NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Federal Communications Commission (FCC) North American Numbering Council (NANC) Nationwide Number Portability Working Group (NNP WG) Report on Nationwide Number Portability Final Report to the NANC July 28, 2020 1 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Table of Contents Executive Summary .................................................................................................................................. 3 Introduction and Background ................................................................................................................. 3 Description of NNP ................................................................................................................................ 4 Description of Internet Protocol Location Routing Number (IPLRN) .................................................... 5 Assumptions .............................................................................................................................................. 7 Effects of IPLRN ....................................................................................................................................... 8 A. Interconnection ............................................................................................................................... 8 B. Numbering ...................................................................................................................................... 9 C. Transport ....................................................................................................................................... 10 D. NPAC Dependencies..................................................................................................................... 13 F. End User Billing ........................................................................................................................... 16 G. Query Costs................................................................................................................................... 16 H. Consumer Expectations Regarding Toll Charges .......................................................................... 17 I. Nationwide 10-Digit Dialing ......................................................................................................... 18 J. State and Federal Tariffs for Retail and Wholesale Services ......................................................... 18 Recommended Path Forward to Implement IPLRN............................................................................ 19 Commercial Solutions as A Substitute For IPLRN .............................................................................. 26 IP Connectivity Arrangements .............................................................................................................. 27 Suggested Modifications/Considerations to The IPLRN NNP Model ................................................. 28 Minority Report Concerns and Response ............................................................................................. 28 Conclusion/Next Steps ............................................................................................................................ 30 APPENDIX A: ........................................................................................................................................ 31 Nationwide Number Portability Working Group Membership ............................................................. 31 APPENDIX B: ......................................................................................................................................... 33 Nationwide Number Portability Technical Subcommittee Membership ............................................... 33 Appendix C: Glossary............................................................................................................................ 34 Abbreviations:....................................................................................................................................... 34 Definition of Terms: ............................................................................................................................. 36 Appendix D: Minority Report............................................................................................................... 43 2 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Executive Summary In response to the Federal Communications Commission ( FCC ) Wireline Competition Bureau directive to the North American Numbering Council ( NANC ) to further analyze the Internet Protocol Local Routing Number ( IPLRN ) solution, we hereby submit the following considerations. " The greatest impacts will be to non-IP Service Providers for both cost and level of changes required to comply " Service Providers who may rely on transit providers to reach outside NPAs may not require network updates " Other Service Providers with legacy TDM networks may be impacted as internal software system and network updates to the network would likely need to take place " Consumer s will be impacted regarding changes to long distance calling costs and services; potential customer confusion if not all Service Providers implement NNP " Applicable Tariffs may need to be revised " The timeline for implementation should take into consideration all impacts In summary, with the goal of advancing progress towards nationwide number portability ( NNP ), there are several impacts related to the IPLRN solution noted within this document that should be carefully considered and seeking public comment as well as soliciting advice from other industry standards groups would be advantageous. Existing legacy TDM networks were not designed with IPLRN or more generally with NNP in mind. Thus, although the IPLRN proposed alternative generally relies upon established capabilities of TDM networks to originate NNP calls to IP networks, it is extraordinarily difficult to contemplate all unintended consequences that could result from such a proposal. Introduction and Background The NANC Nationwide Number Portability Issues Working Group (in the June 2018 report), defined Nationwide Number Portability as:  The ability of users of telecommunications services to retain existing telecommunications numbers without impairment of quality, reliability; or convenience when switching from one telecommunications carrier to another or when moving from one physical location to another. The LNP architecture relies upon the use of location routing numbers ( LRNs ) which identify the Service Provider s switch that serves the ported number. The Number Portability Administration Center (NPAC) feeds downstream databases to support queries associated with the dialed numbers. The query returns the LRN for the dialed number. The FCC currently limits the geographic scope of an LRN to a Local Access and Transport Area ( LATA ), thereby 3 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 restricting the ability of consumers to port a telephone number to a LATA other than its own. (The United States is covered by about 200 LATAs.) Description of NNP The FCC released the NNP Notice of Proposed Rulemaking/Notice of Inquiry ( Notice ), on October 26, 2017, which also sought comment on  how best to move toward complete nationwide number portability to promote competition between all Service Providers, regardless of size or type of service. 1 Specifically, the FCC requested input from industry stakeholders regarding prior work of the NANC, ATIS and other organizations. In addition to issuing the NNP NPRM, the FCC s Wireline Competition Bureau ( Bureau ) sent a letter to the Chairman of the NANC, dated December 7, 20172, directing its NNP WG to: Ï% Determine whether any of the four models discussed in the NNP Notice are preferable in terms of feasibility, cost, and adaptability to changing markets and technologies; Ï% Specify in detail the potential costs, benefits and barriers to implementing these proposals; Ï% Identify any likely consequences of these proposals for routing, interconnection, or public safety; Ï% Recommend next steps to advance full nationwide number portability; and make any other recommendations deemed necessary to achieve this goal The Bureau further directed the NANC to approve a written report of its findings on those issues, and to transmit that report to the Bureau. The NANC approved this report, which is publicly available at http://www.nanc-chair.org, at its May 29, 2018 meeting. On July 3, 2018, the Wireline Competition Bureau further directed3 the NANC to investigate the technical requirements necessary to support NNP and provide more detailed cost/benefit analysis of proposed lasting solutions to: 1. Provide an analysis of the technical requirements for adopting an Internet Protocol Local Routing Number (IPLRN) solution (previously referred to as NGLRN  Non-Geographic LRN), including which entities will need to make changes if this solution is adopted 2. Provide an analysis of the technical requirements for adopting a National Location Routing Number (NLRN) alternative, including which entities will need to make changes if this solution is adopted 1 Id.¶ 2; With publication of the NNP Notice in the Federal Register, the FCC received initial comments in the matter on December 27, 2017 and reply comments on January 26, 2018. 2 See, Letter from Kris Monteith, Chief, Wireline Competition Bureau, FCC, to North American Numbering Council Chair (Dec. 7, 2017), ( Wireline Bureau Letter ), http://www.nanc- chair.org/docs/mtg_docs/Dec17_NANC_Referral_NNP.pdf 3 See, http://nanc-chair.org/docs/mtg_docs/NNP-Ltr-frm-WCB-to-NANC-Chair-7-2018.pdf 4 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 3. Specify in detail the potential costs and benefits of the NLRN and IPLRN proposals, including which parties could bear which costs and reap which benefits; and 4. Recommend next steps the Commission and industry should take to achieve full nationwide number portability The initial interim report was requested for the December NANC meeting 2018. The final report was requested for the first NANC meeting in 2019. An extension was given (due to the Government Shutdown) moving the final report s due date to February 29, 2019. A second interim report was presented at the NANC s March 2019 meeting and the additional findings report was submitted to the NANC on May 13, 2019. An NNP recommendation was not reached by the NANC NNP Technical Committee. The Technical Committee recommended the impacts on interconnection, compensation, tariffs, and access charges be further investigated for the NLRN and IPLRN solutions. On December 16th, the Bureau directed the NANC to develop more specific recommendations regarding what the NANC described in the May 13, 2019, Report as the Internet Protocol Local Routing Number (IPLRN) solution. The bureau specifically directed the NANC to: 1. Analyze the likely effects of the IPLRN solution, including as to: a. Interconnection b. Carrier expenses relating to database dip costs and to transport costs; c. Consumer expectations regarding toll charges; and d. State and federal tariffs for retail and wholesale services 2. Recommend a path forward to implement the IPLRN solution, including specifically providing recommendations as to: a. The necessary series of steps, including the estimated time each step would take, b. in implementing the IPLRN solution; and c. The extent to which commercial solutions can serve as a substitute for the IPLRN solution for smaller carriers, including the cost of such solutions 