#UDPPingerServer.py
#We will need the following module to generate randomized lost packets

import random
from socket import socket, AF_INET, SOCK_DGRAM

#Create a UDP socket 
#Notice the use of 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)
serverSocket.close()