Stateless vs Stateful

IP
TCP
HTTP

brower 	-> www.google.com
		-> DNS search for google.com return ip xxx.xxx.xxx.xxx
		-> connect to xxx.xxx.xxx.xxx
		-> GET / HTTP/1.0
		-> index.html with status code 200 ok


connect via http to xxx.xxx.xxx.xxx
	-> connect via tcp to xxx.xxx.xxx.xxx:80
		-> connect via ip to xxx.xxx.xxx.xxx

connect via https to xxx.xxx.xxx.xxx
	-> connect via tcp to xxx.xxx.xxx.xxx:443
		-> connect via ip to xxx.xxx.xxx.xxx

connect via ftp to xxx.xxx.xxx.xxx
	-> connect via tcp to xxx.xxx.xxx.xxx:21
		-> connect via ip to xxx.xxx.xxx.xxx


server -> socket create, bind, listen > accept-| 
client -> socket create, connect -----|        -- send/recv

Server A

1. create socket s
2. bind s with ip
3. listen on s for data from clients
4. client A ip:port
5. server creates socket t
6. connect t to client A ip:port
7. to send data to client A, use t
8. recieve data from client A on t
9. listen on s, gives connection from client B ip:port
10. server creates socket u
11. connect u to client B ip:port
12. to send data to client B, use u
13. recieve data from client B on u
14. close socket u
15. listen on s, gives connection from client B ip:port
16. server creates socket v
17. connect v to client B ip:port
18. to send data to client B, use v
19. recieve data from client B on v


client A 		server 
1  				1
1 				2
4 				6

client B 		server 
4  				4
2 				6
5 				11

4 				4
6 				10

1 				1, 0

2, 0 			3, 0