dev-asterisk*CLI> pri debug span 3
Enabled debugging on span 3
dev-asterisk*CLI> pri debug span 4
Enabled debugging on span 4
    -- Accepting call from '8018285230' to '8017037001' on channel 0/4, span 1
    -- Executing Dial("Zap/4-1", "Zap/g2/8017037001") in new stack
Aug 31 22:22:16 NOTICE[29444]: app_dial.c:1040 dial_exec_full: Unable to create channel of type 'Zap' (cause 34 - Circuit/channel congestion)
  == Everyone is busy/congested at this time (1:0/1/0)
    -- Channel 0/4, span 1 got hangup request
       > cdr_odbc: Error SQLConnect -1
    -- Hungup 'Zap/4-1'
dev-asterisk*CLI>