When we finally got the iPhone OS 3.1.2 update, we also got the 5.6 carrier update with it, but we had no freakin’ idea what it was supposed to do. According to iPhone Savior’s research, the guessing game is over: 5.6 was meant to fix issues with MMS, particularly the red exclamation point that occurs after many users try to send an image or video. [iPhone Savior]
https://gizmodo.com/iphone-os-3-1-2-is-out-solves-sleep-issue-at-last-5377317
