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
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
Unable to use FaceTime and iMessage with my apple ID
How to Block Someone on FaceTime
My Facetime Doesn't Ring
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.
I'm having the same problem and it is a new bug introduced with iOS7. The links you provided are generic trouble shooting links. Everything was fine until the update. There is nothing wrong with my network because facetime and messages still work fine on my iPod running iOS6. My Apple ID is valid and works everywhere else except facetime and messages app on my iPad after I upgraded to iOS7.
My hardware is out of warranty so there is no way I am paying to get support on this issue. There are MANY complaints about this issue since iOS7 has been released and the most helpful suggestion I have seen is to reset and restore the device -then it works. I can't do that because there is an issue that has prevented my iPad from completing a backup for almost a year. Another suggestion I have seen is to create a NEW apple ID to use with facetime and messages. That isn't going to happen because I should not have to jump through hoops because apple dropped the ball. I have gone into the device settings and reset the network settings but this didn't solve the problem.
Unless they can correct this with an update to iOS7 my iPad lost quite a bit of functionality. I'm really not happy about this situation.
Eureka!! I have found someone with a smart, simple and efficient solution that actually works without all the hoopla (hard reboot/reset network settings/restore) suggested in this thread!
I have an iPhone 4 with iOS 7.0.3 and I went through those steps:
- Go to "Settings">Scroll down to "iTunes Store & App Store">Logout from the account
- Turn off your device, wait 1 minute or 2 then turn your device back on
- Return to "Settings">Scroll down to "iTunes Store & App Store">Login (can take up to a minute)
- And voilà! iMessage and FaceTime are back in business!
Note: it works without any need for a restoration.
This fixes as well all the problems in Google/Facebook/WhatsApp/etc. that require you to "Connect to iTunes to activate push notifications".
Thanks a lot to our fellow Apple Forumer Hunter Guerrero (see his valuable post here: https://discussions.apple.com/thread/5318138?start=75&tstart=0).