*CLI> zap show channels 
   Chan Extension  Context         Language   MusicOnHold         
 pseudo            default                                        
      1            default                                        
      2            default                                        
      4            default                                        
      5            default                                        

*CLI> Nov 15 13:21:03 DEBUG[-1228514384]: chan_sip.c:5200 check_user_full: Setting NAT on RTP to 1
Nov 15 13:21:03 DEBUG[-1228514384]: chan_sip.c:817 __sip_ack: Stopping retransmission on 'fdc9ab8bbfa3eb8d@172.24.45.36' of Response 19048: Found
Nov 15 13:21:03 DEBUG[-1228514384]: chan_sip.c:5200 check_user_full: Setting NAT on RTP to 1
Nov 15 13:21:03 DEBUG[-1228514384]: chan_sip.c:6991 handle_request: Check for res for festr2
Nov 15 13:21:03 DEBUG[-1228514384]: chan_sip.c:1633 update_user_counter: Call from user 'festr2' is 1 out of 0
Nov 15 13:21:03 DEBUG[-1228514384]: chan_sip.c:4423 build_route: build_route: Contact hop: <sip:festr2@172.24.45.36>
    -- Executing SetCallerID("SIP/festr2-0c09", """") in new stack
    -- Executing Dial("SIP/festr2-0c09", "Zap/g2||") in new stack
Nov 15 13:21:03 DEBUG[-1251439696]: app_dial.c:493 dial_exec: SIMPLE DIAL (NO URL)
Nov 15 13:21:03 NOTICE[-1251439696]: app_dial.c:727 dial_exec: Unable to create channel of type 'Zap'
  == Everyone is busy/congested at this time
Nov 15 13:21:03 DEBUG[-1251439696]: app_dial.c:990 dial_exec: Exiting with DIALSTATUS=CHANUNAVAIL.