Fanuc oi-mf Plus DNC over ethernet issue

Hey Guys,
I just started using a Romi D1000 with the oi-mf plus controller. Ftp file transfer working, i can copy programs from my pc to the controller. I making custom parts with cam, so many times a day i need to transfer program to the controller, so it would be good if i can run programs directly from the ftp server. DNC works for a while, but after some 2-3k lines of program transferred the controller disconnects from the server, and around 5k line the data runs out, E-0215 inputting a file failed from host (10054) error appears. Strange thing is that when i start DNC, the ftp server log shows that the entire program transferred, then it keeps alive the connection until 2-3k lines are transferred, then controller disconnects from the server. Looks like the issue is not timeout related, when i turn down the feed or even stops it roughly the same amount of data are transferred (but never exactly the same amount). I think, that i need somehow keep alive the ftp connection, but from server side i cannot doing this. I am using filezilla, but tryed 3 more ftp server already with the same result.
Any help would be much appreciated.

I forget to write, that short programs (max 2k lines) runs flawlessly with DNC.

ola, você ja resolveu seu problema? eu fiquei três meses a procura de uma solução até que a fanuc me passou um procedimento que resolveu meu problema de transmisão. Caso você precise me fale, eu tento enviar o pdf.
O meu problema era exatamente igual ao seu, esse problema é um problema de fabrica.