1、 TECHNICAL R EPORT ATIS-1000071 Technical Report on a Nationwide Number Portability Study As a leading technology and solutions development organization, the Alliance for Telecommunications Industry Solutions (ATIS) brings together the top global ICT companies to advance the industrys most pressing
2、business priorities. ATIS nearly 200 member companies are currently working to address the All-IP transition, netw ork functions virtualization, big data analytics, cloud services, device solutions, emergency services, M2M, cyber security, network evolution, quality of service, billing support, oper
3、ations, and much more. These priorities follow a fast-track development lifecycle from design and innovation through standards, specifications, requirements, business use cases, softw are toolkits, open source solutions, and interoperability testing. ATIS is accredited by the American National Stand
4、ards Institute (ANSI). The organization is the North American Organizational Partner for the 3rd Generation Partnership Project (3GPP), a founding Partner of the oneM2M global initiative, a member of and major U.S. contributor to the International Telecommunication Union (ITU), as w ell as a member
5、of the Inter-American Telecommunication Commission (CITEL). For more information, visit w ww.atis.org. Notice of Disclaimer NP Query at IXC Switch . 10 Figure 5.1 Call Flow to a Ported Number 12 ATIS TECHNICAL REPORT ATIS-1000071 ATIS Technical Report on Nationwide Number Portability Study 1 1 Scope
6、, Purpose, NP Query at IXC Switch IXC-Routed Call; NP Query at IXC Switch For this case, the Originating Switch determines that the call is to be routed to an IXC, and does not perform the NP query. The NP query is performed at the IXC Switch, and the call is routed onward to the Recipient Switch. I
7、n this example, the IXC has direct trunks to both the Originating and Recipient Switches. The following steps are illustrated in Figure 4.4: ATIS-1000071 11 1. Subscriber A (305-224-1111) dials Subscriber B (1-708-713-2222). 2. The Originating Switch performs digit analysis on the dialed digits to d
8、etermine how to route the call. The switch determines that routing to the called DN (Subscriber B) requires routing to an IXC and does not perform the NP query. 3. The Originating Switch signals, using SS7 signaling, the dialed number to the IXC Switch using existing procedures. 4. The IXC Switch pe
9、rforms digit analysis on the incoming digits to determine how to route the call. The switch determines that the called DN (Subscriber B) is in a portable NPA-NXX (708-713) and verifies that conditions have been met such that a query should be sent. 5. The IXC Switch sends a query based on the dialed
10、 digits to the NPDB. 6. The NPDB sends a response containing the LRN (708-979-xxxx) of the Recipient Switch. 7. The IXC Switch receives the NPDB response and analyzes the data. The LRN is translated in the NP Routing Tables and an ISUP route out of the switch is determined. 8. The IXC Switch signals
11、, using SS7 signaling, the LRN in the IAM CdPN to the Recipient Switch. The IAM includes a “Ported Number” GAP containing the dialed digits and the FCI Ported Number Translation indicator is set to “translated number.” 9. The Recipient Switch performs digit analysis on the incoming digits to determi
12、ne how to route the call and determines that the DN is on the switch. 10. The Recipient Switch completes the call to the terminating subscriber. A number of services in use today rely upon SS7 signaling. These include Line Information Database (LIDB) (alternate billing services), CLASS, Calling Name
13、 (CNAM), and Inter-Switch Voice Messaging (ISVM). Prior to NP, the SS7 network used six-digit GTT procedures (analysis of NPA-NXX) to route messages for these services to the target system. Once a given NPA-NXX is supported in multiple target systems, a GTT function based on ten-digit analysis is ne
14、eded to correctly identify the target system. For those services that do not need to operate between networks, six-digit GTT procedures may continue to be adequate. The support of these services between networks is dependent upon bilateral business agreements. Ten-digit GTT may be needed within a ne
15、twork if intra-service provider porting takes place. NP is transparent to the end user. NP is a network capability which allows the DN of an end user to be moved from one switch to another within the rate center. There may be some feature limitations when the end user changes their service to a diff
16、erent service provider. Some features previously used by the customer may not be supported by the new service providers network. Also, some features may no longer work because they require an intra-switch or intra-network relationship with other users that no longer exists once the customer changes
17、to the new service provider. 4.3.1 IP Networks IP networks currently support number portability through a variety of arrangements. These may include performing LNP queries of a Transaction Capabilities Application Part (TCAP) NPDB through interworking from Internet Protocol (IP) protocols as discuss
