11-29-2015 2:10 PM
Setting at above link.
12-30-2015 10:18 AM
Is your phone unlocked? Please make sure you have a valid data plan and the data is turned on in the phone.
you can use these settigns posted here, which is exactly the one I'm using on my Galaxy phone
12-30-2015 11:00 AM
Those settings are dated and will not be updated. ATT support site is kept up to date and the settings are current for 4G LTE phones.