3. Whether the IPLRN solution should be modified in light of any developments since the Report was issued and the conclusions reached with regard to #1 4. How to address the objections and concerns raised in the Minority Report accompanying the Report Description of Internet Protocol Location Routing Number (IPLRN) The IPLRN solution assumes to keep the current Local Number Portability architecture, including the role and responsibilities of the Number Portability Administration Center (NPAC). However, a new process would be implemented using IP-enabled switches or third-party IP networks that act as gateways. Service providers could use these gateways to assist in routing 5 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 NNP calls. IPLRN would not discriminate between wireless and wireline TNs, and the solution may work for both. The IPLRN proposed alternative has two main elements: Ï% One or more new non-geographic area codes and an administrative process to provide Service Providers with their own unique IPLRNs specifically and uniquely for NNP; Ï% VoIP nodes, functioning as IP Network Entry Points, that host IPLRNs and provide connectivity to Service Providers that port in NNP TNs. To enable NNP for a geographic telephone number ( TN ), the TN would be associated with a Service Provider specific IPLRN within the TNs current NPAC region. This is contrary to currently how a traditional geographic Service Provider specific LRN is associated to a TN within the same LATA. When a Service Provider acquires an IPLRN from the new administration function, the Service Provider would associate a Session Initiation Protocol (SIP) URI to that IPLRN, identifying the specific IP Network to be used for call processing on the VoIP network. Each IP Network entry point would deliver calls to one or more networks that terminate calls. When an LNP query is performed on the dialed TN, the IPLRN would be returned. Calls on the TDM network may query the local copy of the NPAC database and route based on the IPLRN s 3-digit area code to a VoIP network whether directly over a VoIP interconnect or over a TDM interconnect via a media gateway that would provide the TDM-to-IP protocol conversion that enables the call to continue in IP on a VoIP network. However, based on the routing of such 3-digit area code, each originating network would need to establish its own unique connection with a TDM interconnect via a media gateway that would provide the TDM-to-IP protocol conversion that enables the call to continue on an IP network. The IP network would query the full 6/10-digit IPLRN to obtain the terminating IP Network address, i.e., a SIP URI. Once on the IP Network, the call would be routed to the terminating network. This gateway functionality allows the TDM network to coexist and interoperate with the VoIP network. (See, Figure 1  IPLRN TDM to IP call flow, below). Figure 1  IPLRN TDM to IP call flow Calls that originate on a VoIP network may retrieve the 6/10-digit IPLRN from the local copy of the NPAC database and either receive the SIP URI in the same query or alternatively, may trigger on the IPLRN 3-digit area code to query a routing database with the full 6/10-digit 6 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 IPLRN to obtain the IP Network s SIP URI. The call would be routed to the correct terminating IP Network using the SIP URI. (See, Figure 2  IPLRN IP to IP call flow, below). Figure 2  IPLRN IP to IP call flow To summarize, the IPLRN solution uses an IP network consisting of VoIP nodes, which will terminate calls to NNP TNs. Service providers have multiple options as to how they update their routing (e.g., NPAC, commercial agreement, internal routing tables). However, there may be an option to update the SIP URI field via SOA and to retrieve IP routing information for each number via LSMS. In addition to SOA, there may be an opportunity to include IP information via the LERG"! Routing Guide or other databases. The IP Network may then route calls toward the terminating network based upon SIP URI and depending upon the terminating provider; the call may be terminated to a VoIP network or terminated to a media gateway that converts the protocol from IP to TDM. Thus, any time an NNP call is placed on the PSTN, it must route the call to an IP Network entry point so that the IP Network can route the call to the terminating network. For text messaging in an LNP environment, the NPAC could record locally cached SPIDs that are used rather than LRNs to allow routing to the correct recipient Service Provider. Assumptions 1. This report is informed by the 2 previous NANC NNP Working Group reports 2. We assume central offices which do not currently support LNP will not support NNP either 3. This report assumes that NNP calls are non-jurisdictional. 4. This report is focused on the IPLRN solution for NNP and the assumption remains that TDM end office switches are not able to support serving customers with NNP numbers. 5. All switches that are currently LNP-capable need to support the porting out of their customers. If the Service Provider is not able to provision an NNP subscriber, they would not be required to accept that customer's request. 6. All Service Providers must allow customers to port out their telephone number using NNP, except those exempted from porting out. 7. Originating Service Providers may bear the consequence for routing and transit to an NNP number. 8. All Call Query (ACQ) facilitates NNP and should be supported for all portable NPA- NXX. With ACQ, the originating Service Provider performs the number portability query 7 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 on all originating calls. Where ACQ is not technically feasible or where ACQ is not performed, the Service Provider network should route the NNP call on dialed digits to a downstream carrier to perform the query. Routing will continue to be based on 6 digits. 9. ACQ, including the exceptions that may be performed downstream, would require LSMS access to all NPAC regions. 10. NNP ports will be processed in the code holder s NPAC region. Thus, the NNP recipient Service Provider would require SOA access to all NPAC regions where providers plan to support such porting. 11. Wireless Service Providers who have the appropriate agreements for roaming may continue to use national roaming if they choose to do so. Permanent roaming is also expected to continue if Wireless Service Providers choose to continue to provide it. 12. If an IP call cannot be completed fully in IP and processes across a TDM interconnection or uses TDM transport in order to get to a NNP destination, it is assumed that the costs associated with doing so would be similar to what they are today, except for calls with the local routing option on IPLRN. For example, if a number was ported from New York to an IPLRN with a subscriber in California and the call at some point crosses a TDM interconnection or uses TDM transport, then the infrastructure cost of that call from the original LATA is potentially the equivalent to the cost currently for a long distance call from New York to California. 13. In alignment with the previous NANC NNP WG Technical Committee report, costs are stated as orders of magnitude using the following convention: " Small (S) - $10K-$90K " Medium (M) - $100-$999K " Large (L) - $1M-$9.9M " Extra-large (XL) - $10M+ Effects of IPLRN This section will analyze the likely effects of IPLRN as it relates to interconnection, numbering, carrier expenses related to database query costs and transport costs, consumer expectations regarding toll charges and state and federal tariffs for retail and wholesale services. A. Interconnection Agreements will be required to govern the IP connectivity between carriers. One hurdle that will be faced by IP-enabled providers in an IPLRN enabled environment is the general lack of desired terms of available IP Interconnection for smaller IP-enabled providers, as also mentioned in the May 2018 NANC NNP report. IPLRN could 8 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 facilitate direct IP interconnection with large players in the industry. This also could make it easier for non-IP providers to leverage existing interconnections for TDM-to-IP translation services. IPLRN enabled NNP can be facilitated via the Service Provider s own network or an existing transport provider that transports calls for the Service Provider (such as out of region calls). The creation of a new IPLRN prefix would be similar to the creation of a new area code, which is a process that is well established across different Service Provider types. The vast majority of providers should be able to leverage existing methodologies and commercial agreements to terminate traffic to these destinations (e.g., LCR, tandem transit, IXC). There will be no obligation to require carriers to support calls with IPLRNs that would terminate to their networks. Instead, Service Providers would have to demonstrate a capability of being able to support calls destined to IPLRN destinations not on their network. The IPLRN s sole purpose on a legacy switch is to identify that a number is NNP and therefore the call should egress the TDM network at the earliest opportunity. To assist with NNP routing via IPLRN, ACQ should be supported for all portable NPA-NNXs. ACQ should happen as early in the call path as possible in order to 1) know that the call is destined to an IPLRN, and where possible 2) obtain the URI s associated with the IPLRNs in IP networks. To perform ACQ within an NNP environment, access to porting records in all 7 NPAC regions would be required. With ACQ, the originating Service Provider typically performs the number portability query on all originating calls if the capability exists. Where ACQ is not technically capable in a Service Provider network, the Service Provider should route the NNP call on dialed digits to a downstream carrier to perform the query. If a non-IP provider performs the query to the local copy of the NPAC database, the IPLRN would indicate the call needs to be routed to a third-party provider. This third-party provider would also need to perform an additional query via a local copy of the NPAC to receive the voice URI value and properly terminate the call. The IP provider would transit that call to the IP network serving the subscriber. For Service Providers who do not subscribe to the NPAC URI fields in their LSMS streams, then the Fully Qualified Domain Name (FQDN)s may be obtained via the updated LERG records or alternate data source for that IPLRN. This presumes the network domain is the same as provisioned in the voice URI field of the NPAC. Similar companies offering PSTN hosting to VoIP providers today should be able to provide transport to the IP network indicated by the IPLRN. B. Numbering A single NPA-NXX per NNP Service Provider could be created and solely used for IPLRNs. The creation of a new IPLRN prefix would be similar to the creation of a new area code, which is a process that is well established across different Service Provider types. This allows for the industry to easily identify IPLRNs and may simplify switch programming for determining how to properly route NNP calls. Seeing an LRN with the IPLRN NPA would alert IP-enabled Service Providers to query a local copy of the NPAC 9 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 to receive the SIP URI and continue to route over IP. It is anticipated that most legacy switches can be programmed to recognize the NPA of an IPLRN and route to a designated IP provider to terminate over IP. The creation of new dedicated NPAs for IPLRNs