STIR/SHAKEN is the caller-ID authentication framework the FCC requires voice providers to implement. Each call is signed by the originating provider with an attestation level that tells downstream carriers how confident it is that the caller is entitled to use the number shown.
Why attestation matters to call buyers
- A (full) attestation: the provider knows the customer and has verified their right to use the number.
- B (partial) attestation: the provider knows the customer but can't verify the number.
- C (gateway) attestation: the call entered the network from a source the provider can't verify.
Lower attestation can raise the chance that terminating carriers label or block calls, which shows up as lower connect rates and wasted media spend.
What to ask a traffic partner
- Which provider originates and signs the calls, and at what attestation level?
- How are numbers registered and monitored for spam labeling?
- How are transfers handled between platforms without losing call context?
Routing performance is only as good as the trust signals attached to each call. Treat attestation, number reputation and transfer design as part of your campaign setup, not an afterthought.