hi bạn,
đây là context có thể tham khảo
vi /etc/asterisk/extensions.conf
[general]TRUNKA=SIP/voiptrunkTRUNKB=SIP/clickdialTRUNKC=DAHDI/g0
exten => _9044X.,1,Answer
exten => _9044X.,n,Set(Trunk=${RAND(1|3)})
exten => _9044X.,n,GoToIf($[${Trunk} = 1]?trunkA)
exten => _9044X.,n,GoToIf($[${Trunk} = 2]?trunkB)
exten => _9044X.,n,GoToIf($[${Trunk} = 3]?trunkC)
exten => _9044X.,n,Hangup
exten => _9044X.,n(trunkA),Dial(${TRUNKA}/${EXTEN:4},,tToR)
exten => _9044X.,n(trunkB),Dial(${TRUNKB}/${EXTEN:4},,tToR)
exten => _9044X.,n(trunkC),Dial(${TRUNKC}/${EXTEN:4},,tToR)exten => _9044X.,n,Hangup