To reduce or avoid multiple calls for authentication, during mobile device provisioning for broadband connectivity which might otherwise be caused by add-ons associated with a browser, a provisioning gateway or server system maintains a database of records of source addresses and associated mobile numbers. The records may also indicate time of last request from each address. In response to a new request, the system determines if there is a record for the source address. If there is a record, and in our example, if the record indicates that time since the last prior request is less than a threshold value, then the system continues provisioning processing for the device but without any communication with an authentication system. However, if there is no record or if the last request from a source address is older than the threshold, then the system communicates with the authentication system to obtain the directory number for the mobile device.