A carrier can have certificates, signing infrastructure and STIR/SHAKEN enabled yet still produce inaccurate authentication results. The real challenge is keeping caller identity, number authorization, attestation, certificates and call signaling aligned as network conditions change.
For telecom operators authentication accuracy is therefore an operational discipline rather than a one-time configuration. When the information behind a call is correct and the supporting trust infrastructure remains synchronized carriers can provide more reliable identity signals to downstream networks while making troubleshooting easier.
1. Start With Accurate Caller Identity
Authentication Is Only as Good as the Data Behind It
STIR/SHAKEN uses digital certificates and cryptographic signatures to help verify that the calling number has not been falsely asserted. The originating provider evaluates the call source and calling number before creating the authenticated identity information. (TransNexus)
This means authentication accuracy starts before the call is signed.
Consider a carrier with a verified business customer that has recently added a new number. If the number has not been correctly associated with the customer's identity then the authentication system may have incomplete information even though the customer's overall account is legitimate.
A useful foundation is:
Customer Identity → Number Authorization → Authentication Policy → Call Signing
Keep Number Records Current
Carriers should maintain accurate relationships between customers and the numbers they are permitted to use.
Important controls include:
Customer identity validation
Number assignment records
Number ownership or authorization
Reseller relationships
Authentication eligibility
Changes to customer accounts
Twilio provides a practical example by associating phone numbers with approved Business Profiles during SHAKEN/STIR onboarding. Its documentation states that this association connects a single identity with the assigned phone numbers. (Twilio)
The broader principle applies regardless of platform: authentication should use current identity data rather than assumptions based on historical provisioning.
2. Make Attestation Decisions Consistent
Attestation Communicates What the Carrier Knows
Authentication accuracy is not simply about generating a signature. The attestation level needs to accurately represent the carrier's knowledge of the caller and the telephone number.
The standard levels are commonly described as:
A: The provider knows the caller and knows the caller has the right to use the number
B: The provider knows the customer but cannot establish the same level of number-use authorization
C: The call does not meet the requirements for A or B
Twilio documents these distinctions in its SHAKEN/STIR implementation. (Twilio)
Connect Attestation to Business Rules
Imagine a reseller that has been verified as a customer but supplies a number that the carrier cannot independently associate with that reseller.
The carrier should not treat the reseller's general customer status as automatic proof of number authorization.
This is where authentication accuracy depends on business processes as much as technical infrastructure.
A carrier can improve consistency by defining clear rules for:
Who is the customer? Who controls the number? What evidence supports authorization? Which attestation level corresponds to that evidence?
This creates a repeatable decision rather than leaving attestation to individual interpretation.
3. Strengthen Certificate Lifecycle Management
Valid Authentication Requires Valid Credentials
Certificates are a fundamental part of the STIR/SHAKEN trust chain. The terminating provider retrieves the originating provider's certificate and validates it before checking the signature. Verification includes factors such as certificate expiration and the validity of the issuing certificate authority. (TransNexus)
That means a carrier can have accurate customer information and still experience authentication problems if its certificate infrastructure is poorly managed.
Think of the certificate as a security credential. Knowing who the employee is does not help if the employee's access credential has expired.
Automate the Lifecycle
Certificate operations should cover:
Issue → Deploy → Monitor → Renew → Rotate → Revoke
Peeringhub provides STIR/SHAKEN certificate authority infrastructure with certificate enrollment, certificate management, delegated signing and developer automation. Its platform supports web-based workflows as well as API and Python tooling. (Peering Hub)
Automation can reduce dependency on manual reminders and help carriers maintain more consistent certificate operations.
For a growing carrier this becomes increasingly important because every additional signing environment introduces another certificate lifecycle to manage.
4. Validate the Identity Header and PASSporT
Do Not Treat Authentication as a Black Box
When authentication fails the first instinct may be to investigate routing or SIP connectivity.
However the Identity header itself can contain useful evidence about what happened.
TransNexus describes the STIR/SHAKEN verification process as checking the format and contents of the Identity header then validating the originating provider's signature and certificate. (TransNexus)
A carrier should therefore be able to inspect the complete authentication chain rather than only seeing a success or failure result.
Use Structured Inspection
Peeringhub's Identity Header Parser allows users to decode a STIR/SHAKEN Identity header and inspect information including:
Attestation
Origination
Destination
x5u
Algorithm
Signature status
PASSporT information
Its Certificate Inspector can inspect a certificate from pasted PEM content, a certificate URL or an uploaded .crt or .pem file. (Peering Hub)
This supports a more precise troubleshooting sequence:
Identity Header → PASSporT → Certificate → Signature → Verification
For example if the x5u points to an inaccessible certificate then the issue is different from an invalid signature. Separating these conditions helps engineering teams address the actual failure instead of repeatedly changing unrelated network settings.
