Robocall prevention proposed in our solution involves 3 unique steps:

  • Prevent caller ID spoofing at the source.
  • Build a National Robocall registry that stores legal robocall numbers, and crowd-sourced illegal robocall numbers.
  • Provide capabilities for consumer to report illegal robocalls and provide indications to consumer that an incoming call may potentially be an illegal robocall. Caller ID Spoofing Caller ID Spoofing can only be caught at the originating carrier. Once the call leaves the originating carrier’s network, there is no way of identifying if the number presented in the caller ID is valid. FCC must make it mandatory to have every VoIP carriers confirm that the calls leaving their network has a valid non-spoofed caller ID, and must enforce strong penalties for violation, including loss of license. VoIP carriers already have tools at their disposal to make this happen. Before routing calls, every call is sent to a Local Number Portability (LNP) database to identify the terminating carrier and the “routing number” if the call is ported. Typically, this is done by sending the “SIP INVITE” (call signaling message in the VoIP environment) to the LNP database. By augmenting the LNP database to not only look at the terminating number, but also look at the source number and performing following verification, spoofing can be eliminated:
  • Verify that source number is a number that is allocated to originating carrier.
  • Verify that source number is not in the legal robocall list unless originating carrier is the provider for legal robocall entity. If the check fails, LNP database will reject the SIP INVITE with a not-authorized response, causing the call to fail if a spoofed identity is used. However, if the robocaller is using the caller ID of one of VoIP provider’s own customer, this method will fail. In such scenarios, the VoIP provider himself would be motivated to stop the practice, as one of his customers is harming another customer of him, which could potentially result in provider losing the good customer. This functionality can be implemented with minimal or no change on carrier’s side, and augmenting the LNP database services, which is may be provided by third party vendors. RoboCall Registry National Robocall registry will host a list of numbers belonging to legal robocall entities and numbers identified by consumers as illegal robocallers. Legal robocall numbers are registered directly by operators of legal robocalls, and are required to go through a verification process that validates the use of robocall for legal uses. This database is made available to LNP service providers to augment the LNP database for caller ID spoofing verification. Illegal robocaller numbers are populated by processing customer complaints. Customer complaints must first be run against legal robocaller list to make sure no legal entities are blocked, and a threshold is met before adding a particular number to robocaller. Customer may file complaints directly to robocall registry via a web portal or through their carrier by dialing a special code (such as *69) to report a call they just received. Processes on Terminating Carrier On the terminating carrier’s end, before delivering the call, a query to a caller name database is made to find out calling party’s name. Caller name database may be augmented with data from RoboCall registry to identify illegal robocalls, and a prefix may be added to the caller name (such as [Suspected RoboCall] “SRC: ”, for example “SRC: Card holder services”). This service can again be implemented with minimal changes on terminating carrier, as all carriers do Calling name database dips before delivering calls to customers. In addition, terminating carrier may incorporate additional steps such as forcing the caller to dial a “captcha” sequence before actually connecting the call to terminating party. This would require some major changes on terminating carrier’s network, but provides a much better protection from illegal robocalls. “Captcha” sequence would not be triggered for legal robocallers thereby allowing legal robocallers to proceed.
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