Four Channel’s GSM VoIP Gateway
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3.4.4 Codec Preference
Codec Preference
allows a user to select the codes to be used and its priority to be
selected for a voice call.
Click on the check box to enable a codec. Select a codec and then press the UP or
DOWN button to move the position of the codec on the codec list with a priority in
descending order.
Note: The voice code alaw and ulaw is G.711a and G.711u.
3.4.5 NAT Traversal
3.4.5.1 H323 Signaling NAT Traversal
Signaling NAT traversal may be required if the GoIP400 Gateway is put behind a
NAT (or multiple NATs).
Depending on your network environment and SIP Server
capabilities, this feature may or may not be turn on.
A
）
None
Select
None
to turn off this feature.
B) Nat Citron
Citron
is a dedicated firewall penetration agreement for
GNUGK.
C) Port Transparent/DMZ
Port Transparent
refers that put network port of the
LAN
into computer or inside of
the
LAN
. The actual servers allow external users enjoy the servers of internal
server(
FTP
、
HTTP
、
Telnet)
.
D
）
Relay proxy
Relay proxy
is a proprietary NAT traversal technology. Please consult your service
provider for more information.
3.4.5.2 SIP Signaling NAT Traversal
