Q: Face time comes up with error "can not connect to network"

Look at iOS Troubleshooting Wi-Fi networks and connections  http://support.apple.com/kb/TS1398

Also try this - Turn Off your iPad. Then turn Off the wireless router & then back On. Now boot your iPad. Hopefully it will see the WiFi.

 Cheers, Tom 

I have this same problem and have checked all settings to no avail.  Facetime and imessage do work on my ipod using the same wifi and settings. Still can't activate facetime on the ipad2.

Have the same problem with my iphone! What can we do

See here -

Troubleshooting Messages

http://support.apple.com/kb/TS2755

Troubleshooting FaceTime

http://support.apple.com/kb/HT4319