Vail SIP TIM 1.0.4 supports SIP registrations with a SIP Proxy server but does not support authorization (username and password SIP registration.)

Vail recommends running the Vail SIP TIM behind a SIP Gateway, SIP Proxy, or other SIP agents such as Asterisk, which provides username and password registration services with a SIP service provider. You can then configure your preferred device(s) to forward calls to the Vail SIP TIM.