TPAAnalog

How to run:

• You need to run "networkLayer", using defined arguments:

  python networkLayer.py port maxNoPackets delay probDrop probMangle
  

• Then Server.java which by default listen to port 5001. To run the server on a different port pass it as an argument:

  javac Server.java 5001
  

• Client.java runs as the last file using three arguments for host, port and filename to read:

  javac Client.java localhost 5002 test.txt
  

How Packets are structured:

• After reading the file, we are generating a Stack of Strings with this special padding:
  • All strings have a length of 512 characters.
  • The first 36 characters is a unique Java UUID which is used as a packet signature.
  • The next 3 characters determine the number of packets we are sending to the server. We use this to assert if we have sent all the unique packets from client to server.
  • The rest of String (473 characters) are filled with the data we have read from the file.
  • If we have some characters at the end of our file (less than 473 characters), we add enough characters to the end of it so we have another full packet.
  • We keep each packet as an string and push them into a Stack.
  
  
  

TCP 3-Way Handshake:

• Client Side:

  • We push all the packets into a Stakc<String>.
  • Everytime, client sends one packet (from the top of our Stack) to Server as its SYN, then it chooses its next move based on the Server Response:
    • If Server SYNACK is a packet with less than 512 characters, client considers that as a "Corrupt Response", and it sends the packet again.
    • If client got a valie SYNACK from server, client will send the first 36 characters as ACK message.
      • Since client has sent this message successfully, the message will be moved to the bottom of Stack. Note that since the ACK message could fail itself, we should not remove the message from the Stack.
    • If client received a END message, it means the Server has got all the messages correctly, so client will return.

• Server Side:

  • Once server gets a SYN message from the client, it checks the basic packet structure in order to find out if it's a valid Packet.
    • A packet considered as Valid SYN if it has the correct number of characters (512) for each part of its structure and a valid UUID.
  • If server gets a valid Packet, it stores the packet in a temporary HashMap<UUID, PACKET> and sends a SYNACK to the client.
  • Once server gets a ACK message from the client, it checks UUID to make sure it has been stroed in its temporary HashMap and then stores the Data part of the packet in a HashSet, since the order of packets doesn't matter but they need to be unique (use a LinkedHashSet if order matters).
    • A message considered as Valid ACK if it has correct number of characters (36) and there is a key in our HashMap keeping its related Packet.
  • In every turn, server checks to see if it has all the packets. If it does, Server will repeatedly send a closing message END to client.
    • Note that number of packets is being sent as one part of our packet.

Sample basic output

• using attached text.txt file and 5002 100 1 0 0 as networkLayer argument, localhost 5002 test.txt as Client.java argument and 5001 as Server.java argument:

Server:

Server is listening ...
Number of Packets: 8
ACK is transmitted for guid#: 2949ee60-8883-49b1-a361-4314492d8e39
ACK is transmitted for guid#: 2949ee60-8883-49b1-a361-4314492d8e39
ACK is transmitted for guid#: 2949ee60-8883-49b1-a361-4314492d8e39
ACK is transmitted for guid#: 2949ee60-8883-49b1-a361-4314492d8e39
Msg for GUID# 2949e has been stored on server successfully!
ACK is transmitted for guid#: eb02d25b-ac5b-4b68-b70b-6d63ec6fcbea
ACK is transmitted for guid#: f4e9bcba-50e0-4738-b8d6-4833e5381689
ACK is transmitted for guid#: cde1d50a-9ee5-43d7-a9be-68e8771245a4
Msg for GUID# eb02d has been stored on server successfully!
ACK is transmitted for guid#: 3118b957-ee24-450f-b9f7-b07eab664d60
Msg for GUID# f4e9b has been stored on server successfully!
ACK is transmitted for guid#: fa7ff776-0f10-440b-90f9-0737185525b1
Msg for GUID# cde1d has been stored on server successfully!
ACK is transmitted for guid#: 1b54789d-df24-4a6d-a1b5-240f0327ffd2
Msg for GUID# 3118b has been stored on server successfully!
ACK is transmitted for guid#: a04a248a-6834-468e-8450-6c4a39cf2488
Msg for GUID# fa7ff has been stored on server successfully!
ACK is transmitted for guid#: 2949ee60-8883-49b1-a361-4314492d8e39
Msg for GUID# 1b547 has been stored on server successfully!
ACK is transmitted for guid#: eb02d25b-ac5b-4b68-b70b-6d63ec6fcbea
Msg for GUID# a04a2 has been stored on server successfully!
ACK is transmitted for guid#: f4e9bcba-50e0-4738-b8d6-4833e5381689
Msg for GUID# 2949e has been stored on server successfully!
ACK is transmitted for guid#: cde1d50a-9ee5-43d7-a9be-68e8771245a4
Msg for GUID# eb02d has been stored on server successfully!

