Something

mordor:/etc/asterisk # cat extensions.conf
[general]
static = no
writeprotect = yes
autofallthrough = no

[globals]
TRUNK=SIP/bv-trunk

[bvcontext]
exten => _X.,1,NoOp(Incoming Call from BroadVoice ${CALLERID} for ${EXTEN}@${SIPDOMAIN})
exten => _X.,2,Answer
exten => _X.,3,Wait(1)
exten => _X.,4,Background(moo1)
exten => _X.,5,Dial(SIP/100)

core set verbose 5:
    -- Executing [NXXNXXXXXX@bvcontext:1] NoOp("SIP/NXXNXXXXXX-081de138", "Incoming Call from BroadVoice  for NXXNXXXXXX@72.1.130.34") in new stack
    -- Executing [NXXNXXXXXX@bvcontext:2] Answer("SIP/NXXNXXXXXX-081de138", "") in new stack
    -- Executing [NXXNXXXXXX@bvcontext:3] Wait("SIP/NXXNXXXXXX-081de138", "1") in new stack
  == Spawn extension (bvcontext, NXXNXXXXXX, 3) exited non-zero on 'SIP/NXXNXXXXXX-081de138'