Someone

U 192.168.1.100:5060 -> 64.192.196.12:57814
  SIP/2.0 404 Not Found..Via: SIP/2.0/UDP  64.192.196.12:5060;received=64.192.196.12..From: "unknown" <sip:unknown@64.192.196.12>..To: <sip:525559990000@
  71.79.13.224;user=phone;phone-context=unknown>;tag=as62fb57b0..Call-ID: AC6FF3F7-C42411CC-9631AB09-44892754@64.192.196.12..CSeq: 101 INVITE..User-Agent
  : Asterisk PBX..Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY..Supported: replaces..Content-Length: 0....

U 64.192.196.12:57814 -> 192.168.1.100:5060
  ACK sip:525559990000@71.79.13.224;user=phone;phone-context=unknown SIP/2.0..Via: SIP/2.0/UDP  64.192.196.12:5060..From: "unknown" <sip:unknown@64.192.1
  96.12>..To: <sip:525559990000@71.79.13.224;user=phone;phone-context=unknown>;tag=as62fb57b0..Date: Sat, 09 Oct 1993 23:18:27 GMT..Call-ID: AC6FF3F7-C42
  411CC-9631AB09-44892754@64.192.196.12..Max-Forwards: 6..CSeq: 101 ACK...

extensions.conf

[general]
static=yes
writeprotect=no
autofallthrough=no
clearglobalvars=no

[globals]
DIAL_OPTIONS = tr
TRUNK_OPTIONS = r
OUTFAIL_1 =
OUTMAXCHANS_1 =50
OUTPREFIX_1 =00
OUT_1 = SIP/VD-OUT

[inbound]
exten => _X.,1,Macro(dialout-trunk,1,${EXTEN},,)
exten => _X.,n,Macro(outisbusy,)

[macro-dialout-trunk]
exten => s,1,Set(DIAL_TRUNK=${ARG1})
exten => s,n,Set(DIAL_NUMBER=${ARG2})
exten => s,n,Set(DIAL_TRUNK_OPTIONS=${DIAL_OPTIONS})
exten => s,n,Set(GROUP()=OUT_${DIAL_TRUNK})
exten => s,n,Set(DIAL_TRUNK_OPTIONS=${TRUNK_OPTIONS})
exten => s,n,GotoIf($["${OUTMAXCHANS_${DIAL_TRUNK}}foo" = "foo"]?nomax)
exten => s,n(checkmax),GotoIf($[ ${GROUP_COUNT()} > ${OUTMAXCHANS_${DIAL_TRUNK}} ]?chanfull)
exten => s,n,Set(OUTNUM=${OUTPREFIX_${DIAL_TRUNK}}${DIAL_NUMBER}) ; OUTNUM is the final dial number
exten => s,n,Dial(${OUT_${DIAL_TRUNK}}/${OUTNUM},300,${DIAL_TRUNK_OPTIONS}) ; Regular Trunk Dial
exten => s,n,Goto(s-${DIALSTATUS},1)
exten => s,n(chanfull),Noop(max channels used up)
exten => s-BUSY,1,NoOp(Dial failed due to trunk reporting BUSY - giving up)
exten => s-BUSY,2,Busy(20)

exten => s-NOANSWER,1,NoOp(Dial failed due to trunk reporting NOANSWER - giving up)
exten => s-NOANSWER,2,Playtones(congestion)
exten => s-NOANSWER,3,Congestion(20)

exten => s-CANCEL,1,NoOp(Dial failed due to trunk reporting CANCEL - giving up)
exten => s-CANCEL,2,Playtones(congestion)
exten => s-CANCEL,3,Congestion(20)

exten => _s-.,1,GotoIf($["x${OUTFAIL_${ARG1}}" = "x"]?noreport)
exten => _s-.,n,AGI(${OUTFAIL_${ARG1}})
exten => _s-.,n(noreport),Noop(TRUNK Dial failed due to ${DIALSTATUS} - failing through to other trunks)

exten => disabletrunk,1,Noop(TRUNK: ${OUT_${DIAL_TRUNK}} DISABLED - falling through to next trunk)

exten => h,1,Macro(hangupcall)


[macro-outisbusy]
exten => s,1,Playback(all-circuits-busy-now,noanswer)
exten => s,n,Playback(pls-try-call-later,noanswer)
exten => s,n,Macro(hangupcall)

; What to do on hangup.
[macro-hangupcall]
exten => s,1,ResetCDR(w)
exten => s,n,NoCDR()