[joe@asterisk]# cat /etc/asterisk/extensions.conf
[general]
static=yes
writeprotect=no
autofallthrough=yes
clearglobalvars=no
priorityjumping=no

[globals]
EXT200=SIP/200
EXT204=SIP/204

[invalid]

[myinternal]
exten => 111,1,Answer()
exten => 111,2,Playback(demo-echotest)
exten => 111,3,Echo()
exten => 111,4,Playback(demo-echodone)
exten => 111,5,Playback(vm-goodbye)
exten => 111,6,Hangup()

exten => 200,1,Dial(${EXT200})
exten => 204,1,Dial(${EXT204})

exten => group,1,LookupCIDName
exten => group,n,Dial(${EXT200}&${EXT204})