Official: Tiscali aren't blocking Call of Duty on purpose
The fact is, many ISPs block or 'throttle' certain types of traffic at certain times of the day due to network strain issues. If they didn't then the majority of customers would suffer as a result of activities carried out by the minority.
The ports and type of traffic Call of Duty 4 uses would appear to be similar to the kind of P2P traffic generated when downloading files via BitTorrent, and so Tiscali (like other ISPs) limit this kind of traffic for the good of the majority of their clients.
Certainly there is one thing that is true - Tiscali are not blocking CoD4 players on purpose. We asked Tiscali to put the record straight:
"Reports suggesting that we were deliberately blocking specific games areWe'll keep you up-to-date on the results of these 'routine updates' but I would suspect that this issue will go away soon for Tiscali PS3 gamers.
incorrect. We are constantly working to upgrade and refine our network to ensure
our customers can enjoy their favourite applications. Work is currently underway
on routine updates and we will keep you informed." - Tiscali UK