[SR-Users] t_set_fr behaviour

hi guys, has anyone of you tried playing around with a scenario similar to this? A. invite -> t_set_fr() 2 seconds - if "100 trying" not received in 2 seconds, timeout. works fine. B. after receiving "100 trying" received, t_set_fr() 30 seconds - if 18x not received in 30 seconds, timeout. works fine C. after receiving the first 180, t_set_fr() 10 seconds - if "200 ok" not received in 10 seconds, it will not timeout, but instead it will timeout 30 seconds after B. i noticed this behavior recently and noticed that when a previous t_set_fr() is bigger than the new one, it will be ignored. so if i did 2 -> 10 -> 30, it works (swapping timeout values of B and C) my question is, is this an expected behavior? Kelvin Chua