Help > Functions and applications > VoIP > External Private Branch Exchanges
External Private Branch Exchanges
The PBX handles external extensions in the same way as internal VoIP telephones.
*Further help under Internal IP telephony
VoIP telephones are connected to the PBX network via a VPN tunnel.
*Note: If necessary, contact your network administrator to find out the VPN settings.
*Further help under VPN
*Important: When configuring an external extension, remember that these telephones can only make emergency calls if specific requirements have been met.
*Further help under Emergency calls
*Important: When setting up an external extension, please note that the availability of an NTP server must also be guaranteed for these telephones.
*Further help under Date and Time