(1) Calculate the checksum for the following UDP header:

source port: 8080

Destination port: 32001

Length: 50010

Assume only these three fields.

(2) Why UDP use 1's complement instead of just the sum?

(3) How does the receiver know there is an error from the checksum? And if receiver receive 50011 instead of 50010 for the packet length. How is the error detected?

(4) Give an example which error will go undetected, and explain it? How many bits are different?