Apple iPhone 6 Plus
Apple iPhone - Update Carrier Settings
Apple® iPhone® - Update Carrier Settings
Carrier settings updates are small files that are installed on iOS devices; having the most up to date carrier settings is recommended for proper functionality of your device.
Carrier settings include updates to Access Point Names (APNs), Multimedia Messaging Service (MMS) settings, features such as tethering or default apps such as Stocks, Maps, and Weather.
For more info, refer to
iOS: Updating Your Carrier Settings
From the Home screen, navigate:
If a carrier settings update is available, you're presented with an option to update.