AT&T NumberSync with Compatible Apple Devices

AT&T曾經提供先前版本的APPLE裝置（WATCH或平板）採用VOICE OVER WI-FI電話來進行號碼同步服務。這個跟現在推出的APPLE WATCH 3 的做法不同。



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Set up NumberSyncSM between your iPhone® and a secondary device

Log in to your iCloud® and FaceTime® account on all compatible Apple devices you want to sync.

Make sure you’re logged in to iCloud and FaceTime with the same Apple ID on each device.

Set the FaceTime Caller ID to the mobile number of your iPhone.

From your iPhone, select Settings > Phone.

Select Wi-Fi Calling, move toggle to On position, follow prompts.

Once Wi-Fi Calling is on, select Calls on Other Devices.

If Allow Calls on Other Devices is off, move toggle to On.

All compatible Apple devices logged in to iCloud with the same Apple ID will be listed under Allow Calls On.

Select Add Wi-Fi Calling for Other Devices.

Follow screen prompts until you reach the NumberSync prompt.

Your other Apple device will display a pop-up to enable Wi-Fi Calling

If you don’t see a pop-up, turn on Calls from Phone, in your other device’s FaceTime settings.

A new pop-up now appears on:

The other Apple device with a 6-digit code.

At the same time, a pop appears on your iPhone requesting the code.

Enter the 6-digit code on your iPhone and tap Allow.

The other Apple device will display a pop-up about emergency calls, select Ok.

iPad – Go to FaceTime Settings > Update Emergency address

iPhone – Go to Settings > Phone > Wi-Fi Calling.