Have you checked your apn? Settings-more networks-mobile networks-access port names. What apn is active?
Galaxy S4 M919N Unlocked to AT&T w/ AOSP 4.4.4
Galaxy S4 i337 Safestrapped w/ MYBA 4.4.2
Nexus 7 32Gb Multirom w/ Android L
Nexus 7 16Gb Multirom w/ Stock 4.4.4 and Ubuntu Desktop
Acer Iconia A500 w/ Beanstalk 4.4.4
SkyRocket i727 Powered by LiquidSmooth 4.4.4
"There is no dark side of the moon, really. As a matter of fact, its all dark"