5. Make Certificate Hosting Part of the Accuracy Strategy
Verification Depends on Certificate Availability
The certificate itself is only one part of the trust infrastructure.
The terminating provider needs to retrieve it from the certificate repository referenced by the authentication information. TransNexus notes that certificate acquisition time can depend on the distance between the verification service and repository and describes caching as one way to accelerate certificate retrieval. (TransNexus)
This creates a simple analogy: a valid identification document is not useful to a verifier if the system containing the supporting record cannot be reached.
Keep the x5u Path Reliable
Carriers should monitor:
Certificate URL accessibility
Correct x5u references
Certificate expiration
Certificate replacement
Repository availability
Public certificate consistency
Peeringhub provides STI-CR certificate hosting that allows providers to upload .crt certificates and receive public CDN-backed URLs for use in the Identity header's x5u reference. It also supports certificates generated by other certificate authorities. (Peering Hub)
This provides carriers with a dedicated option for keeping certificate publication separate from their primary application infrastructure.
6. Build Continuous Authentication Monitoring
Accuracy Should Be Measured Across Real Traffic
A carrier cannot improve authentication accuracy effectively if it only checks configuration.
Real traffic can reveal issues that configuration reviews do not.
Useful operational metrics include:
Percentage of calls receiving authentication
A/B/C attestation distribution
Identity header failures
Certificate validation failures
Certificate retrieval failures
Expired certificate events
Signature verification failures
Authentication changes after provisioning updates
TransNexus reported that 54.8% of calls at termination carried STIR/SHAKEN information in August 2026 within its measured provider dataset. It described this as its highest observed percentage while noting that it remained below the level needed to realize the full benefits of call authentication. (TransNexus)
The figure illustrates why monitoring matters. Having STIR/SHAKEN infrastructure does not necessarily mean every relevant call is being authenticated successfully.
Turn Errors Into Patterns
Suppose authentication failures increase immediately after a provisioning-system update.
That pattern could indicate that the new system is not passing caller identity information correctly.
If failures increase around certificate expiration dates then the certificate renewal workflow deserves investigation.
If verification failures are concentrated around certificate retrieval then repository performance or URL configuration may require attention.
The operational model becomes:
Detect → Classify → Investigate → Correct → Automate → Monitor
This is more effective than handling each failed call as an isolated incident.
7. Connect Authentication Accuracy With the Broader Telecom Architecture
Authentication Should Not Be an Isolated System
Modern carriers often operate across multiple platforms involving provisioning, routing, customer management, number inventory and security systems.
Authentication accuracy improves when these systems exchange reliable identity information.
A practical architecture can connect:
Customer Management ↓ Number Inventory ↓ Identity Validation ↓ Attestation Decision ↓ Certificate Management ↓ Call Authentication ↓ Verification and Monitoring
This approach reduces the number of manual handoffs where information can become inconsistent.
How Different Providers Approach the Problem
Different platforms address STIR/SHAKEN from different architectural perspectives.
Peeringhub focuses specifically on the trust infrastructure layer. Its platform combines certificate authority services with Identity Header parsing, Certificate Inspector, STI-CR hosting, OCN Lookup and developer automation. (Peering Hub)
TransNexus provides a broader STIR/SHAKEN environment covering authentication, verification and certificate management. Its documentation also focuses heavily on certificate repositories, key management and verification operations. (TransNexus)
Twilio integrates SHAKEN/STIR into its communications platform through Business Profiles, Trust Products and phone-number associations. Its onboarding can be performed through the Console or Trust Hub REST API. (Twilio)
These approaches are not identical. A carrier should evaluate how authentication infrastructure fits with its existing provisioning architecture, certificate requirements, customer model and automation strategy.
Conclusion: Authentication Accuracy Starts With the Entire Trust Chain
Improving carrier authentication accuracy is not about one configuration change. It requires consistent information across customer identity, telephone-number authorization, attestation, Identity headers, certificates and verification infrastructure.
The most practical approach is to treat authentication as a continuously managed operational process:
Verify identity → validate number authorization → apply accurate attestation → manage certificates → inspect authentication → monitor results
Peeringhub provides infrastructure specifically focused on this trust layer with STIR/SHAKEN certificate authority services, Identity Header analysis, certificate inspection, STI-CR hosting, OCN lookup and developer automation. (Peering Hub)
For carriers the objective is straightforward: make authentication decisions based on accurate information and keep the supporting infrastructure reliable throughout the life of the call.
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