Create a Person
entity with a to-many
(or to-one if there is only one phone #) relationship to a Phone
entity.
The Phone
entity will have a to-one relationship to a Person
entity.
In addition it will have the inner structure you described (country_code,area_code,number).
You don't need an id
property in order to create a CoreData entity.
You could set the relationship to 'cascade', so that when a person is deleted all related phone numbers are deleted.
When you traverse you JSON response, read the "phone" key into a Phone
entity and the its person
property to the person you are currently traversing.