Strange dialing

hi：
Could you check this log, please reset the limitation in trunk and have a try:
-- Got SIP response 480 "Trunk Concurrency Limit Reached" back from 192.159.66.3:5060
[2015-11-26 12:49:06] VERBOSE[19651][C-00001209] app_dial.c: -- SIP/fpbx-1-W7qTJLasDxCa-000005c5 is circuit-busy
[2015-11-26 12:49:06] VERBOSE[19651][C-00001209] app_dial.c: == Everyone is busy/congested at this time (1:0/1/0)