iphone - iOS call status tracking and get phone number -

i making voicemail app ios. in app want 2 things-

1. call status - if called how status of i.e. busy or not reachable or switch off or call disconnected.

2. phone no - if status of call how can send voicemail on user phone. can user's phone no.

this not app app application. getting caller making him register through app mean can number of user called??? apple provide type of permission.

for first question:

• post1
• post2

for second question, there no way retrieve caller's phone number. coretelephony gives limited access information such unique identifier calls , call state. more information, you're going have use low-level functions , jailbreak means not accepted appstore.