3CX

How to connect your 3CX system with Fonio

Note

Important: 3CX systems have a variety of settings on hosting and carrier levels that can cause issues when connecting.

We try to support as best as we can (Contact: support@fonio.ai), but due to the limited configuration options on our side, we cannot guarantee anything!

Recommended Setup Approach

For simpler setup and faster implementation, we recommend adding a Fonio number directly in your Fonio assistant and configuring a standard call forwarding (Rufweiterleitung) from your 3CX phone system to that Fonio number. This is the setup method used by most users and avoids complexity with SIP trunk configurations.

Create a trunk in 3CX

1. Navigate through the admin interface to the menu item Trunks & Chat.

2. Create a new trunk using the +Trunk button.

3. Select the option Generic SIP Trunk (IP Based).

   • Note: This option is only available for hosted systems.

Configure the 3CX trunk

1. Choose any name.

2. Enter the number through which Fonio should be reachable internally – this will later be prefixed.

3. Fill the Registrar field with:

vojhwtf1hn6.eu.sip.livekit.cloud

Restrict transport protocol

Set the transport protocol to TCP.

Create Fonio number

1. Navigate in Fonio to Phone Numbers → Add Number → Create SIP Number.

2. Create the number in Fonio using exactly the same number you entered above as the internal number.

Note: If the number is already in use by someone else, please choose a different one.

Important: SIP numbers configured in Fonio function as extensions of your phone system and are not directly reachable from outside. Callers must contact your main number first to reach the SIP number in Fonio.

Outgoing rule

1. Create an outgoing rule that defines when this trunk should be used.

   • Example: Prefix 999 (these digits will be stripped later).

2. Make sure the rule is placed above other rules that might override it.

Usage of the number

You can use the configured number, for example, for absence rules or call forwarding.

Critical: When configuring call forwarding in Fonio with a SIP number as the assistant's incoming number, all forwarding destinations must also be configured as SIP with their SIP URLs. Mixing SIP and external number types in forwarding configurations can cause forwarding failures.

Troubleshooting

Call forwarding shows "not reachable" or 403 Forbidden errors

If call forwarding between Fonio and 3CX fails with calls showing as "not reachable," check your error logs for SIP status codes. A code=permission_denied, message=twirp error unknown: sip status: 403: Forbidden, status=403 error indicates an issue with the 3CX connection, typically caused by an expired or misconfigured SIP trunk or authentication credentials. Verify the SIP trunk configuration and authentication settings in 3CX with your IT administrator.

Forwarding suddenly stopped working

If call forwarding failures occur without any configuration changes, try updating your 3CX system to the latest alpha version. This has resolved compatibility issues where forwarding stopped working with older 3CX versions.

Support

For questions or assistance, our team is always happy to help at
support@fonio.ai.