T38 Fax Trunk Settings

Briva Voice support manages service activation and trunk configuration. The technical settings below are for authorized administrators; ask support to confirm the settings available for your account.

Briva Voice support manages service activation and trunk configuration. The technical settings below are for authorized administrators; ask support to confirm the settings available for your account.

The Briva Voice T38 IP Fax solution is compatible with all customer premise equipment, both SIP enabled and analog based. 

However, we ONLY recommend the use of the Netgen Fax ATA described in our T.38 Fax Overview article.

While no IP Fax service or hardware of ANY technology can be 100% guaranteed for reasons outside of our control, it is our experience that by using the Netgen ATA bundled with our T38 optimized routing customers can enjoy a reliable faxing solution near landline quality results.

In our testing of our service with the Netgen ATA we have successfully and repeatedly sent multiple 40+ page faxes while connected through a Cable and DSL internet circuit.



In this article we will cover.
  • How to Manage an Active T38 IP Fax Trunk
  • Connect and Route via Registration
  • Outbound Caller ID


To Manage an Active T38 IP Fax Trunk.

1. Contact Briva Voice support to confirm the settings and access available for your SIP service.

2. Go to the SIP Trunk page and click the Settings icon for the Trunk you want to manage.




Connect and Route Calls via Registration with SIP Credentials.

By default Fax Trunks are configured for Registration based routing with credential based authentication. This is the most common configuration and easiest to setup for most customer premise equipment. 

The credentials and server details are located in the Registration Details window. In most cases all you need to configure your device is the Username, Password and SIP Server. To see the password click the Show button.

Once a device has successfully registered (connected to the Briva Voice Platform) the Status will show Online and the registration details will show below.

*Note: If your device shows online but the portal shows Offline your device is NOT properly connected. Issues with NAT on the local LAN and SIP ALG can cause this to happen.




Outbound Caller ID

By default, Fax Trunks behave in 'pass-thru' mode. This means the Briva Voice platform will proxy any caller ID provided by the customer equipment. Caller ID manipulations should be performed in the customer equipment. It is important that any caller ID used for emergency calls is an active number with a valid e911 registration.

If you cannot manage the caller ID on the customer equipment or need to override it for any reason, click the Caller ID Override toggle to ON and enter a valid US phone number. When enabling this feature, the Briva Voice platform will ignore any caller ID values sent by the customer equipment and send the input value instead.