+---------+ ---------\      active OPEN  
                            |  CLOSED |            \    -----------  
                            +---------+<---------\   \   create TCB  
                              |     ^              \   \  snd SYN    
                 passive OPEN |     |   CLOSE        \   \           
                 ------------ |     | ----------       \   \         
                  create TCB  |     | delete TCB         \   \       
                              V     |                      \   \     
          rcv RST (note 1)  +---------+            CLOSE    |    \   
       -------------------->|  LISTEN |          ---------- |     |  
      /                     +---------+          delete TCB |     |  
     /           rcv SYN      |     |     SEND              |     |  
    /           -----------   |     |    -------            |     V  
+--------+      snd SYN,ACK  /       \   snd SYN          +--------+
|        |<-----------------           ------------------>|        |
|  SYN   |                    rcv SYN                     |  SYN   |
|  RCVD  |<-----------------------------------------------|  SENT  |
|        |                  snd SYN,ACK                   |        |
|        |------------------           -------------------|        |
+--------+   rcv ACK of SYN  \       /  rcv SYN,ACK       +--------+
   |         --------------   |     |   -----------                  
   |                x         |     |     snd ACK                    
   |                          V     V                                
   |  CLOSE                 +---------+                              
   | -------                |  ESTAB  |                              
   | snd FIN                +---------+                              
   |                 CLOSE    |     |    rcv FIN                     
   V                -------   |     |    -------                     
+---------+         snd FIN  /       \   snd ACK         +---------+
|  FIN    |<----------------          ------------------>|  CLOSE  |
| WAIT-1  |------------------                            |   WAIT  |
+---------+          rcv FIN  \                          +---------+
  | rcv ACK of FIN   -------   |                          CLOSE  |  
  | --------------   snd ACK   |                         ------- |  
  V        x                   V                         snd FIN V  
+---------+               +---------+                    +---------+
|FINWAIT-2|               | CLOSING |                    | LAST-ACK|
+---------+               +---------+                    +---------+
  |              rcv ACK of FIN |                 rcv ACK of FIN |  
  |  rcv FIN     -------------- |    Timeout=2MSL -------------- |  
  |  -------            x       V    ------------        x       V  
   \ snd ACK              +---------+delete TCB          +---------+
     -------------------->|TIME-WAIT|------------------->| CLOSED  |
                          +---------+                    +---------+