Configuring Remote Extensions - Auerswald COMpact 5200 Advanced Information

Functions, Uses, Concepts
VoIP

Configuring Remote Extensions

In order to operate a VoIP phone as a remote extension, it must either be
connected to the network via a VPN tunnel or the phone and the PBX must
establish the connection via a publicly accessible STUN server on the
Internet and a DynDNS service as described in the following.
Caution: Each port forwarding ares a security risk.
Important:
As a protection measure against the access by third parties, regularly
check the call data recording of your PBX and the LOGs of your NAT
router for inconsistencies.
For security reasons, the connection of remote extensions by means of
a VPN tunnel should be preferred.
Note that when using a remote extension, emergency calls can only be
traced backed to the location of the PBX (localisation). Localisation is
necessary if the caller is no longer able to give his name and address.
Therefore, for emergency calls from a remote extension, a mobile phone
or a phone connected to the local VoIP or public switched network is
required.
Note:
In order to avoid that emergency calls are made from a remote
extension, the prevention of emergency calls can be enabled under
Subscriber (scr.) > Properties > Exchange line settings. When the
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COMpact 5200/5200R/5500R - Firmware V7.2 - Advanced Information V04 07/2018
• You should use as few forwarding configurations as
possible.