Advanced Consideration of a Caller Pre-Validation Against Direct Spam Over Internet Telephony
Spam over Internet Telephony as the distribution of unwanted voice messages over Voice over Internet Protocol networks is an upcoming threat. It is harder to prevent than e-mail spam since its content is not available before the victim is annoyed. This is even more difficult if the spam is sent directly to the victim's user equipment, bypassing the proxies of the service provider. Hence, these messages cannot be filtered, since the proxies are no longer participating in the transaction. This paper presents a pre-validation mechanism, which ensures a minimum level of trust about the caller.