I was wondering what happens when the same number calls over and over on a samsung S2?

[AC Question]

Just wondering if it's a feature on the phone or if the person actually turned the phone off after so many calls. Every phone call, it rings but after calling so many times it goes straight to voicemail. Then a few minutes later it goes back to ringing. Is this a feature on the phone or is this because the person has turned off their phone?