would remove millions of numbers from possible assignment. The IPLRN may provide national coverage allowing for some VoIP and mobile providers to potentially forgo requesting multiple codes for IPLRNs in each serviceable LATA. IPLRNs would be managed and assigned by the North American Numbering Plan Administrator ( NANPA ) chosen by the FCC. Once the NANPA assigns an IPLRN to a Service Provider, that Service Provider has the responsibility to establish the IPLRN in the NPAC and LERG. Service providers should also add the assigned IPLRN to the LERG or appropriate data source to properly associate a routing FQDN. It is assumed that the FQDN shown for a given IPLRN will match the URI for the same IPLRN in NPAC. This will allow for alternative routing data in case URI data is not available within the local copy of the NPAC.4 C. Transport Interconnection This section attempts to address transport costs as the cost required to transport a call to the terminating network, which benefits the Service Provider to which the number is ported and not the Service Provider that originated the calls or subsequent Service Providers that transport the calls. IPLRN has a dependency on VoIP, which requires the use of IP and SIP for successful delivery of numbers that use an IPLRN. While IP has been deployed heavily in North American networks and interworking between networks is generally regarded to be a solved problem5, calling between networks require connectivity between the originating network (or that of its intermediary partner) and the destination network. From a physical network standpoint, IP relies on a nationwide fiber network that is physically interconnected. This fiber is offered through Service Providers that sell services, namely internet transit, point-to-point, and mesh networks. These Service Providers interconnect with one another and with content providers in carrier-neutral meet-me rooms around North America.6 The densest points of interconnection are in Los Angeles, the Bay Area, Chicago, Dallas, New York City, and Atlanta.7 They are serviced by thousands of Service Providers. There are three mechanisms of achieving this connectivity: Internet Transit, Network-to-Network Interface (NNI), or Exchange. 4 ATIS s Testbed Focus Group completed test calls via FQDN routing found in LERG test files. ATIS-I-0000067 contains the full summary. 5 NNI Profile, Joint Taskforce IP-NNI, SIP Forum 6 https://en.wikipedia.org/wiki/Meet-me_room 7 https://cloudscene.com/market/data-centers-in-united-states/all 10 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Internet Transit Video conferencing services such as like Zoom, Skype, and Google Meet have demonstrated the general efficacy of the internet for transport of Real Time Communications. At 80 kbit/s with overhead, the G711u (equivalent to TDM s PCMU) uses a fraction of the bandwidth required by major video calling platforms.8 The average price per megabit has fallen 90% in the past 10 years, with an average cost below $1.00 per Megabit per second.9 It is evident that the market-based transport services are generally more efficient than those offered under a tariff construct. This can be seen by the migration of consumers from tariffed services to market-based transport services. Rural Service Providers serving remote, rural areas are likely to face substantially higher costs and further investigation of internet transit costs for rural carriers is necessary. More importantly, Internet transit does not offer an equivalent service to dedicated TDM circuits, as call quality could be severely diminished as compared to that available today due to packet loss and jitter. The risk of failure or degradation increases as the number of  hops between the originating and destination network increases. While this can be mitigated through multi-homing (using multiple intermediary ISPs) that have implemented diverse network paths, public interconnection is still not an equivalent to current means of transport via TDM. Network-to-Network Interface (NNI) Ethernet NNIs in some respects can be characterized as the IP equivalent of TDM interconnection. They involve physically interconnecting two networks -- typically via fiber. This interconnection can happen at the originating network, terminating network, or some mutually agreed upon Point of Interconnection (POI) (i.e., meet-me room). Once the two networks are physically connected, Ethernet is established, and interworking can be established in a manner similar to the Internet Transit case. When using a meet-me rooms as a POI, a fiber cross-connect supporting up to 100 Gb/s) is typically $250-400/month.10 However, in the case where two networks do not share a POI, there will be additional costs associated with bringing transport to these locations. One challenge with NNI interconnection is which operators bear what costs to interconnect. Rural and other Service Providers are concerned that if they are made to bear the costs of interconnecting at distant points from their service area  an arrangement that upends existing practices as these carriers typically exchange voice traffic at or near their  network edges  they will be unduly burdened with substantial transport costs that they do not bear today. These costs will, for the first time ever, be 8 https://www.cisco.com/c/en/us/support/docs/voice/voice-quality/7934-bwidth-consume.html https://support.zoom.us/hc/en-us/articles/201362023-System-requirements-for-Windows-macOS-and-Linux 9 https://www.ncta.com/whats-new/the-price-per-megabit-per-second-has-gone-down-90-percent 10 https://www.datacenterhawk.com/blog/connectivity-perspectives-low-cost-amenity-or-high-margin-business 11 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 foisted on Rural Service Providers and their small customer bases and will then need to be applied on top of the already higher costs of serving a rural area. Exchange Point An exchange point is the physical infrastructure by which carriers can exchange traffic between their networks. Generally, these are located at regional data interconnect points, also known as carrier-hotels. It is possible that exchange points can be implemented to deal with the costs associated with establishing NNIs between every network in the United States. This is a concept commonly used to exchange internet traffic. Exchange points provide a single physical location conveniently located to service providers that allow them to exchange traffic with one another. Exchange points offer the benefits of NNIs without the cost overhead costs associated with interconnecting with every service provider. Most ISPs, including most RLECs use similar exchanges for exchanging internet traffic. It is possible that these facilities can be repurposed to serve this use case. Additional Interconnection Considerations Although the above mechanisms for interconnection address current commercially available methodologies, the current regulatory construct for interconnection must also be addressed. Thus, the IPLRN proposal introduces issues around interconnection that should properly be addressed in the FCC Technology Transitions proceeding11 or other appropriate regulatory proceeding where the regulatory obstacles may be considered. For example, costs to Service Providers may be reduced  and IP voice interconnection with Service Providers can be made possible  by the adoption of rules that appropriately allocate the costs associated with the NNP transport responsibilities. Additionally, IPLRN and more generally an NNP requirement further implicates POI location obligations associated with calls that originate on TDM networks. Without addressing such regulatory policy changes, the voluntary nature of negotiated commercial agreements is likely the only path for IPLRN and NNP in general that would avoid conflict with the existing interconnection policy. The issue of how to facilitate ubiquitous IP Interconnection for Real Time Voice Communications using NANP numbering has been well documented. IP interconnection relies fundamentally on telephone number to URI translations. The ATIS/SIP Forum IP-NNI Task Force delivered a report entitled ATIS-1000062 IP Interconnection Routing; however, consensus on a single registry architecture was not achieved.12 Should there be a future opportunity to technically access IP interconnection routing as networks evolve and regulatory policies change, IPLRN should be considered. 11 GN Docket No. 13-5 12 https://www.sipforum.org/download/joint-atissip-forum-technical-report-ip-interconnection-routing-atis- 1000062-sipforum_twg-6/?wpdmdl=2780 12 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 D. NPAC Dependencies The NNP proposal below based on an IPLRN does not require changes to the NPAC SMS data model or to the local system interfaces (i.e., SOA or LSMS). The expected changes are focused on configuration and business processes at the SOA and LSMS edge which are local to Service Providers as well as internal business logic updates within the NPAC regarding current edits performed on the LRN attribute and possibly new reporting requirements. The NPAC SMS would need to update its edits for the LRN when the ported TN record (subscription version) is created or modified. When an IPLRN is detected by the NPA prefix, the LRN edit constraining ports to be intra-LATA will not be performed. For all other NPAs, the LRN edit constraining ports to be intra-LATA will remain as-is. It is assumed that the subscription version will be maintained in the Region the number is assigned for identification purposes. That is, subsequent ports would be easily identified given the telephone number is uniquely assigned to a known location which is the code holder s NPAC region. There would be two general impacts to the Service Providers and others in the NPAC SMS ecosystem given this NNP architecture: 1. ACQ would require that the originating switch when digits are dialed will have access in its Number Portability Data Base (NPDB) for all LSMS records across the U.S. given the dialed number may terminate outside the local NPAC SMS Region.13 2. Service Providers that plan to port an NNP number into their location would need to have their SOA System connected to the NPAC SMS Region or select the applicable region via the Low Tech Interface (LTI) for which the new subscriber s number is geographically assigned (i.e., the code holder region).14 Currently, Service Providers that port local numbers are connected to the NPAC SMS Region where that number is assigned. In the NNP model, a number that is geographically assigned, for example, to the Northeast Region, can be updated to reflect a port to a location for which facilities are on the west coast. If the New Service Provider (NSP) only provides facilities in a territory on the West Coast currently, they would not need to have a SOA connection to the Northeast NPAC SMS Region for local number porting. With NNP, any Service Provider offering NNP for any subscriber would require a SOA that supports all NPAC regions. 