Steve Litchfield of AllAboutSymbian has done a complete online test to check open ports on a S60 device and find out if it is necessary to have a security firewall on your S60 smartphone.

The test was taken on the latest version of Shields Up! in which a Nokia 6630 running S60, 2nd Edition achieved a perfect score, with all 1056 tested TCP/IP ports resisting all attempts at unwanted communication from the outside world. He even tried a Nokia 9500 over Wireless-LAN, on the same Shields Up! test so as to exclude any network carrier based firewall.

The result is: S60 does NOT need a firewall.

AllAboutSymbian