Telnyx STIR/SHAKEN Guide

This guide explains what STIR/SHAKEN attestation level Telnyx will provide for different call scenarios.

• Telnyx will give Attestation Level A

• Telnyx will give Attestation Level B

• If you make a call from a US number to any destination:
  • Telnyx will give attestation using Telnyx's US certificate
• If you make a call from a Canadian number to a Canadian number:
  • Telnyx will give attestation using Telnyx's Canadian certificate
• If you make a call from a Canadian number to a US number:
  • Telnyx will give attestation using Telnyx's US certificate

If you have call forwarding enabled on your Telnyx number and receive an inbound call:

• Telnyx will add a DIV (diversion) passport for the forwarded leg
• The original STIR/SHAKEN passport is preserved or passed through
• Telnyx generates Attestation Level A for the forwarded leg

• If your forwarded call goes from US to US:

  • Telnyx will give DIV attestation using Telnyx's US certificate
  • Attestation Level A for the forwarded leg

• If your forwarded call goes from Canada to Canada:

  • Telnyx will give DIV attestation using Telnyx's Canadian certificate
  • Attestation Level A for the forwarded leg

• If your forwarded call crosses borders (US ↔ Canada):

  • Telnyx will give DIV attestation using Telnyx's US certificate
  • Attestation Level A for the forwarded leg

1. Alice calls your Telnyx number (which has call forwarding to Bob)
2. Telnyx automatically forwards the call to Bob
3. Bob receives a call with:
   • Original STIR/SHAKEN passport (if any)
   • DIV passport with:
     • From: Alice's number
     • To: Forwarded number
     • Attestation Level A

Call transfers can be initiated through different methods, and Telnyx handles STIR/SHAKEN attestation differently for each:

If you transfer a call by sending a SIP REFER message:

• The original STIR/SHAKEN passport is not preserved or passed through
• Telnyx generates Attestation Level B

1. Alice calls Bob (with Level A attestation)
2. Bob transfers the call to Carol using SIP REFER
3. Carol receives a call with STIR/SHAKEN passport showing:
   • From: Alice's number
   • To: REFERred number
   • Attestation: Level B

If you transfer a call using the Call Control API transfer command:

• Telnyx generates Attestation level according to the rules outlined in "Simple Outbound Call Scenarios" based on the from number
• The original STIR/SHAKEN passport is not passed through

If you use Call Control API dial and bridge commands:

• Telnyx generates Attestation level according to the rules outlined in "Simple Outbound Call Scenarios" based on the from number
• The original STIR/SHAKEN passport is not passed through

If you transfer a call using TeXML <Dial>:

• Telnyx generates Attestation level according to the rules outlined in "Simple Outbound Call Scenarios" based on the from number
• The original STIR/SHAKEN passport is not passed through

Transfer Method	Origination Number	Attestation Level	Original Passport
SIP REFER	Original caller	B	Not preserved
API Transfer	Set by user	A or B*	Not preserved
API Dial/Bridge	Set by user	A or B*	Not preserved
TeXML Dial	Set by user	A or B*	Not preserved

*Attestation follows the rules outlined in "Simple Outbound Call Scenarios"