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SIP settings
Transport: Choose type of transport, TCP ot UDP.
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Memory key: Field to enter direction to call when press INFO button on the handset.
Emergency call settings
Emergency call number: Field to enter direction to call when you pick up the handset for emergenct call.
Emergency call timeout: Choose timeout before call an emergency number.
NAT settings
NAT mode: Enable/disable NAT.
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STUN port: Field to enter STUN port.
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RTP port start: Field to enter start RTP port.
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