We are in the process of moving away from Microsoft SIP Gateway as we cannot depend on it to function 24/7. We are moving our phones to dual registration with our AudioCodes CE SBCs. Registration and Inbound calls work well but I am unable to get outbound calling to work. Has anyone achieved this with any other SBC.
The issue being the To header only has the number being dialled as shown here: <+123456789>.
The Invite sent from the phone is as follows and you can see this. The call fails because it has no hostname component as a suffix. For example if i manually dial +firstname.lastname@example.org the call will succeed without issue. How do i get the hostname part added by the phone when the call is made. I can't use SBC manipulation as the SBC see the incoming invite as none standard and throws an error.