Batttlefield 3 ps3 issue

[#1]

Hi
I just got BF3 and i keep dropping out of servers with a lost connection error although i stay signed in.
Could this be an issue with the plusnet router.  I have the thompson gateway one which they curretly supply (i have only been with them for 3 months).
Is there anying i can do are there any settings i can change.  I looked online and saw about a DMZ however i cant work out how to do this with the router as it has no dmz option.
Sometimes the drops are causing the game to lock up.
I have issus wih a slow upload speed normally max 170k not sure if this could be an issue.  I have no idea why its low, it has caused  issus with facetime connectng.

[#2]

I had one complete system lock-up when I first went on Multi-player and had to reboot the PS3 but tried again and it played fine (unlike me).
I'm using a Billion 7800N.

[#3]

I get dropped out of a server every 10mis or so.