Alice is at a computer behind a NAT gateway that has the private IP address 10.23.44.55. The gateway has the first IP address in the range; she has the fiftyfifth. She opens a connection to a file...

Alice is at a computer behind a NAT gateway that has the private IP address 10.23.44.55. The gateway has the first IP address in the range; she has the fiftyfifth. She opens a connection to a file transfer server at 74.125.224.80.

a. Choose a five-digit source port number to be used by Alice’s protocol stack.

b. Given the port number chosen for Alice’s protocol stack above, give the full socket address as seen on the private side of the gateway. The destination port is the customary port for setting up a file transfer, as given in Section 11.3.

c. Choose another five-digit port number to be assigned by the NAT to this connection.

d. Assume that the NAT gateway has a global IP address of 11.22.33.44. Using the NAT port number chosen above, give the full socket address as seen on the Internet side of the gateway.