Attention T-Mobile and Telstra customers who are contemplating an iOS upgrade to the latest version 10. Don’t. At least not yet. According to several online reports the upgrade might cause connectivity issues with your phone. T-Mobile is supposed to be issuing a fix within the week.
I’m using iOS 10 with carrier settings 25.1 and an iPhone 6S+ and have yet to encounter anything unusual. However, some users on T-Mobile and Telstra say that after updating they found if the phone lost service temporarily that it would not reacquire a signal thus requiring a power off and on in order to re-connect.
Carrier settings updates let your carrier provider update carrier network and related settings to improve cellular network connectivity and performance or add support for features like VoLTE or Wi-Fi Calling.
If you’re curious what carrier version is on your device, look on your iPhone as follows:
- From the Home Screen, tap Settings.
- Tap General.
- Tap About.
- Scroll down to Carrier to view the current carrier version
Source: Macrumors