Simple Mobile Internet and MMS APN Settings for Windows Phone 8
Open cellular settings, in the App list, tap Settings > Cellular.
Select Data connection and turn this On.
Enable Highest connection speed
Tap Add Internet APN
Make below changes to the configuration
APN: simple
User name:
Password:
Proxy server (URL):
Proxy port:
IP type: IPv4
Tap Save
Done.
Open cellular settings, in the App list, tap Settings > Cellular.
Tap Add MMS APN
Make below changes to the configuration
APN: simple
Username:
Password:
WAP gateway (URL): proxy.mobile.att.net
Wap gateway port:80
MMSC (URL): http://smpl.mms.msg.eng.t-mobile.com/mms/wapenc
MMSC port:
Maximum MMS size: 1MB
IP type: IPv4
Tap Save
Done