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46 www.netcomm.com.au
fxo & fxS Impedence Setting
You can select the FXO & FXS Impedence Setting for a different country. Please leave as default unless
otherwise instructed.
options description
fxo Port Select Impedence for the FXO port. (only on V211)
fxS Port Select Impedence for the FXS port.
StUn Setting
You can enable/disable the STUN feature and configure the STUN Server IP address in this page. This function
can help your ATA to work properly behind a NAT device. To change these settings please follow your VoIP
Service Provider’s information.
options description
StUn When enabled the NetComm ATA uses STUN (Simple Transversal of UDP through NAT)
if the unit is behind a NAT enabled router and the router has no ALG for SIP, or NONE
to disable STUN (VoIP Gateway is not to use STUN for NAT traversal). VoIP Gateway
also supports a proprietary implementation of NAT traversal where the Service provider
is expected to provide some relay support. If NONE is selected, then based on the
responses received, the VoIP Gateway will dynamically determine if the SIP Server
supports the proprietary implementation.
note: even when StUn is enabled, the VoIP Gateway does an automatic detection of the presence of SIP
AlG and disables the use of StUn. this is to avoid some media problems arising out of the behavior of
some AlGs when StUn is used at the user end.
StUn Server Enter the IP address or host name of the STUN server.
StUn Port Enter the port number on which the STUN server listens for requests from the ATA.
(default : 3478)