You can try resetting your iPad by simultaneously pressing and holding the Home and Sleep/Wake buttons until you see the Apple Logo. This can take up to 15 seconds so be patient and don't release the buttons until the logo appears. Try again to see if the problem persists.
If yes, sign out of Facetime, then sign back in to see if anything changes.
Thanks, but no luck. The same problem is actually also occurring with my iMessage. Used to work, but now when I go into settings and enter username and password to activate iMessage, it doesn't recognize me and says to check network connection. Very puzzled. Location services are on and time and date are set to auto.
Using FaceTime http://support.apple.com/kb/ht4319
Troubleshooting FaceTime http://support.apple.com/kb/TS3367
The Complete Guide to FaceTime + iMessage: Setup, Use, and Troubleshooting
Troubleshooting FaceTime and iMessage activation
iOS: FaceTime is 'Unable to verify email because it is in use'
Using FaceTime and iMessage behind a firewall
iOS: About Messages
Set up iMessage
iOS 6 and OS X Mountain Lion: Link your phone number and Apple ID for use with FaceTime and iMessage
How to Set Up & Use iMessage on iPhone, iPad, & iPod touch with iOS
Extra FaceTime IDs
Troubleshooting iMessage Issues: Some Useful Tips You Should Try
Setting Up Multiple iOS Devices for iMessage and Facetime
FaceTime and iMessage not accepting Apple ID password
Fix Can’t Sign Into FaceTime or iMessage iOS 7
FaceTime, Game Center, Messages: Troubleshooting sign in issues
Unable to use FaceTime and iMessage with my apple ID
How to Block Someone on FaceTime
My Facetime Doesn't Ring
Send an iMessage as a Text Message Instead with a Quick Tap & Hold
To send messages to non-Apple devices, check out the TextFree app https://itunes.apple.com/us/app/text-free-textfree-sms-real/id399355755?mt=8
How to Send SMS from iPad
You can check the status of the FaceTime/iMessage servers at this link.
Hi there! I also had this problem awhile ago... And it really freakin' ****** me off! I reseacrh on net what could be the possible solution because the one here on apple page doesnt work! Thanks to Rene Ritchie from www.imore.com, his blog really helps a lot. Try and check if it will also work for you... ------>http://www.imore.com/having-trouble-imessage-or-facetime-ios-7-heres-how-fix-it
Hope this helps! Goodluck