You can change the settings of various phone services.
Call services may include call forwarding, call waiting, voicemail, and more.
Contact your mobile operator to find out about the availability of call services.
Slide the Notifications panel open, and then tap
Call Settings for the slot you want to configure.
Preferred Card to set which card slot you'd like to use for most of your calls. The card's name will appear underlined on the
Phone dialer screen's call button. The corresponding send button in
Messages will also appear underlined when you're composing a new message.