Change Proposals for SHAKEN Documents

“iat” Content “iat” is “issued at” Claim It pertains to PASSPorT token, i.e. it needs to contain the time when it is constructed Technical Report on SHAKEN APIs for a Centralized Signing and Signature Validation Server 6.1 Datatype: signingRequest “Issued At Claim”: Should be set to the date and time of issuance of the PASSporT Token. No changes required 8.1.1 Functional Behavior The “iat” parameter is populated using the time of issuance of the PASSporT Token.

“iat” Content / Call Flow UE SBC/MRF SBC Another Operator INVITE Date: t1 183 t2 Announcement played Digits collected Time is now “t1 + t2” t3 INVITE Date: t1 Session will be routed to another carrier and therefore PASSPorT Token needs to be created Time is now “t1 + t2 + t3” Especially t2 could be substantial, e.g. 45 seconds, therefore using t1 from Date is problematic INVITE Date: t1 Identity: …

STI-AS/VS Overload A mechanism is needed to efficiently deal with STI-AS/VS overload This issue is addressed by HTTP/2 with a built-in mechanism Similar phenomena is observed for other protocols as well, e.g. SIP, Diameter Server indicates “drop rate” in 503 responses https://tools.ietf.org/html/draft-asveren-dispatch-http-overload-control-00 Work in progress and needs improvements, e.g. clarification about scope, retrying requests, introducing “validity time” parameter. Ideally this draft should progress but need “support” in IETF HTTP-bis WG Alternative is to carry this information as optional JSON parameters in responses “overloadIndicator”: { “drop rate”: “20%” “validity time”: “500” }

verstat “verstat” defined as a tel-URI parameter in TS 24.229 V14.4.0 (7.2A.20 "verstat" tel URI) by extending tel-URI syntax in RFC3966 par =/ verstat verstat = verstat-tag "=" verstat-value verstat-tag = "verstat" verstat-value = "TN-Validation-Passed" / "TN-Validation-Failed" / "No-TN-Validation" / other-value other-value = token To convey TN fidelity indication to UE For STIR/SHAKEN it should be defined as a parameter to be used by any header Proposal verstat-value = “Validation-Passed" / "Validation-Failed" / "TN-Validation" / other-value Which ATIS SHAKEN document should contain this syntax definition? Technical Report on SHAKEN APIs for a Centralized Signing and Signature Validation Server “6.7 Datatype: verificationResponse”: Remove “TN” from possible values “8.2.4.2 Mapping of verification failure cases to the returned SIP Reason header field parameters”: Remove “TN” from possible values “8.2.4.3 Response Sample (Success + Successful Validation)”: Remove “TN” “8.2.4.4 Response Sample (Success + Failed Validation)”: Remove “TN”

P-Attestation-Indicator For STIR/SHAKEN it should be defined as a parameter to be used by any header Proposal attestation-indicator = attestation-indicator-tag "=" attestation-indicator-value attestation-indicator-tag = “attestation-indicator" attestation-indicator-value = “A" / “B" / “C" / other-value other-value = token Which ATIS SHAKEN document should contain this syntax definition?

P-Origination-ID For STIR/SHAKEN it should be defined as a parameter to be used by any header Proposal origination-id = origination-id-tag "=" origination-id-value origination-id-tag = “origination-id" attestation-indicator-value = token Which ATIS SHAKEN document should contain this syntax definition?