The STIR/SHAKEN protocol is a way to build trust with the people you're calling. When your company makes a call,
CM.com will add a digital signature to your call, which proves that the number displayed is genuinely from your business. In certain countries this is legally required. Calls may be dropped or rejected by the network if not signed, as mandated by law in those countries.
This is important because robocallers and scammers often "spoof" numbers, making it look like their calls are coming from legitimate businesses. With STIR/SHAKEN, your calls are marked as verified, so customers know they can trust that the call is really from you. This can lead to higher answer rates and better customer interactions, as people are more likely to pick up calls they know are legitimate.
Attestation levels
To gauge the confidence a carrier has in the legitimacy of a call, each call is assigned an attestation level. This level indicates how certain the carrier is that the caller is who they claim to be and that they are authorized to use the number being displayed. The attestation level helps determine the trustworthiness of the call, which is crucial for reducing spam and fraudulent calls.
There are three attestation levels:
- Full Attestation (A-level): The carrier has full confidence that the caller's identity is verified and that they are authorized to use the phone number shown. This is the highest level of trust.
- Partial Attestation (B-level): The carrier can verify the caller as a known customer but cannot confirm they are authorized to use the specific number displayed. This level represents moderate trust.
- Gateway Attestation (C-level): The carrier can only confirm that the call originated from their network but cannot verify the caller’s identity or the number being used. This is the lowest level of trust.
Attestation levels on the CM.com Voice platform
For outbound SIP trunking, when the call is placed with a phone number that’s in your CM.com Voice Account, which means it is visible in your Voice Management App, an A-level attestation will always be assigned. When the call is originated from a number that’s not hosted by CM.com, the attestation level will automatically be downgraded to C-level, since we cannot verify that we know who owns the number.
When you verify your SIP account by linking it to a company profile (which is a special administrative CM.com Voice entity that meets all legal requirements to own and operate phone numbers in a specific country/region), your call will be upgraded to B-level attestation.
Stir/shaken attestation levels for Voice SIP Trunking.
A SIP account can be verified by linking it to a company profile in the Voice Management App.
Voice API & Voice Campaigns
For the Voice API and Voice Campaigns, you can only receive an attestation A-level when you initiate the calls with numbers you own in the CM.com Voice platform. All calls created with other phone numbers will be downgraded to C-level.
Stir/shaken attestation levels for Voice API and Voice Campaigns.