exten => _X.,1,Dial(ZAP/g1/${EXTEN})
exten => _X.,2,Congestion
exten => _X.,102,Busy
gives this on the * CLI

    -- Extension 's' in context 'from-internal' from '' does not exist.  Rejecting call on channel 0/31, span 2

################################################################

;exten => s,1,Dial(ZAP/g1/${EXTEN})
;exten => s,2,Congestion
;exten => s,102,Busy
gives this on the * CLI


  -- Accepting call from '' to 's' on channel 0/31, span 2
    -- Executing [s@from-internal:1] Dial("Zap/62-1", "ZAP/g1/s") in new stack
    -- Requested transfer capability: 0x00 - SPEECH
    -- Called g1/s
    -- Zap/1-1 is proceeding passing it to Zap/62-1
    -- Channel 0/1, span 1 got hangup request, cause 28
    -- Hungup 'Zap/1-1'
  == Everyone is busy/congested at this time (1:0/0/1)
    -- Executing [s@from-internal:2] Congestion("Zap/62-1", "") in new stack
    -- Channel 0/31, span 2 got hangup request, cause 16
  == Spawn extension (from-internal, s, 2) exited non-zero on 'Zap/62-1'
    -- Hungup 'Zap/62-1'