The client does not send data to the server

STM32F4 use as a client, the server runs on a PC Windows. After starting the client connection is successful, the program server receives a message for a new connection, but the client code starts to send data, the data array 1024 KB connection is broken.
The server program written in Qt and checked on the client running on another PC. The client program uses the driver from the manufacturer of the chip.
I can not find an example of a simple TCP connections with static addresses. Help start the data transfer.