unknown at the beginning of the journey.

b) ___________ is group-based communication. It can be one-to-many or many-to-many distribution.

c) The most important requirement of a ________ network is the ability to treat different data types differently.

d) _____________ process transmits telephone calls (voice) over the internet.

e) _____________ is the standard recommended by the ITU for low bit-rate voice transmission over the Internet.

f) _____________ is an unencrypted message data.

7- (5 points) Suppose you want to create password using lowercase (a~z) and uppercase (A~Z) English alphabet characters, as well as numbers 0~9. How many possible passwords can be generated if the length of the password is 5?