1、 ATIS-1000081 ATIS Standard on ATIS Technical Report on a Framework for Display of Verified Caller ID Alliance for Telecommunications Industry Solutions Approved May 2018 Abstract This technical report provides a framework for signaling verified Caller ID information from the network to a User Equip
2、ment (UE) and displaying the information on the UE in a uniform manner, independent of technology. The main goal is to provide display guidelines that help empower consumers in managing their calls, as per the Robocalling Strike Force recommendations. ATIS-1000081 ii Foreword The Alliance for Teleco
3、mmunication Industry Solutions (ATIS) serves the public through improved understanding between providers, customers, and manufacturers. The Packet Technologies and Systems Committee (PTSC) develops and recommends standards and technical reports related to services, architectures, and signaling, in a
4、ddition to related subjects under consideration in other North American and international standards bodies. PTSC coordinates and develops standards and technical reports relevant to telecommunications networks in the U.S., reviews and prepares contributions on such matters for submission to U.S. Int
5、ernational Telecommunication Union Telecommunication Sector (ITU-T) and U.S. ITU Radiocommunication Sector (ITU-R) Study Groups or other standards organizations, and reviews for acceptability or per contra the positions of other countries in related standards development and takes or recommends appr
6、opriate actions. The SIP Forum is an IP communications industry association that engages in numerous activities that promote and advance SIP-based technology, such as the development of industry recommendations, the SIPit, SIPconnect-IT, and RTCWeb-it interoperability testing events, special worksho
7、ps, educational seminars, and general promotion of SIP in the industry. The SIP Forum is also the producer of the annual SIP Network Operators Conference (SIPNOC), focused on the technical requirements of the service provider community. One of the Forums notable technical activities is the developme
8、nt of the SIPconnect Technical Recommendation a standards-based SIP trunking recommendation for direct IP peering and interoperability between IP Private Branch Exchanges (PBXs) and SIP-based service provider networks. Other important Forum initiatives include work in Video Relay Service (VRS) inter
9、operability, security, Network-to-Network Interoperability (NNI), and SIP and IPv6. Suggestions for improvement of this document are welcome. They should be sent to the Alliance for Telecommunications Industry Solutions, PTSC, 1200 G Street NW, Suite 500, Washington, DC 20005, and/or to the SIP Foru
10、m, 733 Turnpike Street, Suite 192, North Andover, MA, 01845. The mandatory requirements are designated by the word shall and recommendations by the word should. Where both a mandatory requirement and a recommendation are specified for the same criterion, the recommendation represents a goal currentl
11、y identifiable as having distinct compatibility or performance advantages. The word may denotes an optional capability that could augment the standard. The standard is fully functional without the incorporation of this optional capability. The ATIS/SIP Forum IP-NNI Task Force under the ATIS Packet T
12、echnologies and Systems Committee (PTSC) and the SIP Forum Technical Working Group (TWG) was responsible for the development of this document. ATIS-1000081 iii Table of Contents Scope, Purpose, This document is available from the Federal Communications Commission at . 2This document is available fro
13、m the Alliance for Telecommunications Industry Solutions (ATIS) at . ATIS-1000081 2 Ref 2 3GPP TS 22.173, IP Multimedia Core Network Subsystem (IMS) Multimedia Telephony Service and supplementary services.3Ref 3 3GPP TS 24.196, Technical Specification Group Core Network and Terminals; Enhanced Calli
14、ng Name.4Ref 4 IETF RFC 8224: “Authenticated Identity Management in the Session Initiation Protocol (SIP)“.5Ref 5 3GPP TS 24.229: “IP Multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3“.6Ref 6 3GPP TS 29.165: “Inter-IP Multimed
15、ia System (IMS) Network to Network Interface (NNI) (Release 15)“.73 Definitions, Acronyms, i.e., an “Anonymous“ message would be displayed for name and TN. a. The terms of agreement between the service provider and the analytics provider are expected to require preservation of the callers privacy. b
16、. Further clarification and/or safe harbors are needed to determine whether the name and TN could be anonymized while additional call information, such as call category and potential fraud risk, could be delivered to help empower the end user. 5) Where delivery of the final call information display
17、is not delegated to an analytics provider, the service provider is expected to adhere to the application of privacy rules for the calling number and name portions of the display; i.e., an “Anonymous“ message would be displayed for name and TN. 6) In the absence of clarification or any special allowa
