Mine

iax.conf REMOTE *

[general]
register => office:office@200.91.94.122

[celord]
type=friend
user=celord
secret=celord
host=dynamic
contex=incoming_celord



iax.conf LOCAL *

[general]
;autokill=yes
register => celord:celord@200.91.75.45

[office]
type=friend
user=office
secret=office
host=dynamic
contex=incoming_office




dial string on local machine:

exten => 600,1,Dial(IAX2/office/${EXTEN})