1 | initial version |
In general , if client send syn, the server will return an ack, and server will set a expired time named "RTO", which means "retranmission time out";if client ack didnt arrive in time , it will trigger "tcp retranmission " ; if client ack didnt arrive in time again, send "tcp retranmission " again and set "RTO" to double or incrase in power; In the end , the server will think client has lost , so server will send "Reset " to client and tell client to release this connection; Most devices use this way to connect and release, but if there is a firewall , then the case is different