Selection of preferred mechanisms for telephone number validation

A method for validating an association of a telephone number with a user equipment (UE) device by a registration server, the method comprising:

• by the registration server:
• receiving from the UE a mechanism-request message comprising an indication that the UE will request validation of the association by the registration server;
• generating, in response to receiving the mechanism-request message, an ordered list of mechanisms for the UE to use in attempting to validate the association, wherein generating the ordered list of mechanisms comprises ordering an available mechanism with a higher likelihood of successful validation ahead of an available mechanism with a lower likelihood of successful validation;
• transmitting the ordered list to the UE;
• receiving from the UE a validation request according to a particular mechanism of the mechanisms included on the ordered list;
• validating the association of the telephone number with the UE according to the particular mechanism in response to receiving the validation request;
• and
• transmitting to the UE a confirmation that the association has been validated.

A cellular communication device, comprising:

• at least one memory medium storing program instructions;
• at least one processing element configured to execute the program instructions to cause the cellular communication device to:
• transmit a mechanism-request message comprising an indication that the cellular communication device will request, from a registration server, validation that a particular telephone number has been assigned to the cellular communication device;
• receive, responsive to the mechanism-request message, an ordered list of mechanisms for validating that the telephone number has been assigned to the cellular communication device;
• select a first mechanism of the ordered list of mechanisms, based on the list order;
• and
• attempt the first mechanism of the ordered list of mechanisms, wherein the cellular communication device delays attempting any mechanism for validating that the telephone number has been assigned to the cellular communication device until after receiving the ordered list.