VoIP: Asterisk route ke arah IP PBX lain dengan kode area

di sip.conf

[IPPBX-lain]
ipaddr = xxx.xxx.xxx.xxx

di extensions.conf

exten => _3.,1,Dial(SIP/${EXTEN:1}@IPPBX-lain,20,rt)

Referensi

• http://www.geekzone.co.nz/sbiddle/7183
• https://wiki.asterisk.org/wiki/display/AST/Pattern+Matching
• http://www.voip-info.org/wiki/view/Asterisk+config+sip.conf
• http://www.beardy.se/how-to-set-up-a-sip-trunk-in-the-asterisk-pbx