AT&T has started pushing out a new update to Samsung Galaxy S6, S6 edge+, and Galaxy Note5 units on its network. Carrying build numbers of G920AUCU4DPH5, G928AUCU3CPHA, and N920AUCU3CPHA respectively, the update brings along features such as AT&T Wi-Fi calling and Advanced Messaging. For the Galaxy S6 edge+ and Note5, the update also includes Android security update for the month of September. It's worth mentioning that the AT&T branded Samsung Galaxy S6 edge units aren't currently getting the update, but we expect that to happen soon. Source 1 2 3
Source: http://www.gsmarena.com/september_security_update_starts_hitting_at_t_galaxy_s6_s6_edge_and_note5-news-20625.php
