Starting today, the Google Voice Gateway is able to send SIP calls to your PBX with authentication. If the gateway receives a SIP 401 Unauthorized challenge to an INVITE, it will authenticate using the same username and password your equipment used to register.
This update allows those who are connecting to the Google Voice Gateway with a PBX to tighten their security, allowing calls only from known sources identified by IP address or authentication.
The new feature may be especially of interest to Asterisk users who have had to “allowguest=yes” and handle incoming GVGW calls as if they were anonymous due to Asterisk not being able to properly match peers using SRV or round-robin A records.
In short, to make use of this with Asterisk, set “allowguest=no” and “match_auth_username=yes” in sip.conf, then define your GVGW SIP peer as “type=friend” with the section name matching your GVGW account name. A more detailed tutorial will be available soon in the knowledge base.