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innovaphone IP DECT
NAT and firewalls
If there is a firewall protecting your network from the Internet and connections
Calls can be set up to a
remote VoIP device,
but no voice
connections can be
established.
The media
channel cannot
be set up, since
the two VoIP
devices do not
have a common
voice encoder.
Only the media channel is set
up directly between the two
VoIP devices; all signalling
connections are operated via
the gatekeeper.
• Make sure that both VoIP
devices have a correct IP
routing configuration, in
particular subnet mask
and standard gateway.
Calls to a remote
telephony gateway are
constantly rejected.
The device does
not support
overlapped
sending.
• Add a hash (#) to the dial
prefix of the route leading
to this gateway to force
en-bloc dialling.
The VoIP device loses
its configuration after
it has been
disconnected from the
power supply.
The
configuration has
not been saved
in the non-
volatile memory.
• Save the configuration to
the non-volatile memory
each time you make any
changes.
The VoIP device is
connected to the
network behind a
firewall and the
configuration is not
working.
The firewall does
not allow access
to the VoIP
device.
• Enable VoIP device access
for the service tcp/80
(http) in the firewall.
The VoIP device is
connected to the
network behind a
firewall and no
connections to other
VoIP devices can be
established.
The firewall does
not support the
H.323 protocol.
• Enable “
H.323 Firewalling
”
in your firewall software
and, if necessary, “
H.323
NAT
”. Refer to your
firewall documentation for
this purpose.
• See chapter “
NAT and
firewalls
” for more
information.
Table 2
Troubleshooting