18、nces on handling private calls, the guidelines herein call for anonymizing ALL call information if the received calling number is anonymous. The determination of the authentication of the call is NOT “call information” in the traditional sense and should be presented to the user independent of legit
19、imate privacy uses. 7) The end user may subscribe to multiple mitigation services. Order and preference of display may be determined by the service provider. Variations in operating systems and the plethora of available applications make it impractical to set interoperability or prioritization guide
20、lines. Therefore, it is the responsibility of end users to select the mitigation service that best meets their needs. 5.3 Available Call-related Information The data outputs from the network and CVT will be at the center of the message delivered to the user (e.g., warning or other). Making more reli
21、able information available to the CVT algorithms is likely to yield more accurate results for the user. Therefore, it is recommended that attestation levels and identifiers from SHAKEN be made available to the CVT function, according to local policies. 5.4 Preliminary Display Usability & Comprehensi
22、on Studies Over the course of Q2 and Q3 2017, Hiya Inc. conducted several usability studies targeted at the display guidelines of the STIR/SHAKEN protocol. The studies and their results are provided later in this clause. The goals of the study were twofold: 1. To measure the potential impact of a po
23、sitive assurance indication for verified calls (the “green checkmark”). 2. To assess various textual and iconographic display options for caution indicators on suspicious calls. ATIS-1000081 8 Hiya conducted three brief usability studies on different audiences: 1. A user comprehension and influence
24、study on robust caller profiles and certified call markers. 2. A user impact analysis of various phrasings and iconography for suspicious call messaging. 3. A call pickup rate impact analysis of a “certified” checkmark icon against existing Hiya users. 5.4.1 Study #1: Comprehension & Impact of Certi
25、fied Call Markers 5.4.1.1 Study Description Hiya interviewed 11 randomly chosen individuals among a pool of volunteers to participate in a paper-based usability study. Participants were offered no context or explanation of STIR/SHAKEN or the purpose of the study. Participants were presented with a s
26、equence of incoming call User Interface (UI) mockups and asked a series of questions: What do you notice about this screen? What confidence or trust do you have in this caller information? What effect does this have on your opinion of previous screens (if any)? The mockups were designed to enhance t
27、he incoming call experience with expanded caller profile information, with the final mockup showing a “certified call” confirmation reflective of STIR/SHAKEN validation. Interviews lasted an average of 35 minutes per participant. 5.4.1.2 Results In nearly all cases (10/11), participants showed a “st
28、rong” or “very strong” indication that additional caller profile information strengthened their confidence in the legitimacy of the theoretical phone call. This applied across all mockups, prior to “certified call” marker. For the “certified call” mark, A significant number of participants (8/11) id
29、entified the mark as reassurance to the legitimacy of the call, and all who identified this also expressed future doubts to the legitimacy of any future call lacking the indication. Some (6/11) expressly stated that they would become less likely to answer any unknown call lacking certification, once
30、 the certification marker was seen. 5.4.1.3 Conclusions Hiya has concluded that the use of such a marker with clear context would negatively impact all calls lacking this marker. It remained unclear from the study if the marker would have a positive impact on pickup rates for marked numbers. (Hiya h
31、as previously demonstrated that extended call profile information positively influences call pickup rates, without any “certified call” indication.) 5.4.2 Study #2: Call Pickup Rate Test 5.4.2.1 Study Description Hiya selected 70 high-volume (in excess of 600 monthly observed calls) legitimate busin
32、ess phone numbers from Canada with varying pre-existing caller profile information. These numbers were chosen because of Hiyas subscription rate in Canada. ATIS-1000081 9 Call creation rates and user pickup rates were monitored for these numbers over a two-week period, during which Hiya caused the d
33、isplay of a simple white checkmark to be shown for any Smart Call user. After two weeks, the checkmark was removed, and call volume and pickup rates were measured for an additional two weeks. 5.4.2.2 Results It is important to note that Hiya could not identify or control the individuals receiving ph
