First of all sorry for my English. I hope you guys understand my problem

I have a 655 A3 v. 121 EU.... I use t have a Synology server with ftp and a file server allways activate for my friends to download movies, etc.
The problem is that when I try to play on-line with my ps3 (wired) I have too much lag and is imposible to play well.
I have DCHP activated. And qos service activate for default priority, Im trying to use qos manually and I tried with the IP of the ps3 seted in 1 and the Synology server in 255 but it doesnt makes it work better.
In the Internet log I can see that the priority is well. "1" for the PS3 and "255" for the Synoloy... But in the other hand works like the Synology uploads consume all the bandwidht, maybe the Synology pryority makes the transference begin after but consumes all the bandwidth.
Any solution?? I would like to limit the Synology bandwidth by port or by IP because the qos doesnt work well for me... Is that possible? Any suggestion???
Thanks in advance mates!!!