[call_center_internal]
exten => _1[0-8]X,1,Dial(SIP/${EXTEN},33)
exten => _1[0-8]X,2,Voicemail(${EXTEN}@call_center_vm)
exten => _19[0-7],1,Dial(SIP/${EXTEN},33)
exten => _19[0-7],2,Voicemail(${EXTEN}@call_center_vm)
exten => 199,1,Answer()
exten => 199,2,VoiceMailMain(${CALLERID(num)}@call_center_vm)
exten => _2XX,1,Goto(tech_support_internal, ${EXTEN},1)
exten => _3XX,1,Goto(accounting_internal,${EXTEN},1)
exten => _4XX,1,Goto(ceo_internal,${EXTEN},1)

[tech_support_internal]
exten => _2[0-8]X,1,Dial(SIP/${EXTEN},33)
exten => _2[0-8]X,2,Voicemail(${EXTEN}@tech_support_vm)
exten => _29[0-7],1,Dial(SIP/${EXTEN},33)
exten => _29[0-7],2,Voicemail(${EXTEN}@tech_support_vm)
exten => 299,1,Answer()
exten => 299,2,VoiceMailMain(${CALLERID(num)}@tech_support_vm)
exten => _3XX,1,Goto(accounting_internal,${EXTEN},1)
exten => _4XX,1,Goto(ceo_internal,${EXTEN},1)

[accounting_internal]
exten => _3[0-8]X,1,Dial(SIP/${EXTEN},33)
exten => _3[0-8]X,2,Voicemail(${EXTEN}@accounting_vm)
exten => _39[0-7],1,Dial(SIP/${EXTEN},33)
exten => _39[0-7],2,Voicemail(${EXTEN}@accounting_vm)
exten => 399,1,Answer()
exten => 399,2,VoiceMailMain(${CALLERID(num)}@accounting_vm)
exten => _4XX,1,Goto(ceo_internal,${EXTEN},1)

[ceo_internal]
exten => _4[0-8]X,1,Dial(SIP/${EXTEN},33)
exten => _4[0-8]X,2,Voicemail(${EXTEN}@ceo_vm)
exten => _49[0-7],1,Dial(SIP/${EXTEN},33)
exten => _49[0-7],2,Voicemail(${EXTEN}@ceo_vm)
exten => 499,1,Answer()
exten => 499,2,VoiceMailMain(${CALLERID(num)}@ceo_vm)
exten => _1XX,1,Goto(call_center_internal,${EXTEN},1)
exten => _2XX,1,Goto(tech_support_internal,${EXTEN},1)
exten => _3XX,1,Goto(accounting_internal,${EXTEN},1)