13 Today all national carriers receive downloads from all the NPAC SMS Regions. In the future, carriers that have presence in a single or limited number of Regions would need to have the ported data for all of the NPAC SMS Regions. In other words, their NPDB would need to be provisioned with all of the NPAC SMS LSMS regional download data. 14 Furthermore, NNP Service Providers would need to provision (i.e., create) an LRN with their assigned IPLRN value in all regions where it would be applicable, which is likely to include all the regions. Once created, their IPLRN may be assigned to as many TN records as required based on the subscribers requesting NNP. 13 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Please see Figures A and B for the change in the LSMS and SOA connection management required to support ACQ and NNP provisioning. Figure A  Current Local Number Portability Figure B - Nationwide Number Portability 14 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 E. 9-1-1 Connectivity Public safety (E9-1-1 or NG 9-1-1) is a concern that must be considered in implementing NNP with IPLRN using IP-enabled switches or third-party IP networks that act as gateways. Accurate originating location information of all E9-1-1 calls is vital to providing emergency services in a timely manner. 9-1-1 calls originating from NNP TNs may utilize the p-ANI solution to provide accurate location information for the originating TN. NNP calls to 9-1-1 will likely require p-ANI services to route to the correct PSAP. This may not be feasible in some wireline TDM networks but could potentially be offered by third parties. Calls to 9-1-1 initiated by NNP TNs could use the existing p-ANI solutions deployed for wireless and VoIP Service Providers. Today, there are multiple vendors who provide a p-ANI-based solution via commercial agreements. Notably, current implementations for Wireless and VoIP providers (e.g., p-ANI) used to route 9-1-1 calls today can be and are used for NNP. 9-1-1 Costs Commercial agreements /p-ANI solutions will have their own cost. Service providers choosing to offer NNP will likely incur expenses associated with the negotiation of interconnection with third parties to provide a POI in the donor LATA. Service providers choosing to offer NNP may also have to pay for upgrades to billing systems, number inventory systems, caring for  out of rate center numbers, as well as 9-1-1 solutions. For example, Service Providers with traditional fixed-line connections to the local PSAP, would need to support p-ANIs or use third-party solutions. 9-1-1 (p-ANI) IPLRN alternative costs For originating 9-1-1 calls, the Service Provider would need to consider the following capabilities and charges: " Provisioning and data services: o Collection and maintenance of Geographic Information System (GIS) based 9-1-1 Authority jurisdiction data to include roads, structures, and emergency response boundaries o Establishment or use of existing p-ANI records per jurisdictional boundary to support a routing path through legacy 9-1-1 selective routers to a specific PSAPs o Establishment or use of dedicated 9-1-1 trunking to the jurisdiction s 9-1-1 Service Provider to transport 9-1-1 traffic from the p-ANI contracted commercial provider to the PSAP o Establishment or use of dedicated data services for real time delivery of location data at the time of the emergency call o Customer record preparation, validation and storage services for pre-call validation, which may include GIS data (latitude/longitude) confirmation services 15 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 o Staffing for error research and clearance " Emergency Call Processing o Compliant, dedicated trunking between originating carrier and contracted commercial provider. o Real time location determination services and conversion to GIS data if not available prior to the emergency call. This is only needed if the end user is not in a fixed location (e.g., a soft-phone or over-the-top VoIP application). o Staffing and operation of a dedicated call center structured to manage emergency calls not properly provisioned prior to an emergency call. Service pricing varies by the size of the originating carrier and the size of the jurisdictional footprint the carrier intends to cover. Typical agreements would include a non-recurring set up charge to establish services, and a monthly charge per customer record for validation and storage that would be volume based. F. End User Billing It should be assumed that local calling would remain under the same regulatory jurisdictions as it is currently, and the IPLRN solution offering to the calling party would likely be set based on the originating provider s agreement with their customers. It can also be assumed that for a majority of calls routing over IP, the VoIP rate would be in accordance with the originating provider s agreement with their customer, and the originating provider s agreement with the interconnecting partners and may vary from the local tariffed rate.15 Given these assumptions, the calling party may experience a change in their billing when routing over IPLRNs rather than local LRNs. G. Query Costs Service Provider expenses relating to database query costs and to transport costs As indicated in the assumptions above it is expected that IPLRN would require LNP queries for all calls (ACQ). Unless there is an exemption for certain geographic areas or network operators, NNP allows for numbers to be ported from locations where LNP porting does not currently exist. This would require numbers that are currently excluded from the need to perform LNP queries to potentially become eligible for porting. Thus, this would drive queries where local competition does not exist and that otherwise would not require LNP queries. Currently, there are 6,147 Geographic NPA NXX s that are identified as codes that are not subject to porting; these are in addition to the NXXs associated with providers that have obtained waivers for intermodal porting. N-1 is the current backstop on an unqueried call LNP query policy.16 For NNP, it may be most efficient to determine the NNP nature of calls as close to the point of origination to 15 See: https://prodnet.www.neca.org/publicationsdocs/wwpdf/6911google.pdf 16 See FCC 18-95 16 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 prevent unnecessary routing. This query policy would shift the volume and costs of LNP queries from them being performed by both the originating Local Exchange Carrier (LEC) for local calls and Interexchange carriers for long distance calls to the originating Service Provider for both local and long-distance calls. Some Service Providers may already perform ACQ on all originating calls as they do not differentiate on jurisdiction (routing local vs. routing long distance via IXC). The cost allocation for ACQ by the originating Service Provider will need to be addressed as is reflected in previous reports. Although the benefit of ACQ resides with the Service Provider that acquires customers using IPLRN and benefits from NNP capability, the originating Service Providers under ACQ would be burdened with performing originating queries and potentially the transport of calls to the terminating network. In the event that ACQ is not performed and calls are subject to default routing (i.e., calls that route to the Service Provider originally allocated the numbering resource without being queried), cost allocation must also be addressed. As explained in the minority report of the previous working group s effort, the overall economic impact of ACQ on legacy network Service Providers is not well understood, especially the costs of equipment upgrade to enable a localized cache of the full NPAC. H. Consumer Expectations Regarding Toll Charges There is a difference in how customers are charged for calls to TNs in geographically distant locations, dependent on their Service Provider s regulatory construct, for example: " Wireline  Local and toll charges, possibly some packages " Wireless  Package billing " VoIP  Package billing As a result, some customers may be more aware of toll charges than other customers. The expectation: This example is for where a customer is aware of toll charges  Customer A, who dials a TN to their neighbor, customer B, may assume it is a local call; however, if NNP is implemented, their neighbor may have moved to a geographically distant location. From an end user billing perspective, customer A expects that the call will have no additional charge because they dialed a local TN to reach customer B. The reality: The infrastructure used by customer A s Service Provider to get that call to customer B via their IP SP may vary from the infrastructure used when customer B was previously physically located in the same geography as customer A. However, customer A is unaware of that variance, and may not even know that customer B has moved to a geographically distant location. Customer B s IP-based SP may require customer B to register with a geographically based SBC for other reasons, yet customer A and their SP have no insight to this information. The regulation: 17 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Future regulatory action could make a change related to local and toll charge applications. IP telephony does not have a long-haul carriage distinction as is present in current TDM SS7 geographic jurisdiction-based call rating. IP SPs may base their charges to their customers on the same structure as their IP commercial interconnection agreements, or some other package-based charging. I. Nationwide 10-Digit Dialing Dialing plan consistency (e.g., national 1+10-digit dialing) may be needed. For example, variations exist across the country with how calls can/should be dialed, i.e., 1+10-digits, 10-digits, and/or 7-digits. These are often related to intelligence in the dialed number relative to routing. For example, local calls originating and terminating within the same NPA, if only one NPA today serves the area, are usually dialed on a 7-digit basis. Areas where NPA overlays have occurred are dialed as 1+10-digits or only 10-digits depending on the dial plan approved by the state. NNP impacts on the varying dialing plans need to be assessed. 10-digit dialing may not be required where switches are capable of amending the dialed number with the 3-digits of the default NPA associated with the 7-digit dialed digits. This would facilitate the 10-digits required for ACQ. However, it is not clear of the TDM switch types that may allow for such switch logic programing if ACQ is a capability of the switch. Amending dial digits to facilitate ACQ may have implications for call authentication efforts. Depending upon the consistency of the application of call jurisdiction, i.e., local vs toll, in areas where NNP is available, consumer confusion may be a factor where 7-digit dialing for local calls exist. This may materialize in several ways. Where Service Providers vary their application of call jurisdiction, consumers may become confused from provider to provider as to what calls may be dialed with 7-digits (local) vs 10-digits (toll). Additionally, consumers that are used to dialing 7-digits for local calls may become confused when a 7-digit dialed NNP call is toll or a local call that requires 10-digits is local. Although the 10-digit dialing requirement in most US NPAs will be necessary to implement the 988-suicide hotline and may address much of this issue across the country and to resolve any difficulties with call authentication, it may make sense for the nation to adopt 10-digit dialing nationwide. J. State and Federal Tariffs for Retail and Wholesale Services In the current environment, services that Service Providers offer are filed in tariffs in the state jurisdictions where applicable. These rely on the ability to determine the general geographic location, such as the LATA, of the initiating and/or called party, particularly for distinguishing between local and toll calls. In an IPLRN environment, where the initiating party may not know whether a call being placed is local or to a geographically ported number, Service Providers that offer these tariffed services would need to either replace or remove those services or revise definitions. The amount of time required to modify, file, and have tariffs approved at the state level vary by state; therefore, a transitional period may be necessary as carriers move to the IPLRN environment. 