Broadband Christchurch

Call of Duty 4 is a great game when I got online and played it was late, but very little, but when I played today was very lag (please excuse the swear ) f *** ing, s *** ty boring and i struggled through a door in multiplayer online!
It takes like 5 seconds to plant a claymore, C4, grenades, and when I want to go a certain way it makes me do random directions.
I did a speed test and my download is about 6 MB download is about 800 KB.
Call of Duty 4 is a great game I do not want to break my PS3 or rage.
I live in Christchurch, New Zealand and use broadband Telecom
I use the modem D-Link Belkin F5D7230 502-t-4 and the router.
I forwarded the port.

So can someone please help me!a

I had a Belkin router before too horrible connection, you need to upgrade that router to a Netgear - "N2" router, do not get the "G" router because it wont help and its the most basic router. You must be at least "N" or "N2" works perfectly for me and I have two PS3 can play together without any problems.

...

dude get a 2wire AT & T their ******* awesome no lag! Oh, and the solution to your problems is that you need for a new Internet connection or verify your PS3 xD