I had that apn, but did not have 'hipri' listed in 'APN Type'
Seems to work now.
Originally Posted by Atma
The apn is what you need for data to work.
Go to settings > connections > more networks > mobile networks > access point names. You should see an apn for AT&T. If you don't you will need to add it. I have the T-Mobile S4 so I'm not sure what the settings would be for AT&T.
I found these for the AT&T S4. You can see if they work if you don't have it. Press your menu button and select New APN.
Name: ATT Phone
Proxy: Not set
Port : Not set
User name: Not set
Password: Not set
Server: Not set
MMS proxy: proxy.mobile.att.net
MMS port: 80
Authentication type: None
APN type: default,mms,supl,hipri
APN protocol: IPv4
APN roaming protocol: IPv4
Enable/disable APN: APN enabled