18 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 " Federal tariffs filed with the FCC, by definition, cover interstate services. Calls made in an IPLRN environment that are interstate in nature could be conceivably covered by existing tariffs. Recommended Path Forward to Implement IPLRN The following section provides recommended steps and a timeline to implement IPLRN. The recommendation takes into consideration the type of carrier, switching equipment and capabilities. The following chart reflects IPLRN network changes required for NNP implementation, who benefits, and who incurs the associated costs, and the order of magnitude of those costs: Switch Telephony Switch NNP Changes Who Magnitude Who Function Type Required incurs S/M/L/XL Benefits Cost Originating Routing Legacy ACQ3 if All orig M-L per NNP SPs Wireline feasible or SPs who switch; (LD) downstream do not depending commercial have ACQ on IP arrangement; already; capability transport costs all orig and/or associated with SPs; all commercial reaching the IP orig SPs agreements; network; S per switch adding IPLRN to all switch translations Originating Routing Legacy ACQ3 if All orig L per NNP SPs Wireline feasible or SPs who switch; (Local) downstream do not S per commercial have ACQ switch; M arrangement; already; per switch adding IPLRN all orig depending to all switch SPs; all upon IP translations; orig SPs capability or commercial ACQ requires agreement; LSMS data for M per all NPAC switch regions; 19 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Switch Telephony Switch NNP Changes Who Magnitude Who Function Type Required incurs S/M/L/XL Benefits Cost trunking between TDM and IP switches Originating Routing Legacy ACQ3 if All orig L per NNP SPs Wireline feasible or SPs who switch; (2-PIC) downstream do not depending commercial have ACQ on IP arrangement; already; capability transport costs all orig and/or associated with SPs; all commercial reaching the IP orig SPs agreements; network; S per switch adding IPLRN to all switch translations; CIC routing based on LRN; ACQ requires LSMS data for all NPAC regions Originating Routing VoIP ACQ3 if not All orig M per NNP SPs already in use; SPs who network do not Requires have ACQ LSMS data for already all NPAC regions Originating Routing Mobile ACQ3 if not All orig M per NNP SPs already in use; SPs who network do not segment Requires have ACQ LSMS data for already all NPAC regions 20 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Switch Telephony Switch NNP Changes Who Magnitude Who Function Type Required incurs S/M/L/XL Benefits Cost Originating Routing LNPA Remove LATA LNPA S for the NNP SPs edit prohibiting LNPA NNP Originating Rating Legacy LRN based Orig SPs L per NNP SPs; Wireline rating2 with LD network as ; Orig SPs (LD plans calls that might Option) would were recover enhance previously some costs rating for rated as for their NNP calls local now NNP LD need to be calls via the rated as LD rate plan and Form 4994 reporting Originating Rating Legacy N/A N/A N/A NNP SPs; Wireline (Local Option) Originating Rating Legacy LRN based Orig SPs XL per NNP SPs; Wireline rating; with LD network for Orig SPs (2-PIC plans for rating and might Option) rating of Form 4994 recover all calls reporting some costs for their NNP LD calls via the rate plan Originating Rating VoIP LRN based All Orig L per NNP SPs rating if LD SPs who network for rate plan do not rating currently changes do this 21 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Switch Telephony Switch NNP Changes Who Magnitude Who Function Type Required incurs S/M/L/XL Benefits Cost Originating Billing All types No Change N/A N/A NNP SPs; Originating switch only on NNP LD calls Transit Routing RBOC Routing Transit M per NNP SPs; Tandem changes to Carriers tandem Originating egress the switch if switch only TDM Network RBOC on NNP via IP. If not tandem is LD calls supported, IP- responsible capable tandem for TDM to Service IP Providers can translation. be leveraged to No change if translate TDM IXC has the to IP. An obligation to additional support IP query for NNP calls. calls would be required to identify the destination SIP URI as well as LSMS access to all NPAC regions Transit Routing VoIP A query for N/A M per N/A Transit NNP calls network. would be required to identify the destination SIP URI as well as 22 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Switch Telephony Switch NNP Changes Who Magnitude Who Function Type Required incurs S/M/L/XL Benefits Cost LSMS access to all NPAC regions. Routing would need to be modified to support sending calls via this method including codec negotiation or other SIP required attributes. Transit Routing IXC LD A query for N/A M per NNP SPs; Tandem NNP calls network. Originating would be switch only required to on NNP identify the LD calls destination SIP URI as well as LSMS access to all NPAC regions. Transit Routing MSC N/A N/A N/A N/A Gateway Transit Rating RBOC The ability to RBOC L per NNP Tandem rate calls Tandem network. Service routing on Providers. IPLRNs. Transit Rating VoIP N/A N/A N/A N/A Transit 23 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Switch Telephony Switch NNP Changes Who Magnitude Who Function Type Required incurs S/M/L/XL Benefits Cost Transit Rating IXC LD The ability to IXC LD L per NNP Tandem rate calls Tandem network Service routing on Providers. IPLRNs. Transit Rating MSC N/A N/A N/A N/A Gateway Transit Billing RBOC N/A N/A N/A N/A Tandem Transit Billing VoIP N/A N/A N/A N/A Transit Transit Billing IXC LD N/A N/A N/A N/A Tandem Transit Billing MSC N/A N/A N/A N/A Gateway Terminating Provisioning Legacy Assumed not N/A N/A N/A Wireline possible Terminating Provisioning VoIP SOA support NNP SPs S for SOA NNP SPs for the IPLRN change; and access to M for TN all NPAC admin regions changes Terminating Provisioning Mobile SOA support NNP SPs S for SOA NNP SPs for the IPLRN change; and access to M for TN all NPAC admin regions changes 24 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Switch Telephony Switch NNP Changes Who Magnitude Who Function Type Required incurs S/M/L/XL Benefits Cost Terminating Provisioning Mobile No Change N/A N/A N/A permanent roading Terminating Routing & Legacy Assumed not N/A N/A N/A Termination Wireline possible Terminating Routing & VoIP N/A N/A N/A N/A Termination Terminating Routing & Mobile N/A N/A N/A N/A Termination Terminating Rating Legacy Assumed not Term SP M per NNP SP; Wireline possible if (Code network Term SP if NNP TN not Holder1) billing for provisionable; onward Support rating routing for onward routing to NNP provider Terminating Rating VoIP Support rating Term SP M per NNP SP: for onward (Code network Term SP if routing to NNP Holder1) billing for provider onward routing Terminating Rating Mobile Support rating Term SP M per NNP SP; for onward (Code network Term SP if routing to NNP Holder1) billing for provider onward routing Terminating Billing & Legacy Support billing Term SP M per NNP SP; Settlement Wireline upstream SP (Code network Term SP if not using ACQ Holder1 ) billing for 25 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Switch Telephony Switch NNP Changes Who Magnitude Who Function Type Required incurs S/M/L/XL Benefits Cost for NP query onward and NNP routing onward routing Terminating Billing & VoIP Support billing Term SP M per Term SP if Settlement upstream SP (Code network billing for not using ACQ Holder1) onward for NP query routing and NNP onward routing Terminating Billing & Mobile Support billing Term SP M per Term SP if Settlement upstream SP (Code network billing for not using ACQ Holder1) onward for NP query routing and NNP onward routing Commercial Solutions as A Substitute For IPLRN This section details how commercial solutions can serve as a substitute for rural carriers to implement NNP. The use of commercial agreements by a provider is considered by both the wireless industry and by the assessment of NNP options conducted by ATIS, as an interim solution. Twenty-six (26) various organizations, notably LNPA WG, ATIS, CCA/CTIA and the NANC FON WG, have all previously identified and evaluated the use of commercial agreements to accommodate a Service Provider s ability to provide NNP for its end users. The commercial agreement solution, as stated in the 2016 ATIS NNP Technical Report17, includes the use of third-party facilities to provide a POI in the donor LATA and to deliver traffic from that POI to the network of the recipient provider in a distant LATA. 17 https://www.atis.org/01_strat_init/nnp/docs/ATIS-1000071.pdf. 26 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 IP Connectivity Arrangements SIP connection A lack of IP connectivity options also may limit effective use of commercial agreements by certain kinds of providers and in certain areas, such as VoIP providers that need to find a third- party provider to convert calls from IP to TDM for purposes of interconnection and traffic exchange. IP connectivity agreements directly with ILECs may be unavailable due to the lack of IP capability within some ILEC networks. In some commercial agreements, there may also be provisions that prevent the efficient and economic interconnection with other Service Providers, such as terms that stipulate that the non-national or non-facilities-based Service Provider may not pursue IP interconnection with originating networks, and that any traffic destined for that Service Provider must route through its Service Provider partner's network. In addition, some existing interconnection agreements ( ICAs ) may contain language which restricts porting to within the rate center boundaries. Numbering & Routing " There are no changes to existing routing requirements that would prevent NNP. " There are no changes to numbering (administration & guidelines) with the use of commercial agreements. " Although not a full barrier to implementation, the use of third parties to provide a POI in the donor LATA and to deliver traffic from that POI to the network of the recipient can increase the complexity of the routing, sometimes resulting in confusion to Service Providers when troubleshooting issues with multiple Service Providers involved. However, such confusion may be reduced by standardizing the processes that facilitate efficient troubleshooting. " N11 dialing could require changes by the provider to reflect the geographic location, not basing the translation on the NPA NXX. " Service providers local calling scopes could require changes as a result of NNP. Costs " Estimated costs for 3rd party. Service providers choosing to offer NNP would likely incur expenses associated with the negotiation of interconnection with third parties to provide a POI. Service providers choosing to offer NNP may also have to pay for upgrades to billing systems, number inventory systems, caring for  out of rate center numbers, as well as 9-1-1 solutions. For example, Service Providers with traditional fixed-line connections to the local PSAP would need to support p- ANIs or use third-party solutions. " IP Connectivity estimated costs 27 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 o IP connectivity pricing varies by carrier location, and there may be additional requirements for leased facilities where connectivity is not present. Typical agreements would include a non-recurring set up charge for installation and a monthly