Reply To: Sip trunk createio — QUALIFY

VitalPBX Community Support General Discussion Sip trunk createio — QUALIFY Reply To: Sip trunk createio — QUALIFY

    This feature (qualify) may also be used to keep a UDP session open to a device that is located behind a network address translator (NAT). By sending the OPTIONS request, the UDP port binding in the NAT (on the outside address of the NAT/firewall device) is maintained by sending traffic through it. If the binding were to expire, there would be no way for Asterisk to initiate a call to the SIP device. This can be used in conjunction with the nat=force,comedia setting.