TCP keep-alive mode when it goes into?

I want to send big image data from linux box to windows client..

From Linux server socket , it just send

while ( end of file )
{
write ( clientfd ... )
}

On the client , it just receive...

while ( read (socketfd , , ) ) ;


Normally, it send whole data to windows clients...
but , it sometimes , it entered to KEEP-ALIVE mode even though it is
not end of image data ..
and stop its sending... just keep only TCP connection..


I don't know why it goes into KEPP-ALIVE mode?
When I capture TCP packet , I can see follwings...


No Time source Desti Protocol Info
6514 27.04555 x y TCP [TCP Keep-Alive]
5001 > 4656 [ACK] seq=5560059 ACk=0 Win=5840


Have a nice day.

google-rambo88 wrote:
> I want to send big image data from linux box to windows client..
>
> From Linux server socket , it just send
>
> while ( end of file )
> {
> write ( clientfd ... )
> }
>
> On the client , it just receive...
>
> while ( read (socketfd , , ) ) ;

You cannot assume that read() and write() respectively read and write
the complete byte count that you specify for a TCP socket; you have to
monitor the return values.

Robert

> [snip]