reoccurring charge for maintaining the facilities and connection. " Service provider systems estimated costs " Upgrades to a provider s internal systems (e.g., billing, number management, etc.) would vary. Factors include a carrier s internal versus external development, level of development (e.g., code or patch, etc). " Service provider 9-1-1 (p-ANI) solution costs o In a commercial agreement for originating 9-1-1 calls, the Service Provider would need to consider the capabilities and charges. o Service pricing varies by the size of the originating carrier and the size of the jurisdictional footprint the carrier intends to cover. Typical agreements would include a non-recurring set up charge to establish services, and a monthly charge per customer record for validation and storage and would be volume based. Suggested Modifications/Considerations to The IPLRN NNP Model The current NNP WG was asked to consider whether the IPLRN solution should be modified in light of any developments since the June 2018 Report was issued and the conclusions reached with regard to #1; #1 Analyze the likely effects of the IPLRN solution, including as to: a. Interconnection; b. Carrier expenses relating to database dip costs and to transport costs; c. Consumer expectations regarding toll charges; and d. State and federal tariffs for retail and wholesale services. The NNP WG has carried forward many assumptions from previous NNP WG efforts. It is unlikely that the IPLRN model would need to be modified or reconsidered unless these assumptions change or policy decisions are made regarding traffic jurisdiction, intercarrier compensation, POI location and interconnection requirements. Minority Report Concerns and Response The minority report18 identified valid issues associated with the implementation of NNP. These elements are included in this report. 18 See Appendix D 28 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 The issues, as identified in the Minority Report response to the NNP Technical Sub-Committee report that must be addressed by the Commission are Intercarrier Compensation, IP Interconnection, and industry routing database accommodations to support proposed interim and long-term solutions. The very nature of NNP breaks the association of the TN to a specific geographic area on which many policies in U.S communications are based. These impacts are not unique to any one particular NNP technical alternative, be it IPLRN or the NGLRN or NLRN approaches explored in previous reports. Before an NNP solution is implemented, these issues will need to be addressed, whether in the Technologies Transition docket or in another regulatory proceeding. Intercarrier Compensation Current FCC rules on Intercarrier Compensation, CC Docket No. 01-92, favor TDM interconnection - Intercarrier Access reform would have to be addressed to incentivize IP interconnection. The Commission has appropriately declined to classify Interconnected VoIP as a Title II service and has used its plenary numbering authority under Section 252(e) 1 of the Act to expand 9-1-1 and LNP obligations to VoIP Service Providers. Originating access reform remains to be addressed and should be resolved to avoid the complication by an NNP mandate and implementation prior to such reform. This becomes more challenging as originating access would be difficult to expand to include the addition of transport outside of the LATA and therefore should be eliminated. If the issues around intercarrier compensation are not resolved, then this would further challenge the legacy network operator s capability to allocate appropriate charges associated with existing and additional costs and may divert funds that could otherwise be used for transitioning to IP. The IPLRN proposal has been significantly modified from its original NGLRN form to remove the NGGW function. While it is assumed, that this will result in fewer points of interconnect due to the unresolved regulatory construct issues it may result with IP Gateways and/or transport in/to potentially every rate center. Although the Commission s policy has been to incent the industry away from rate centers and LATAs, as the Intercarrier Compensation reform effort has proved, there is still significant cost pressures against that effort. As this relies upon federal policy, the FCC s Technology Transition proceeding or other appropriate regulatory proceedings appear to be the appropriate way to address these issues prior to an NNP mandate. Other Considerations This has raised the question in the NNP WG of whether it is technically feasible to permit some elements and Service Providers of the industry to enable NNP and allow others a delay or optional implementations such as areas where there is no demand for porting. Pursuant to the minority report, the combination of STIR/SHAKEN, IVC, 988, NNP and all IP Interconnection should be addressed from a goal-based policy approach prior to an NNP mandate. 29 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Alternatives that require changes to TDM-based networks divert resources and are a distraction from addressing the broader issues of Intercarrier Compensation and Technology Transition. Any interim regulatory focus should concentrate on the dependencies that would place the technological options on equal footing, including encouraging the existing commercial agreements alternative discussed in previous reports. Conclusion/Next Steps The IPLRN alternative provides an opt-in NNP solution that would allow non-IP enabled service providers to continue migration to IP technology. The NNP Issues Working Group performed an in-depth analysis to determine the effects of IPLRN on interconnection, carrier expenses, consumer expectations and tariffs. Carrier expenses related to database queries and transport costs will vary greatly based on the type of Service Provider. The group determined that non-IP Service Providers will be greatly impacted in both costs and the level of changes required to support NNP. Service Providers with legacy TDM networks will incur the highest costs to support NNP via an IPLRN solution due to the need to update networks, internal software systems and entering into commercial agreements with an IP provider to transport NNP calls. The Working Group recommends the impacts on access charges be further investigated for the NNP alternatives. Service Providers that offer long distance calling services at a cost to consumers may need to educate their customers or change their service offerings. Some Service Providers may elect to not offer NNP which may cause consumer confusion. Applicable tariffs would be impacted by any NNP solution implemented and may need to be revised or redefined to support NNP. The impacts to each Service Provider to implement an IPLRN solution will vary greatly based upon the type of service provided, the age of existing network elements and internal system development to upgrade billing and numbering software. For routing of NNP calls to function correctly, changes required to networks and software for an IPLRN implementation must be coordinated across all Service Providers. Therefore, the timeline for implementation must allow for the various changes required by different service providers. Existing legacy TDM networks were not designed with IPLRN or more generally with NNP in mind. Thus, although the IPLRN proposed alternative generally relies upon established capabilities of TDM networks to originate NNP calls to IP networks, it is extraordinarily difficult to contemplate all unintended consequences that could result from such a proposal. Although some evaluations could be more thoroughly evaluated through standards development, some unintended consequences may not be fully understood until implementation. The FCC should seek comment on the impacts and costs identified in this report in implementing an IPLRN solution to support NNP. Additionally, the related techniques described in this report 30 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 should be reviewed by the appropriate subject matter experts in the industry forums that govern changes for those products. Specifically, the Common Interest Group for Rating and Routing (CIGRR) for LERG and the informal LNP Working Group (previously the NANC TOSC) for NPAC SMS. APPENDIX A: Nationwide Number Portability Working Group Membership Chairs: USConnect Bridget Alexander White, Staff Director, Business Development CenturyLink Philip Linse, Director for Public Policy Members: Alliance for Telecommunications Industry Solutions Jackie Wohlgemuth, Senior Manager of Global Standards Development AT&T Services, Inc. Teresa Patton, Principal -Technology Solutions Manager Bandwidth Inc. Robert Brezina, Director, Number Management Charter Communications, Inc. Glenn Clepper, Director  Regulatory Comcast Corporation Beau Jordan, Director, Compliance Legal/Regulatory Competitive Carrier Association Alexi Maltas, SVP & General Counsel Cox Communications Jennifer Hutton, Bill Application Process and Support Specialist Inteliquent 31 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Bryan Bethea, Senior Director National Association of Regulatory Utility Commissioners Rebecca Beaton, Infrastructure Manager, Washington Utilities and Transportation Commission NTCA  The Rural Broadband Association Brian Ford, Director of Industry Affairs Peerless Network, Inc. Julie Oost, Vice President of Regulatory Affairs and Contracts Public Service Commission of Nebraska Cullen Robbins, Director of Communications SIP Forum Richard Shockey, Chairman of the Board of Directors T-Mobile USA, Inc. Rosemary Leist, Senior Numbering Policy Manager, State Government Affairs, Legal Affairs Telnyx Inc. David Casem, CEO TDS Telecommunications LLC Paul Nejedlo, Senior Administrator  Number Management Verizon Mark Desterdick, Distinguished Member of Technical Staff Non-Voting Members: iconectiv, LLC Chris Drake, Chief Technology Officer Somos, Inc. Mary Retka, Senior Director for Industry Relations 32 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 APPENDIX B: Nationwide Number Portability Technical Subcommittee Membership Chair: Somos Mary Retka, Vice President for Industry Relations Members: AT&T Services, Inc. Teresa Patton, Principal, Technology Solutions Manager CenturyLink Philip Linse, Director for Public Policy Charter Communications, Inc. Glenn Clepper, Director - Telephone Regulatory Comcast Corporation Beau Jordan, Director, Compliance Legal/Regulatory Henning Schulzrinne, Professor Telcordia Technologies, Inc. dba iconectiv Chris Drake, Chief Technology Officer T-Mobile USA, Inc. Rosemary Leist, Sr. Numbering Policy Manager Telnyx LLC David Casem, CEO 33 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Appendix C: Glossary Abbreviations: ACQ All Call Query ATIS Alliance for Telecommunications Industry Solutions CCA Competitive Carrier Association CdPN Called Party Number C4 Class 4 Switch C5 Class 5 Switch CSCF Call Session Controller Function I-CSCF Interrogating - Call Session Controller Function P-CSCF Proxy - Call Session Controller Function S-CSCF Serving - Call Session Controller Function CTIA CTIA  The Wireless Association DNS Domain Name System ENUM Electronic Numbering FCC Federal Communication Commission FQDN Fully Qualified Domain Name GIS Geographic Information System HSS Home subscriber server IP Internet Protocol IPLRN Internet Protocol Location Routing Number IP-NNI Internet Protocol-Network to Network Interface ISUP Integrated Services Digital Network User Part ISP Internet Service Provider IXC Inter Exchange Company LATA Local Access and Transport Area LCR Least