Client:

Timeout! Retransmitting...
Got a Valid Message by Server: 2949e
	 send back the acknowledgement for quid: 2949e
Got a Valid Message by Server: 2949e
	 send back the acknowledgement for quid: 2949e
Got a Valid Message by Server: 2949e
	 send back the acknowledgement for quid: 2949e
Got a Valid Message by Server: eb02d
	 send back the acknowledgement for quid: eb02d
Got a Valid Message by Server: f4e9b
	 send back the acknowledgement for quid: f4e9b
Got a Valid Message by Server: cde1d
	 send back the acknowledgement for quid: cde1d
Got a Valid Message by Server: 3118b
	 send back the acknowledgement for quid: 3118b
Got a Valid Message by Server: fa7ff
	 send back the acknowledgement for quid: fa7ff
Got a Valid Message by Server: 1b547
	 send back the acknowledgement for quid: 1b547
Got a Valid Message by Server: a04a2
	 send back the acknowledgement for quid: a04a2
Got a Valid Message by Server: 2949e
	 send back the acknowledgement for quid: 2949e
Got a Valid Message by Server: eb02d
	 send back the acknowledgement for quid: eb02d
---------------------------
SERVER GOT ALL THE MESSAGES
---------------------------

Output with Mangled/Dropped packets:

• using attached text.txt file and 5002 100 1 5 5 as networkLayer argument, localhost 5002 test.txt as Client.java argument and 5001 as Server.java argument:

Server:

Server is listening ...
Number of Packets: 8
ACK is transmitted for guid#: 370a051b-2473-4631-ac3e-9ffb69a42da5
ACK is transmitted for guid#: 370a051b-2473-4631-ac3e-9ffb69a42da5
Server has received a corrupted msg! : 513
ACK is transmitted for guid#: 370a051b-2473-4631-ac3e-9ffb69a42da5
ACK is transmitted for guid#: 370a051b-2473-4631-ac3e-9ffb69a42da5
ACK is transmitted for guid#: 370a051b-2473-4631-ac3e-9ffb69a42da5
Msg for GUID# 370a0 has been stored on server successfully!
ACK is transmitted for guid#: ef91747f-5278-4ea7-8278-cb987f71e18e
ACK is transmitted for guid#: 80cbf33d-7094-4e93-88c0-e45e3f4a4653
ACK is transmitted for guid#: 442bc9cd-d481-4345-90dd-d86b1aeff2fc
Msg for GUID# ef917 has been stored on server successfully!
ACK is transmitted for guid#: 95ca0423-c9f4-4aba-b43d-a035b447c75c
Msg for GUID# 80cbf has been stored on server successfully!
ACK is transmitted for guid#: 0cd93aba-481e-4233-afb3-b6f44ef26704
Server has received a corrupted msg! : 513
ACK is transmitted for guid#: 0cd93aba-481e-4233-afb3-b6f44ef26704
ACK is transmitted for guid#: 0cd93aba-481e-4233-afb3-b6f44ef26704
ACK is transmitted for guid#: 0cd93aba-481e-4233-afb3-b6f44ef26704
Msg for GUID# 0cd93 has been stored on server successfully!
ACK is transmitted for guid#: 58b17d86-8a87-4bf2-854b-da524e9fcdb9
ACK is transmitted for guid#: 58b17d86-8a87-4bf2-854b-da524e9fcdb9
ACK is transmitted for guid#: 58b17d86-8a87-4bf2-854b-da524e9fcdb9
Msg for GUID# 58b17 has been stored on server successfully!
ACK is transmitted for guid#: 1f24e60b-a004-4122-8a65-56e3c75e0966
ACK is transmitted for guid#: 370a051b-2473-4631-ac3e-9ffb69a42da5
ACK is transmitted for guid#: ef91747f-5278-4ea7-8278-cb987f71e18e
Msg for GUID# 1f24e has been stored on server successfully!
ACK is transmitted for guid#: 80cbf33d-7094-4e93-88c0-e45e3f4a4653
Msg for GUID# 370a0 has been stored on server successfully!
ACK is transmitted for guid#: 442bc9cd-d481-4345-90dd-d86b1aeff2fc
Msg for GUID# ef917 has been stored on server successfully!
ACK is transmitted for guid#: 95ca0423-c9f4-4aba-b43d-a035b447c75c
Guid is mangled by server : 0)d 3aba-481e-4233-afb3-b6f44ef26704
Msg for GUID# 442bc has been stored on server successfully!
ACK is transmitted for guid#: 58b17d86-8a87-4bf2-854b-da524e9fcdb9
ACK is transmitted for guid#: 58b17d86-8a87-4bf2-854b-da524e9fcdb9
ACK is transmitted for guid#: 58b17d86-8a87-4bf2-854b-da524e9fcdb9
Msg for GUID# 58b17 has been stored on server successfully!
ACK is transmitted for guid#: 1f24e60b-a004-4122-8a65-56e3c75e0966
ACK is transmitted for guid#: 370a051b-2473-4631-ac3e-9ffb69a42da5
Server has received a corrupted msg! : 550
ACK is transmitted for guid#: 80cbf33d-7094-4e93-88c0-e45e3f4a4653
ACK is transmitted for guid#: 80cbf33d-7094-4e93-88c0-e45e3f4a4653
Server has received a corrupted msg! : 550
ACK is transmitted for guid#: 442bc9cd-d481-4345-90dd-d86b1aeff2fc
ACK is transmitted for guid#: 442bc9cd-d481-4345-90dd-d86b1aeff2fc
ACK is transmitted for guid#: 442bc9cd-d481-4345-90dd-d86b1aeff2fc
Msg for GUID# 442bc has been stored on server successfully!
ACK is transmitted for guid#: 95ca0423-c9f4-4aba-b43d-a035b447c75c
ACK is transmitted for guid#: 0cd93aba-481e-4233-afb3-b6f44ef26704
ACK is transmitted for guid#: 58b17d86-8a87-4bf2-854b-da524e9fcdb9
Msg for GUID# 95ca0 has been stored on server successfully!
ACK is transmitted for guid#: 1f24e60b-a004-4122-8a65-56e3c75e0966
Msg for GUID# 0cd93 has been stored on server successfully!
ACK is transmitted for guid#: 370a051b-2473-4631-ac3e-9ffb69a42da5
Msg for GUID# 58b17 has been stored on server successfully!
Server has received a corrupted msg! : 53

