Inbound Verification
Voxtelesys signals STIR/SHAKEN verification results on inbound calls via SIP headers so your equipment or application logic can act on call authenticity data.
Verification Modes
Voxtelesys supports three inbound verification modes, configurable per trunk. The mode controls which SIP parameters and headers are added to calls delivered to your endpoint.
| Mode | Description |
|---|---|
| Off | No verification is performed and no STIR/SHAKEN headers are added or modified |
| Basic Verification | Adds a verstat parameter to the P-Asserted-Identity SIP header indicating the validation result |
| Enhanced Verification | Basic Verification plus P-Attestation-Indicator and P-Origination-ID SIP headers for additional verification data |
Off
In Off mode, calls are delivered without any STIR/SHAKEN headers added or modified.
Basic Verification
In Basic Verification mode, a verstat parameter is appended to the P-Asserted-Identity header. This parameter reflects the outcome of the STIR/SHAKEN signature validation.
| Value | Description | Interpretation |
|---|---|---|
TN-Validation-Passed | The Identity header signature was present and validated successfully | The carrier has confirmed that the caller is authorized to use the specific phone number. Typically shown as a "Verified" checkmark on smartphones. |
TN-Validation-Failed | The Identity header was present but signature validation failed | The call may have been tampered with in transit or the signature was forged by an unauthorized entity. |
No-TN-Validation | No Identity header was present or validation was not performed | No verification was attempted. This is common for calls originating from older "TDM" (landline) networks or international gateways that don't support the protocol yet. |
Example:
P-Asserted-Identity: <sip:[email protected];verstat=TN-Validation-Passed>
Enhanced Verification
In Enhanced Verification mode, the attestation level and origination identifier are provided in the following SIP headers:
| Header | Description |
|---|---|
P-Attestation-Indicator | The attestation level assigned by the originating carrier (A, B, or C) |
P-Origination-ID | A unique call identifier used for STIR/SHAKEN traceback |
Example:
P-Asserted-Identity: <sip:[email protected];verstat=TN-Validation-Passed>
P-Attestation-Indicator: A
P-Origination-ID: c7c5f938-3064-47a7-b1c5-698ee934eacd