Cost Routing LD Long Distance LERG Local Exchange Routing Guide LRN Location Routing Number 34 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 LNP Local Number Portability LSMS Local Service Management System MSC Mobile Switching Center NANC North American Numbering Council NANC FON North American Numbering Council Future of Numbering Working Group WG NGGW Non-geographic Gateway NGLRN Non-geographic Location Routing Number NLRN National Location Routing Number NNI Network to Network Interface NNP Nationwide Number Portability NNP WG Nationwide Number Portability Working Group NP Number Portability NPA Numbering Plan Area NPAC Number Portability Administration Center NPDB Number Portability Data Base NPRM Notice of Proposed Rule Making NSP Network Service Provider NXX Exchange RBOC Regional Bell Operating Company PCMU Pulse Code Modulation u-law POI Point of Interconnection p-ANI Pseudo-Automatic Number Identification PSAP Public Safety Answering Type PSTN Public Switched Telephone Network RS Route Server SBC Session Border Controller SIP Session Initiation Protocol SP Service Provider SOA Service Order Administration SS7 Signaling System 7 35 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 TDM Time-Division Multiplexing TN Telephone Number UAC User-Agent Client UAS User Agent Server URI Uniform Resource Identifier URL Uniform Resource Locator VoIP Voice over Internet Protocol Definition of Terms: A All Call Query (ACQ) is the requirement or function of originating Service Providers querying the called party telephone number in the routing database, on every call to determine LRN. Alliance for Telecommunications Industry Solutions (ATIS) is a standards body where companies in the information and communications technology (ICT) industry come together to address common, critical priorities. ATIS is accredited by the American National Standards Institute (ANSI). C Called Party Number (CPN) is a telephone number that has been dialed to reach a destination. Call Session Controller Function (CSCF) represents a series of SIP servers or proxies, collectively called Call Session Control Function (CSCF), are used to process SIP signaling packets in IP call flows. Interrogating - Call Session Controller Function (I-CSCF) is a proxy server retrieves information from IMS core elements for purposes of SIP registration and call set up. Proxy - Call Session Controller Function (P-CSCF) is the first point of contact for the IMS core network. End-user devices connect to the proxy, and it forwards all messaging request to the applicable IMS Core elements registration, security, routing, etc. Serving - Call Session Controller Function (S-CSCF) is the central node of the signaling plane. It is a SIP server but performs session control too. It is always located in the home network. It interfaces to the HSS to download user profiles and upload user to S-CSCF associations. 36 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Class 4 Switch or tandem, telephone switch is a U.S. telephone company central office telephone exchange used to interconnect local exchange carrier offices for long distance communications in the public switched telephone network. It doesn't connect directly to any telephones; instead, it connects to other class-4 switches and to class-5 telephone switches. Class 5 Switch is a telephone switch or telephone exchange in the public switched telephone network located at the local telephone company's central office, directly serving subscribers. Class-5 switch services include basic dial-tone, calling features, and additional digital and data services to subscribers. Competitive Carrier Association (CCA) trade association representing rural wireless communications industry. CTIA  The Wireless Association is a trade association representing wireless communications. D Domain Name System (DNS) a hierarchical and decentralized naming system for computers, services, or other resources connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. E Electronic Numbering (ENUM) is a data type that consists of predefined values, being able to map the same phone number no matter where you are. Exchange (NXX) is the three-digit code that forms the second part of a 10-digit telephone number. The NXX is also known as the  central office code or  exchange . F Federal Communication Commission (FCC) The FCC regulates interstate and international communications by radio, television, wire, satellite and cable in all 50 states, the District of Columbia and U.S. territories. An independent U.S. government agency overseen by Congress, the commission is the United States' primary authority for communications law, regulation and technological innovation. Fully Qualified Domain Name (FQDN) refers to the hostname component of a URI and whose value is determined by a service provider. G Geographic Information System (GIS) An integrated collection of computer software and data used to view and manage information about geographic places, analyze spatial relationships, and model spatial processes. 37 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 H Home Subscriber Server (HSS) is a master user database that supports the IMS network entities that handle calls. It contains the subscription-related information, performs authentication and authorization of the user, and can provide information about the subscriber's location and IP information. I Internet Protocol (IP) is a packet-based protocol used to exchange data over computer networks. IP handles addressing, fragmentation, reassembly, and protocol demultiplexing. It is the foundation on which all other IP protocols (collectively referred to as the IP Protocol suite) are built. Internet Protocol Location Routing Number (IPLRN) is a location routing number that is used to port numbers to and route non-geographically assigned telephone numbers to the IP enabled carriers. IP-Network to Network Interface (IP-NNI) is an interface that specifies signaling and management functions between two networks. An NNI circuit can be used for interconnection of signaling (e.g., SS7), Internet Protocol (IP). It is also the name of a joint ATIS and SIP Forum Task Force. Inter Exchange Carrier (IXC) is a telephone company providing connections between local exchanges in different geographic areas. They also provide local access and transport area services as per the Telecommunication Act of 1996. They are commonly referred to as long-distance carriers. Integrated Services Digital Network User Part (ISUP) is part of Signaling System No. 7 (SS7), which is used to set up telephone calls in the public switched telephone network (PSTN). Link to additional info. Internet Service Provider (ISP) an organization that provides services for accessing, using, or participating in the Internet. L Local Exchange Routing Guide (LERG) The iconectiv® LERG"! Routing Guide is an output from the BIRRDS database. It is used by Service Providers (SP) and other carriers as a common means to reflect and exchange current and planned Central Office (CO) Code (NPA-NXX) and Thousands-Block (NPA-NXX-X) assignments along with associated routing data. Data is provided for all SPs in the North American Numbering Plan (NANP). It is generated monthly in its entirety, with daily change activity also available. See  Telecom Routing Administration (TRA) definition. Least Cost Routing (LCR) the process of selecting the path of outbound communications traffic based on cost. 38 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Local Access Transport Area (LATA) is a geographical area designated as a LATA in the National Exchange Carrier Association. It often defines an area where a Regional Bell Operating Company is permitted to offer exchange telecommunications and exchange access services. Currently, the geographic scope of a local routing number is limited to a LATA, meaning numbers can only be ported within a LATA assignment. Long Distance (LD) is a telephone call made to a location outside a defined local calling area or those calls that cross LATA boundaries. Local Routing Number (LRN) is a ten-digit number in a database called a Service Control Point (SCP) that identifies a switch for a local telephone exchange. The assignment of a location routing number to telephone numbers allows for local number portability. Local Number Portability (LNP) refers to the ability of a "customer of record" of an existing fixed-line, VoIP or mobile telephone number assigned by a carrier to reassign the telephone number to another carrier. Local Service Management System (LSMS) is a system used by a Service Provider which receives data broadcast from the Number Portability Admiration Center (NPAC). The LSMS provisions the Service Provider's downstream systems, such as its call routing database. Legacy Wireline Switch (LWS) is a telephone switch or telephone exchange in the public switched telephone network, directly serving subscribers. Also called a Class 5 Switch or TDM switch, an LWS is a computer specialized for TDM-based, circuit-switched telephone calls. Services include basic dial-tone, calling features, and additional digital and data services to subscribers connected to a local loop. M Mobile Switching Center (MSC) is the primary service delivery node for Global System for Mobile Communications (GSM), responsible for routing voice calls and SMS as well as other services. It also enables mobile devices to communicate with other mobile devices and telephones in the Public Switched Telephone Network (PSTN). N North American Numbering Council (NANC) is a Federal Advisory Committee that was created to advise the Commission on numbering issues and to make recommendations that foster efficient and impartial number administration. NANC Future of Numbering Working Group (NANC FON WG) a working group that was once formed by the NANC to discuss a wide array of Numbering issues and is no longer operational. Non-geographic Gateway (NGGW) are VoIP nodes, that host NGLRNs and provide connectivity to Service Providers that port in NNP TNs. 39 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Non-geographic Location Routing Number (NGLRN) is a model supporting nationwide number portability by establishing a new numbering admiration network gateway function for the assignment and porting of telephone numbers to NGLRN vs. a traditional local routing number. National Location Routing Number (NLRN) is model supporting nationwide number portability using existing LRNs. The approach allows TNs to be ported beyond the current LATA boundaries, thereby allowing TNs to be made available to customers in any geographic location across the nation. Nationwide Number Portability (NNP) is the ability of users of telecommunications services to retain existing telecommunications numbers without impairment of quality, reliability; or convenience when switching from one telecommunications carrier to another or when moving from one physical location to another. Nationwide Number Portability Working Group (NNP WG) is a working group formed by the NANC to discuss the process of moving from geographic number portability to national number portability. Network to Network Interface (NNI) an interface that specifies signaling and management functions between two networks. Network Service Provider (NSP) a business or organization that sells bandwidth or network access by providing direct Internet backbone access to internet service providers and usually access to its network access points. Notice of Proposed Rule Making (NPRM) a public notice that is issued by law when an independent agency of the US government wishes to add, remove, or