[customer1]
exten => 8005551212,1,Dial(SIP/customer1)
include => outgoing_us
include => outgoing_international

[customer2]
exten => 8005551313,1,Dial(SIP/customer2)
include => outgoing_us

[incoming]
exten => 8005551212,Goto(customer1,8005551212,1)
exten => 8005551313,Goto(customer2,8005551313,1)

[outgoing_us]
exten => _NXXNXXXXXX,1,Dial(SIP/1${EXTEN}@voiceconduits)
exten => _1NXXNXXXXXX,1,Dial(SIP/${EXTEN}@voiceconduits)

[outgoing_international]
exten => 011.,1,Dial(SIP/${EXTEN}@voiceconduits)