-- Accepting call from '6049248118' to '6042888402' on channel 23, span 1
    -- Executing Dial("Zap/23-1", "SIP/6042888402@64.251.84.4") in new stack
Nov 13 04:31:05 DEBUG[163851]: chan_zap.c:1102 zt_enable_ec: Enabled echo cancellation on channel 23
Nov 13 04:31:05 DEBUG[344080]: chan_sip.c:821 create_addr: Setting NAT on RTP to 0
Nov 13 04:31:05 DEBUG[344080]: chan_sip.c:1026 sip_call: Outgoing Call for 6042888402
Nov 13 04:31:05 DEBUG[344080]: chan_sip.c:1125 find_user: 6042888402 is not a local user
    -- Called 6042888402@64.251.84.4
Nov 13 04:31:05 DEBUG[65541]: chan_sip.c:582 __sip_ack: Acked pending invite 102
Nov 13 04:31:05 DEBUG[65541]: chan_sip.c:600 __sip_ack: Stopping retransmission on '408db3837910f9da154bd6ad4d9ee8e6@209.139.247.39' of Request 102: Found
    -- Got SIP response 404 "Not Found" back from 64.251.84.4
    -- SIP/64.251.84.4-17dc is circuit-busy
Nov 13 04:31:05 DEBUG[344080]: chan_sip.c:1229 sip_hangup: find_user(6042888402) - decrement outUse counter
Nov 13 04:31:05 DEBUG[344080]: chan_sip.c:1125 find_user: 6042888402 is not a local user
  == Everyone is busy at this time
    -- Executing Hangup("Zap/23-1", "") in new stack
  == Spawn extension (pstn-in, 6042888402, 2) exited non-zero on 'Zap/23-1'
Nov 13 04:31:05 DEBUG[344080]: chan_zap.c:2188 zt_setoption: Set option AUDIO MODE, value: ON(1) on Zap/23-1
Nov 13 04:31:05 DEBUG[344080]: chan_zap.c:1717 zt_hangup: Hangup: channel: 23 index = 0, normal = 38, callwait = -1, thirdcall = -1
Nov 13 04:31:05 DEBUG[344080]: chan_zap.c:1134 zt_disable_ec: disabled echo cancellation on channel 23
Nov 13 04:31:05 DEBUG[344080]: chan_zap.c:2098 zt_setoption: Set option TDD MODE, value: OFF(0) on Zap/23-1
Nov 13 04:31:05 DEBUG[344080]: chan_zap.c:1077 update_conf: Updated conferencing on 23, with 0 conference users
Nov 13 04:31:05 DEBUG[344080]: chan_zap.c:2182 zt_setoption: Set option AUDIO MODE, value: OFF(0) on Zap/23-1
Nov 13 04:31:05 DEBUG[344080]: chan_zap.c:1134 zt_disable_ec: disabled echo cancellation on channel 23
    -- Hungup 'Zap/23-1'