Which is the correct expression for the length of UDP datagram?
A. UDP length = IP length – IP header’s length
B. UDP length = UDP length – UDP header’s length
C. UDP length = IP length + IP header’s length
D. UDP length = UDP length + UDP header’s length
Answer:A
Which is the correct expression for the length of UDP datagram?
A. UDP length = IP length – IP header’s length B. UDP length = UDP length – UDP header’s length C. UDP length = IP length + IP header’s length D. UDP length = UDP length + UDP header’s length
Explanation: A user datagram is encapsulated in an IP datagram. There is a field in the IP header that defines the total length of the IP packet. There is another field in the IP header that defines the length of the header. So if we subtract the length of the IP header that is encapsulated in the IP packet, we get the length of UDP datagram.