From sip.conf
=============

[201]
type=friend
context=default
secret=201
host=dynamic
dtmfmode=rfc2833
username=201
allow=ulaw
progressinband=no
mailbox=200@default

From extensions.conf
====================

[default]
exten => 200,1,VoiceMailMain(s200)
exten => 8500,n,Hangup

[numberplan-custom-1]
plancomment = DialPlan1
include = default
exten = _9.,1,Macro(trunkdial,${trunk_1}/${EXTEN:1})
comment = _9.,1,Outgoing,custom
exten = _999,1,Macro(trunkdial,${trunk_1}/${EXTEN:0})
comment = _999,1,UK Emergency Services,standard
exten = _112,1,Macro(trunkdial,${trunk_1}/${EXTEN:0})
comment = _112,1,EURO Emergency Services,standard

[incoming]
exten = s,1,Answer()
exten = s,n,Dial(SIP/201&SIP/202,10,r)
exten = s,n,Dial(SIP/203,10,r)
;exten = s,n,GotoIf($["${DIALSTATUS}" = "BUSY"]?103)
exten = s,n,VoiceMail(u200@default)
;exten = s,n,Playback(vm-nobodyavail)
exten = s,n,Hangup()

[DID_trunk_1]
;include = default
;exten = _X.,1,Goto(default|201|1)
;exten = s,1,Goto(default|201|1)
exten = s,1,Goto(incoming|s|1)