Client:

Timeout! Retransmitting...
Timeout! Retransmitting...
Timeout! Retransmitting...
Timeout! Retransmitting...
Got a corrupt ACK from Server - len: 1
Got a Valid Message by Server: 370a0
	 send back the acknowledgement for quid: 370a0
Got a Valid Message by Server: 370a0
	 send back the acknowledgement for quid: 370a0
Got a Valid Message by Server: 370a0
	 send back the acknowledgement for quid: 370a0
Got a Valid Message by Server: ef917
	 send back the acknowledgement for quid: ef917
Got a Valid Message by Server: 80cbf
	 send back the acknowledgement for quid: 80cbf
Timeout! Retransmitting...
Got a corrupt ACK from Server - len: 8
Timeout! Retransmitting...
Timeout! Retransmitting...
Got a corrupt ACK from Server - len: 9
Got a Valid Message by Server: 0cd93
	 send back the acknowledgement for quid: 0cd93
Timeout! Retransmitting...
Got a corrupt ACK from Server - len: 12
Got a Valid Message by Server: 58b17
	 send back the acknowledgement for quid: 58b17
Got a Valid Message by Server: 58b17
	 send back the acknowledgement for quid: 58b17
Got a Valid Message by Server: 58b17
	 send back the acknowledgement for quid: 58b17
Got a Valid Message by Server: 1f24e
	 send back the acknowledgement for quid: 1f24e
Got a Valid Message by Server: 370a0
	 send back the acknowledgement for quid: 370a0
Got a Valid Message by Server: ef917
	 send back the acknowledgement for quid: ef917
Got a Valid Message by Server: 80cbf
	 send back the acknowledgement for quid: 80cbf
Got a Valid Message by Server: 442bc
	 send back the acknowledgement for quid: 442bc
Timeout! Retransmitting...
Got a corrupt ACK from Server - len: 21
Got a Valid Message by Server: 58b17
	 send back the acknowledgement for quid: 58b17
Got a Valid Message by Server: 58b17
	 send back the acknowledgement for quid: 58b17
Got a Valid Message by Server: 58b17
	 send back the acknowledgement for quid: 58b17
Got a Valid Message by Server: 1f24e
	 send back the acknowledgement for quid: 1f24e
Timeout! Retransmitting...
Timeout! Retransmitting...
Got a corrupt ACK from Server - len: 26
Got a Valid Message by Server: 80cbf
	 send back the acknowledgement for quid: 80cbf
Timeout! Retransmitting...
Timeout! Retransmitting...
Got a corrupt ACK from Server - len: 28
Got a Valid Message by Server: 442bc
	 send back the acknowledgement for quid: 442bc
Got a Valid Message by Server: 442bc
	 send back the acknowledgement for quid: 442bc
Got a Valid Message by Server: 442bc
	 send back the acknowledgement for quid: 442bc
Got a Valid Message by Server: 95ca0
	 send back the acknowledgement for quid: 95ca0
Got a Valid Message by Server: 0cd93
	 send back the acknowledgement for quid: 0cd93
Got a Valid Message by Server: 58b17
	 send back the acknowledgement for quid: 58b17
---------------------------
SERVER GOT ALL THE MESSAGES
---------------------------