Chances are it is your modem/router.
I get pretty much exactly the same ping/down and up as you and i'm fine.
I woudl actually try turning your modem off for 30mins. And while it is off, unplug all of your landlines (home phones) Then switch the modem back on and go and run and xbox live connection test.
Then after that get into a CoD match and see what it is like.
If it is good then connect your landline (homephones) together one at a time (if you have more than one) making sure to test what your connection does on CoD before you connect the next.
If everything is steady after that then oila.
But....
It seems like you may need a new modem.
Other than that try downloading stuff and make sure it downloads at the speed the the speed test says which is in your circumstance should be about 700kb/s.
If not ring your IP and tell them the problem. What i could also probably be is you are experienceing much packet loss between your IP and the hosts IP which is also a sign of a faulty landline or modem.
Posted on Tuesday, 31st January 2012