TATL flights always dock at a skybridge. Count a maximum of 10 min. walking from clearing immigration and another 5 min. after security to be at your departure gate. In other words doable if on time (even if somewhat "stressy"). Still, I also wonder why you chose this very tight connection when the next flight was less than 2 hours later. By the way, just to show you the worst case scenario, you arrive with a delay of about 30 min., get to the ticket office with a long line in front of you and then find out that there are no more seats available for the 11:50 flight (could easily be the case during the peak season)...