34、one calls from the selected businesses. Therefore, it is not possible to confirm the results of Study #1 (that individual pickup rates would drop as users become familiar with expecting a checkmark on legitimate calls). On average, Hiya did observe a 4.89% increase in call pickup rates overall while
35、 the checkmark was present. 5.4.2.3 Conclusions Further analysis is needed to determine if the numbers existing call profile (a “caller ID” name) or business industry was more effective than others. However, overall, this is taken to reinforce the positive impact a certified marker can potentially h
36、ave on pickup rates for verified calls. 5.4.3 Study #3: Warning Phrasing Test 5.4.3.1 Study Description Hiya has crafted 7 near-identical mockups of an incoming call screen. The only delta between the screen mockups was the presence of a warning phrase, expressing reasonable doubt about the legitima
37、cy of the caller. Study participants were shown this screen for 5 seconds, then asked a series of questions: 1. Would you answer this call? 2. Was this call from a trustworthy source? 3. Would you block this number from calling in the future? 4. Why do you think youre receiving this call? The follow
38、ing phrases were used, each shown to 400 unique participants (no overlap between phrases): Phone number only (baseline). “Fake Phone Number”, with phone number. “Possible Fraud“ with phone number. “Private Number“ with no phone number. “Unknown Caller“ with phone number. “Caller Not Verified“ with p
39、hone number. “Spoofed Number“ with phone number. 5.4.3.2 Results The results of the study are: Table 5.1: Results of Warning Phrasing Test Display Pickup Rate Block Rate User Trust Phone number only 30% 29% 46% “Private Number” (no phone number) 28% 43% 38%ATIS-1000081 10 Display Pickup Rate Block R
40、ate User Trust “Fake Phone Number” 21% 49% 30% “Possible Fraud” 11% 57% 20% “Unknown Caller” 24% 33% 42% “Caller Not Verified” 24% 39% 40% “Spoofed Number” 19% 51% 29% 5.4.3.3 Conclusions One main caveat is that these percentages should be validated against actual user behavior. A 33% block rate for
41、 unknown callers seems unexpectedly high. This should be verified via other means before concluding this reflects real-world behavior. However, while totals may not be actionable, the belief is the deltas between levels are valid. “Private Number” was included in this study only as an anecdotal comp
42、arison and is not a recommended display string. From this we can see minimal change in pickup rates, but a large increase in block rates. It was otherwise excluded from analysis. The main goal of the study is to find how different messaging affects users level of caution for an incoming call, while
43、separately measuring their likelihood to block the number in the future. The ideal message would greatly increase caution level, with minimal impact on block rates (as spoofed calls may impersonate legitimate numbers). Figure 5.2: Change in Pickup Rates, Change in User Trust, Change in Block Percent
44、ages, & Ratio Between the Two Overall, some variation was observed in the delta of user trust as it relates to the delta in block rates. Less aggressive message “Unknown Caller” has a lower block/trust ratio, but overall has negligible impact on both. Overall, all strings tested had significant impa
45、ct on the claimed block rate from users. Similar results between “Fake Phone Number” and “Spoofed Number” indicates user general understanding of the term “spoof”. ATIS-1000081 11 5.4.4 Study #4: Iconography Impact Test 5.4.4.1 Study Description Hiya selected two test strings “Possible Fraud” and “F
46、ake Number” and created eight mockups of an incoming call screen, four with each string. Each string was paired with one of three possible flagged icons: a red stop sign, a yellow triangle, and an “unknown person” icon. These were to be compared against the results of these strings with no icon, tes
47、ted in Study #2. Figure 5.3: Test images for “Possible Fraud” string Each participant (400 per mockup with no overlap) was asked the same questions as Study #2: 1. Would you answer this call? 2. Was this call from a trustworthy source? 3. Would you block this number from calling in the future? 4. Wh
48、y do you think youre receiving this call? 5.4.4.2 Results The results of this analysis are: Display Pickup Rate Block Rate User Trust “Possible Fraud” + no icon “Fake Number” + no icon 11% 21% 57% 49% 20% 30% “Possible Fraud” + stop sign “Fake Number” + stop sign 9% 17% 58% 51% 18% 25% “Possible Fra
49、ud” + warning sign “Fake Number” + warning sign 10% 17% 60% 54% 21% 25% “Possible Fraud” + unknown sign “Fake Number” + unknown sign 13% 18% 62% 50% 20% 30% 5.4.4.3 Conclusions Further analysis is recommended based on these results. Initial observations: ATIS-1000081 12 The addition of icons has relatively minor impact on block rates, beyond that from text alone. However, in all cases, block rates increased further. With the less severe “fake number” string, a supporting icon more strongly reduces pickup rates and overall perception of trustworthi
