Auerswald COMpact 4000 Operation Manual page 594

Settings
VoIP
VoIP Provider Settings
Time limit for registration (1 to 60 min.)
The registration time specifies how many minutes the PBX waits before reregistering itself with
the VoIP provider.
Note: In the test phase, after configuring the VoIP provider, we recommend
you enter a low value (e.g. three minutes). After completing the test phase,
you can enter a much higher value, since some VoIP providers also reject
calls if too many attempts are made to register.
SIP registration in accordance with RFC 6140
The PBX complies with the SIPconnect 1.1 SIP protocol.
NAT traversal
NAT (Network Address Translation) enables you to convert a particular IP address that is used
within a network (e.g. a local network) into a different IP address that can be used by a different
network (e.g. the public switched telephone network). If NAT traversal is switched on, and a
query is sent from a local IP address to the public network, the sending IP address is swapped
with the public IP address. This function is performed in the reverse direction for the reply.
Disabled: NAT traversal is not performed by the PBX. The router which connects the local area
network with the Internet should be a properly functioning, SIP-aware router which performs
NAT traversal.
Enabled with use of STUN: NAT traversal is performed by the PBX. To achieve this, a STUN
server must also be specified for the VoIP provider.
Enabled: NAT traversal is performed by the PBX. To achieve this, the registrar for the VoIP
provider must be switched on. The SIP request also contains an "rport" part in which the IP
addresses used here (local, public) are transported.
Notes:
If Enabled is selected: If problems occur with single-sided call connections,
use Enabled with use of STUN instead.
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Caution: Each time a port is opened on the router, this creates a
potential source of danger.
• It is essential you put additional protective measures in place.
COMpact 4000 - Firmware V6.6A - Installation, Operation and Configuration V03 03/2016