18、ed in ATIS-1000047 and ATIS-1000051 or mapping NP information from the LSMS into a Domain Name Server (DNS) namespace to support an E.164 Number Mapping (ENUM) query as in RFC 4679. In call set up NP information elements are mapped into Session Initiation Protocol (SIP) messages as described in ATIS
19、-1000679 and RFC 4694. 5 Commercial Agreement NNP Solution Wireless carriers with a nationwide footprint may allow customers to move outside the LATA associated with their number by treating them as permanent roamers. Likewise, they can port in the numbers of customers that have moved outside their
20、original LATA by porting the numbers to their Point of Interconnection (POI) in the original LATA. Since the POI in either case remains in the original LATA end user billing, interconnection and settlements are not changed. ATIS-1000071 12 It has been suggested16that an interim solution to nationwid
21、e portability could be achieved by using the facilities of third parties 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. The call flow to a ported number is shown in the figure below: Figure 5.1 Call Flow to a Ported
22、 Number Note that issues relating to the LRN used to port the number to the third party POI may need to be examined by the ATIS Industry Numbering Committee (INC) and LNPA Working Group, and the Numbering Oversight Working Group (NOWG): In order for the recipient carrier to appear as a wireless carr
23、ier in industry databases, must the LRN be assigned to the recipient carrier rather than the third party provider? If so, will this require assignment of an LRN to each wireless carrier in each LATA from which they wish to port in numbers, and what impacts would be expected to the North American Num
24、bering Plan (NANP)? 6 National LRN Implementation of NNP The approach described in this clause allows LRNs to be used outside of the current LATA boundaries thereby allowing TNs to be “ported” nationally. This solution assumes that service providers will be permitted to have LRNs in multiple regiona
25、l NPACs to identify current customers service market. To affect this approach, processes are involved in the call set up, including signaling, and responsibilities exist as to which service provider will perform dips to obtain the LRN to address how the dialed Telephone Number (TN) is then processed
26、 to properly terminate the call. Such processes and responsibilities are additional areas of consideration that need to be assessed relative to NNP impacts. However, this solution takes a straightforward approach leveraging 16Level 3 presentation at CCA/CTIA meeting of August 31, 2015. ATIS-1000071
27、13 todays infrastructure since it utilizes existing call routing functionality, without the “costs” of additional administrative overhead. This approach for NNP using national LRNs acknowledges that there are both routing and non-routing impacts as well. This clause identifies but does not address s
28、pecific mitigation approaches to non-routing impacts. It may be noted that the industry has some experience with the effects of removing the edit preventing inter-LATA porting as a result of measures taken in response to hurricane Katrina and subsequent storms.176.1 Routing Impacts This proposal min
29、imizes the changes required to the processes surrounding the routing of ported TNs by utilizing the existing routing infrastructure. Another benefit of this approach is that it allows carriers with a nationwide footprint to associate customers who have physically moved outside the rate center or LAT
30、A associated with their NPA-NXX to an LRN in the rate center or LATA in which they now reside. This proposal allows “permanent roamer” calls to be routed appropriately based on the nationwide use of LRNs while assisting the service providers in determining the correct interstate/jurisdictional natur
31、e of the call based on the location of the LRN assigned. Although there are some aspects of LRN routing that need to be considered when taking LRN routing outside the current constraints placed on LRNs by rate centers and LATAs, existing LRN routing principles can effectively support the routing asp
32、ects of NNP. Some aspects that have to be addressed include but are not limited to: Current NPAC system processes require the LRN and TN NPA-NXX components to be associated to the same LATA. Some assessment of network equipment (e.g., switches) ability to handle substantially more NPAs (due to poten
33、tial ported TNs from a much wider base of NPAs than the equipment may handle today) needs to be performed. The impact to the N-1 lookup requirement. Service providers would need to conduct an assessment to determine the network impacts of either performing all queries at the point of origination, or
