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Once you have taking the appropriate security considerations, continue to the Appliance Installation or Software version Installation (whichever applies to you)
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The most basic way to secure the SIP Network is to configure the SIP network to register to the NSG Gateway. By doing this, NSG will only accept calls from the trusted registered SIP Network device(s) and block/drop all other call attempts.
Registering your SIP network to NSG is trivial. If you an Asterisk or FreeSWITCH based PBX on the SIP Network, please follow these step-by-step instructions: Third Party Integration
Beyond the above approach, Sangoma recommends the installation of a Session Border Controller (SBC) appliance between the NSG Gateway and the SIP network devices. This will provide full security protection against all threats. Whether you purchase an SBC from Sangoma or a third party vendor, it should be installed as show in the picture below:
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