change a rule or regulation as part of the rulemaking process. Number Portability (NP) allows the customer of record to reassign the number to another carrier ("Service Provider portability"), move it to another location ("geographic portability"), or change the type of service ("service portability"). Number Portability Data Base (NPDB) see Number Portability Administration Center (NPAC). Numbering Plan Area (NPA) divides territories into Numbering Plan Areas (NPAs), each identified by a three-digit code commonly called area code. The NPA is the first three digits of a ten-digit telephone number (NPA)-NXX-XXXX or 303-372-1000. Number Portability Administration Center (NPAC) The database that contains routing information on ported Telephone Numbers (TN) and Thousands-Block Number Pooled Thousands-Blocks (NPA-NXX-X) and facilitates the updating of the routing databases of all subtending Service Providers (SP) in the portability area. Also called the Number Portability Administration Center (NPAC) Service Management System (SMS) 40 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 P Pseudo-Automatic Number Identification (p-ANI) A 10-digit number used for the purpose of routing an E9-1-1 call to the appropriate Public Service Answering Point (PSAP). P-ANIs include but are not limited to: ESRD, ESRK, and ESQK numbers. If a North American Numbering Plan (NANP) Telephone Number (TN) is used as a p-ANI, this number cannot be Assigned to a customer. See  Administrative Numbers definition. Public Switch Telephone Network (PSTN) is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local telephony operators, providing infrastructure and services for public telecommunication. The PSTN consists of telephone lines, fiber optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables, all interconnected by switching centers. Thus, allowing most telephones to communicate with each other. Originally a network of fixed-line analog telephone systems, the PSTN is now almost entirely digital in its core network and includes mobile and other networks, as well as fixed telephones. Post Code Modulation u-law (PCMU) a method used to digitally represent sampled analog signals. Point of Interconnection (POI) The physical location where a Service Provider's (SP) connecting circuits interconnect for the purpose of interchanging traffic on the Public Switched Telephone Network (PSTN). Public Safety Answering Point (PSAP) a call center where emergency calls initiated by any mobile or landline subscriber are terminated. R Route Server (RS) is a routing server for a SIP network. Route Server can be deployed as a routing server for Local Number Portability queries. S Session Border Controller (SBC) is a network element deployed to protect SIP based Voice over Internet Protocol (VoIP) networks. The functions include security, connectivity between networks, quality of services policy, and media (voice, video, and other) services. Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, modifying, and terminating real-time sessions that involve video, voice, messaging and other communications applications and services between two or more endpoints on IP networks. Service Provider (SP) is a company that has traditionally provided telephone and similar services allowing users to send and receive telephone calls and faxes. 41 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Service Order Administration (SOA) is a hosted or managed service that automates the process of updating the Number Portability Administration Center (NPAC) during the number porting process. Signaling System 7 (SS7) is an architecture for performing out-of-band signaling in support of the call-establishment, billing, routing, and information exchange functions of the public switched telephone network (PSTN). Link to Wikipedia. Subscription Version A reference to the subscriber s TN information and the current service provider porting info to facilitate data downloads to the Network. T Time-Division Multiplexing (TDM) is a method of putting multiple data streams in a single signal by separating the signal into many segments, each having a very short duration. Each individual data stream is reassembled at the receiving end based on the timing. Telephone Number (TN) is a sequence of digits assigned to a fixed-line telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone, or to other devices for data transmission via the public switched telephone network (PSTN) or other public and private networks. U User Agent (UA) collectively the User Agent Client (UAC) and User Agent Server (UAS) is used to establish connections and enable sessions between users and the IMS network. Uniform Resource Identifier (URI) is a string of characters that unambiguously identifies a logical or physical resource on a network, of which the best-known type is the web address or URL. Uniform Resource Locator (URL) colloquially termed a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. V Voice over Internet Protocol (VoIP), also called IP telephony, is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks. 42 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Appendix D: Minority Report North American Numbering Council National Number Portability Technical Working Group Minority Report Richard Shockey SIP Forum Member FCC North American Numbering Council I wish to congratulate the members of the technical sub-working group for their efforts under extremely difficult circumstances. The challenges they face were not of their own making but reflected difficult time lines and challenging policy and economic choices that were beyond the scope of the referral made to the NANC by the Wireline Competition Bureau. Regretfully I cannot support the report for the principal reason that includes references to IP- LRN (formally NG-LRN) which, in my opinion, should not have been included for consideration as a possible technical solution to the National Number Portability issue. In my judgement the working group should have focused its limited resources on the N-LRN solution as the only viable option. In the previous report to the NANC we rejected out of hand the GR-2982 Core (GUBB) solution as in appropriate since it relied on modification to SS7 to implement. It has been apparent for years that SS7 or the entire TDM network architecture cannot and should not be modified as we continue down the road of the all IP Transition of the Voice Communications network of the United States. The principal issue in IP-LRN s is to facilitate interconnected SIP/IMS networks and tangentially proports to solve the problem of National Number Portability. IP-LRN s are attempting to solve a business model problem for IP centric service providers that should properly be addressed in the Technology Transitions proceeding which has been ongoing for many years now. The issue of how to facilitate all IP Interconnection for Real Time Voice Communications using NANP numbering has been understood for nearly 20 years and has been well documented. I have been directly involved in many of those efforts. 43 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 I would point out several relevant items. First. For nearly 9 years I was the co-chair of the IETF ENUM working group that produced RFC 6116. ENUM relies on the use of Domain Name System (DNS) technology to perform a number to URI translations. This technology is in use today and is the basis of the ITRS database maintained by the FCC to facilitate the Telephone Relay Service and may be used to help facilitate Video Relay services in the future. ENUM works, its fast, highly saleable though it does have some shortcomings that I will not elaborate on here. Second. The NANC many years approved a variety of URI fields in the NPAC that could be used for phone number to URI translations at a service layer granularity. Voice Video Text etc. These are collectively the NANC 400 fields. I was directly involved in the design of those fields. Since the introduction of those fields. NOT ONE SERVICE PROVIDER IN THE US HAS EVER PROVISIONED A SINGLE NANC 400 NPAC FIELD. Third. ATIS and the SIP Forum Network to Network TF tried to deliver to the industry a consensus report on IP interconnection and we concluded there was NO CONSENSUS. ENUM was studied as an option. For now, the elements of the industry are satisfied with negotiated bi- lateral agreements. This may have to change in the future but IP-LRN s are not the optimal technical solution. https://www.sipforum.org/download/joint-atissip-forum-technical-report-ip-interconnection- routing-atis-1000062-sipforum_twg-6/?wpdmdl=2780 Fourth. It should be pointed out that the Commission has steadfastly refused to classify Interconnected VoIP as a Title II service. The Commission has used its plenary numbering authority under Section 252(e) 1 of the Act to impose mandatory 911 and LNP obligations on VoIP service providers. In my judgement the Commission would have to revisit that decision if it choose to take the IP-LRN solution seriously. Fifth. The IP-LRN proposal has been significantly modified from its original NG-LRN form that would have potentially mandated IP Gateways in every rate center and LATA s. The Commission has been trying to nudge the industry away from rate centers and LATA s but as the Intercarrier Compensation reform effort proved there is still significant resistance to that effort. 44 NANC NNP WG Report Report on Nationwide Number Portability July 28, 2020 Other Consideration The Technical subcommittee correctly concluded that there are several issues beyond the scope of the technical working group that will have to be considered if there is to be progress on implementing National Number Portability. First. It is not clear to me Commission is prepared to address the forest of issues surrounding ratings and tariffs especially on the problem of Originating Access charges. I have serious doubts NNP can proceed without forcefully addressing this challenge. Second. It is not clear whether IP-NNP or a national system of IP Interconnection will require service providers, especially smaller rural carriers would be forced into accepting the burden of Bi-Directional transport costs to new all IP points of interconnection. Third. It is not entirely clear whether NNP requires the imposition of National 10 Digit Dialing which would have not just economic impacts but political impacts on states that still permit 7- digit local dialing such as Montana, North Dakota South Dakota, Maine, Vermont, Delaware, Alaska etc. Fourth . The economic impact of All Call Query on smaller service providers is not well understood. Especially the significant costs of equipment upgrade to enable a localized full cache of the NPAC which NNP would probably require. This is an industry with very very thin margins and some networks are more advanced than others. This begs the question raised in the NNP WG of whether it is technically feasible to permit some elements of the industry to enable NNP and establish a timeline for others to follow. Some observers have noted that the impending STIR/SHAKEN Call Authentication Mandate outlined by Chairman Pai and now pending before Congress may result in a mandate to all IP interconnection since the Call Authentication data can only survive carrier to carrier if the call signaling remains SIP/IMS in the call path. There is merit to this argument. Only time will tell if this is the case. It should be noted that STIR/SHAKEN imposes real and significant costs to the industry. In any event the combination of STIR/SHAKEN and NNP and all IP Interconnection may be a  Bridge to Far for the industry. 45