1. Change Proposals for SHAKEN Documents

2. “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.

3. “iat” Content / Call FlowUE
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: …

4. 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
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” }

5. verstat
“verstat” defined as a tel-URI parameter in TS V (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
“ Mapping of verification failure cases to the returned SIP Reason header field parameters”: Remove “TN” from possible values
“ Response Sample (Success + Successful Validation)”: Remove “TN”
“ Response Sample (Success + Failed Validation)”: Remove “TN”

6. 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?

7. 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?