How are numbers being converted during the transfer process?

On their way from the Smartphone to the Gigaset handset the numbers will run through several transformation units (APP, base station, handset). The APP cleans the numbers from blanks, strokes etc.. The base station converts numbers from international style (e.g. +49...) to national style (0...) and splits mobile contacts with multi numbers into separate contacts with one number, depending on the handset capabilities to handle contacts in its directory. The handset removes the local area code, if it was entered be the customer.