Phone number attestation

STIR/SHAKEN Phone Number Attestation Call Tester

Caller ID Reputation® provides Call Tester to test your phone number attestation rating. As a STIR/Shaken compliance metric, you can test your outbound phone calls with a generated number from our platform to see your current attestation level.

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Call Tester

Phone number transparency

Call Tester will provide you insights on the following:

  • Attestation Rating
  • CNAM
  • Certification
  • Verstat validation


Attestation Matters!

Rest easy knowing your outbound phone numbers are receiving the appropriate attestation level (A or B), to ensure you are properly connecting to your intended targets.

It’s important to know if your calls are signed and certified by both the OCN and terminating carriers. Attestation levels have a direct impact on the deliverability of your calls and more importantly, protect you from bad actors attempting to hijack your numbers with nefarious intent.

Attestation Matters

How STIR/SHAKEN Works in a Network

How STIR/SHAKEN works in a network

A SIP INVITE is received by the originating telephone service provider.

The originating telephone service provider checks the call source and calling number to determine how to attest for the validity of the calling number.

  • Full Attestation (A) — The service provider has authenticated the calling party and they are authorized to use the calling number.
  • Partial Attestation (B) — The service provider has authenticated the call origination, but cannot verify the call source is authorized to use the calling number.
  • Gateway Attestation (C) — The service provider has authenticated from where it received the call, but cannot authenticate the call source.

The originating telephone service provider uses the authentication service to create a SIP Identity header.

  • Calling number
  • Called number(s)
  • Current timestamp
  • Attestation level
  • Origination identifier

The SIP INVITE with the SIP Identity header is sent to the terminating telephone service provider. In addition, the Identity token may be sent across the internet, around non-SIP call segments, using Out-of-Band SHAKEN.

The SIP INVITE with Identity header is passed to the verification service.

The verification service obtains the digital certificate of the originating telephone service provider from the public certificate repository and begins a multi-step verification process. If all verification steps are successful, then the calling number has not been spoofed.

The verification service returns the results to the terminating service provider’s softswitch or SBC.

The call is completed to the called party.

Easy as Just 1-2-3

Your phone health matters

Easy as Just 1-2-3

Caller ID Reputation makes it easy for you to test your outbound numbers attestation— and best of all, this valuable tool is included with CIDR’s robust platform.

  • 1) Register your numbers on Caller ID Reputation
  • 2) Import the numbers you want to test with Call Tester
  • 3) Receive a report

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Caller ID Reputation

Allows your company to...

  • Check for flags across all major call blocking apps.
  • Upload large lists of phone numbers to check ratings.
  • Receive notifications in real time about flags.
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