UDPPingerServer.py

# This is the UDP server program.
# This sends the capitalized message to the client.
# This works on the value od rand.
# If rand is less than 4 then the response is not sent
# If rand is greater than or equal to 4 then the response is sent.

import random
from socket import *

# Create a UDP socket
# We should use SOCK_DGRAM for UDP packets
serverSocket = socket(AF_INET, SOCK_DGRAM)

# Assign IP address and port number to socket
serverSocket.bind(('', 12000))

while True:

	# Generate random number in the range of 0 to 10
	rand = random.randint(0, 10)

	# Receive the client packet along with the address it is coming from
	message, address = serverSocket.recvfrom(1024)

	# Capitalize the message from the client
	message = message.upper()

	# If rand is less is than 4, we consider the packet lost and do not respond
	if rand < 4:
		continue

	# Otherwise, the server responds
	serverSocket.sendto(message, address)