Please refer to the infrastructure chapter in the system requirements: Media data streams and signaling .

NAT type detection

The NAT type detection is a tool that can determine behind which NAT type the XPhone Connect Server or the XPhone Call Controller is operated. This helps to decide how you should configure.

You can either…

  • select a configured STUN server or

  • select the entry Additional STUN server

and click on the Detect NAT Type button.

You will get an overview of the used NAT type and also a recommendation how to solve the detected problems.

You can use the button Check reachability of this STUN Server if the XCC gets the correct public IP. The button can be used for the local XCC and also for the remote XCC.

STUN server

A STUN server makes it possible to determine the public IP address required for communication. Without a STUN server, no communication can take place via a NAT router (Internet), but only within the local network.

  • Click the Add button to add a new STUN server.

  • The Add STUN Server dialog window will open.

    • Configure a name.

    • Configure an IP address or FQDN of the STUN server.

    • Configure a port for the STUN server to be used (default 3478)

    • Optionally, you can enter a comment in the corresponding field.


If a STUN server is configured for the first time under System settings > Telephony & Meetings > Network, the XCC must be restarted afterwards under System settings > Telephony & Meetings > Telephony > SIP > XCC via Diagnosis. Otherwise, the XCC cannot determine its external IP and thus no media data connection can be established.

TURN server

A TURN server is used to enable communication between computers across NAT or firewall boundaries. The use of a TURN server requires the configuration of a STUN server. In the User management, assign sites or configuration groups a TURN server to be used for these users.

  • Click the Add button to add a new TURN server.

  • The Add STUN Server dialog window will open.

    • Configure a name.

    • Choose a provider:

      • You can choose the provider or

      • any other TURN server.

    • Configure the access data for the TURN server.

      • When selecting TURN server:

        • Host name or IP address

        • Port

        • Login name / Password

      • When selecting

        • Channel

        • Secret token

        • Username


        For this TURN provider you must have an account.

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