Quote Originally Posted by naresh
sending (writing to socket) took 2 seconds at server (file 1810,6 kB) and client was receiving it 11 seconds
Most likely it was because of some buffering at OS level.

Quote Originally Posted by naresh
How to make sure that client received data to socket?
You will never know. Unless it sends you an confirmation, but then again the client won't know if you got it, so you will have to send a confirmation of that confirmation, which brings you to the starting point.