Please consider implementing TLS support on the SIP platform.
I recently installed "Bria" on my iDevice so I could use it as a wi-fi SIP handset, the problem with iDevices is they have a tendency to jump on any Wi-Fi network that has the same SSID as the major public providers (E.g Openzone.etc), It's possible this could lead to a situation where the Auth credentials are sent over an insecure Wi-Fi connection.
The App Supports using a TLS transport instead of UDP for SIP messaging, is it possible for AAISP to support this to improve secuirty when connecting on mobile devices that could potentially end up on un trusted networks?