What makes UDP into a proper transport protocol?

Select one:

a. it uses the services of the network layer

b. it supports IPv4 and IPv6 addressing

c. its port numbers

d. the checksum field

e. it supports large sends

From the TCP ESTABLISHED connection state, what is the next state after the application closes (active close)?

Select one:

a. CLOSED

b. CLOSING

c. CLOSE WAIT

d. FIN WAIT 2

e. FIN WAIT 1

Which field of the IPv4 packet header contains a value to identify the contents of the packet body?

Select one:

a. the Contents field

b. the Padding field

c. the Protocol field

d. the Options field

e. the Identification field