Vehicle-mounted system capable of making hands-free call

A vehicle-mounted system comprising:

• a vehicle-mounted apparatus that makes a hands-free call of a wireless apparatus possible;
• and
• a communication apparatus that connects the vehicle-mounted apparatus to a network, wherein
• the vehicle-mounted apparatus includes:
• a first communication interface that communicates with the wireless apparatus to communicate an audio signal for a hands-free call by connecting to the wireless apparatus and receives first data stored in the wireless apparatus from the wireless apparatus;
• a storage that stores the first data received by the first communication interface;
• and
• a second communication interface that communicates, via the communication apparatus, with a server connected to the network, wherein
• the second communication interface performs communication to synchronize second data that is stored in the server and that is backup data of the first data with the first data stored in the storage.