To send incoming calls to a SIP client behind a NAT, CommuniGate Pro keeps the "communication hole" between the client and Server open by periodically sending dummy packets to that client.
Log Level: Use this setting to specify what kind of information the NAT Pinger component should put in the Server Log. Usually you should use the Major or Problems (non-fatal errors) levels. The NAT Pinger component records in the System Log are marked with the NATPING tag.
Clients Limit: Use this setting to specify how many different NAT clients the Server can ping.
Ping Clients Every: Use this setting to specify how often the Server should send its "pinging" packets to its clients using UDP and TCP protocols.