如何从iphone sdk中的callcenter返回的呼叫的callID（呼叫标识符）中获取电话号码？

I had tried to get the call status and call Identifier of a call using coreTelephony.framework.And Need to get the phone number of the incoming call.Is it possible to get the phone number using the CallID.If so can anyone suggest me with sample code.I had tried to get the call status and call Ide