asterisk*CLI> zap show channels
   Chan Extension  Context         Language   MOH Interpret
 pseudo            default                    yes
      1            default                    yes
    -- Executing [9109@oficina:1] Dial("SIP/sip602-081d5690", "Zap/g2/109") in new stack
[May 15 19:34:17] WARNING[2549]: app_dial.c:1099 dial_exec_full: Unable to create channel of type 'Zap' (cause 0 - Unknown)
  == Everyone is busy/congested at this time (1:0/0/1)
  == Auto fallthrough, channel 'SIP/sip602-081d5690' status is 'CHANUNAVAIL'
asterisk*CLI>


exten => _91XX,1,Dial(${TRUNK}/${EXTEN:${TRUNKMSD}})