34、 maintaining the N-1 call completion scenario with the understanding that those TNs porting outside the LATA require additional routing. 6.2 Non-Routing Impacts From a routing perspective, the existing LNP/LRN process can support NNP and by doing so, network impacts and efforts can be minimized. One
35、 of the major benefits of this approach is that it requires minimal changes to the administration or assignment of numbering resources. Some non-routing issues exist relative to this proposal. These include, but are not limited to: NNP will impact many industry processes including call detail record
36、 processing, subscriber billing, caller ID issues (e.g., systems that default Caller Name as viewed by the called party to a rate center or state exacerbating a consumer issue that exists with wireless calls today). Tariffs, toll-free (Short Message Service SMS) processing, Enhanced 9-1-1 (E9-1-1),
37、as well as many other processes have some aspects that may key on the relationship of a TN to a rate center and/or a LATA. The porting-in service provider may not have a presence in the ported-out area. In general, appropriate business agreements may need to exist between the port-in and port-out se
38、rvice providers. These situations are addressed within the current LNP LATA environment; however, NNP extends these situations nationally. 17These impacts are discussed in an LNPA Working Group report, available at: . ATIS-1000071 14 Dialing plan consistency (e.g., national 1+ dialing) may be needed
39、. For example, variations exist across the country with respect to the way calls can/should be dialed, i.e., 1+10 digits, 10 digits, and/or 7 digits. Dialing plans are often related to the routing rules associated with the dialed number. For example, local calls originating and terminating within th
40、e same NPA, especially if only one NPA today serves the area, are usually dialed on a seven digit basis. NNP impacts on the varying dialing plans needs to be assessed. Numbering resources are state-managed. Porting TNs out-of-state raises questions of regulatory and service provider responsibilities
41、, liabilities, and numbering resource management. State regulatory oversight aligns with NPA boundaries (all NPAs have geographical boundaries that lie within a given state) and all rate center boundaries lie within a given state. Rare isolated cases may exist between states having a common border t
42、o address various dialing and servicing issues for small areas. NNP would, in many cases, be moving a TNs relationship to geography outside the state of the base NPA, resulting in potential issues with existing state regulations, policies, etc. Consumer issues include but are not limited to: o Consu
43、mers with geographic-based rate plans keyed on rate center or LATA considerations need to be clearly aware of how a call they place aligns with their rate plan. o Call completion issues may arise when routing to TNs that have moved from a specific rate center/LATA geography to anywhere within the na
44、tional footprint. o Toll/call blocking software that blocks calls based on the local/toll relationship the calling number has to the called number based on NPA-NXX, would need to determine local/toll at a TN level or rely on some indication that a call is toll/not toll, etc. o Caller ID/Name impacts
45、 need to be assessed. o Consumer billing confusion. This is especially true if local/toll plans are involved, and having calls to the same NPA-NXX that are sometimes local and sometimes toll. Other issues: o SMS 800 The impacts on SMS 800 need to be assessed since there could be restrictions on toll
46、-free calling based on calling party location (e.g., a toll-free service could be set up to work on an intraLATA basis only) which could impact consumers e.g., if a customer ports a New York City TN to Los Angeles, and a toll-free number is set to only work in LATA 132 (New York City area), it is no
47、t clear whether a call from the New York City TN (which is now assigned to Los Angeles LATA 730) to the toll-free number will be allowed. o Local Systems The impacts to local systems, both Service Order Administration (SOA) and LSMS would need to be assessed. Dependencies, assumptions, or design and
48、 implementation decisions likely exist regarding the relationships between NPAs, NXXs, LRNs, and geographic areas of service and/or single NPAC regions. Present system implementations may be based on the current porting rules regarding porting only within a single LATA and/or NPAC region, and the fa
49、ct that an LRN only can be associated with a single NPAC region, as well as that a ported TN record can only exist in one NPAC region. o Service Providers Number Management Systems A need to assess whether “edits” would need to be updated to allow for TNs to be assigned to switches that are outside of the area. 6.3 Transition to IP This solution can evolve into an all-IP environment. Although there is no industry consensus on how to route calls in an IP enviroment, many of the IP routing scenarios proposed do not change any of
