1、 ATIS-0300065 LOCATION ROUTING NUMBER (LRN) ASSIGNMENT PRACTICES Reissued with the resolution of Issue 757 September 5, 2014 Copyright 2014 by the Alliance for Telecommunications Industry Solutions, Inc. All rights reserved. The Location Routing Number (LRN) Assignment Practices dated September 5, 2
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14、 THE RISK OF THE USER. NOTE - The users attention is called to the possibility that compliance with this standard may require use of an invention covered by patent rights. By publication of this standard, no position is taken with respect to whether use of an invention covered by patent rights will
15、be required, and if any such use is required no position is taken regarding the validity of this claim or any patent rights in connection therewith. LRN Assignment Practices September 5, 2014 ATIS-0300065 1Location Routing Number Assignment Practices These practices are intended to assist Service Pr
16、oviders as to why Location Routing Numbers (LRNs) are necessary and how to select their own LRNs. The use of LRNs is covered in the ATIS Packet Technology Systems Committee (formerly Committee T1S1) standards and the FCC North American Numbering Council Local Number Portability Administration Workin
17、g Group (LNPA WG) best practices1and some of that direction is incorporated in these practices. An LRN is a 10-digit number, in the format NPA-NXX-XXXX, that uniquely identifies a switch or point of interconnection (POI) per LATA. The NPA-NXX portion of the LRN is used to route calls to numbers that
18、 have been ported. The following LRN assignment criteria should be considered when a service provider selects and assigns an LRN: 1. A unique LRN will be provisioned to identify each recipient switch or POI in the number portability capable network2. LRNs are to be used for routing and not for ratin
19、g/billing calls. Calls are rated and billed to an end-user based on the dialed digits and not on the LRN. There is, however an Automated Message Accounting feature that records the LRN that a call is routed to in order to determine the appropriate provider serving that number for access billing purp
20、oses3. 2. A service provider will establish one (1) LRN per LATA from an assigned NXX for each recipient switch or POI in the number portability capable network. Additional LRNs may be used for internal purposes. Further, additional LRNs are not required to identify US wireline rate centers. A uniqu
21、e LRN may be assigned to every LNP equipped switch or POI (and potentially to each CLLI4listed in the iconectiv LERG Routing Guide). Requesting an additional NXX to establish an LRN in certain instances may be justified but precautions need to be taken to ensure number resource optimization. The fol
22、lowing points should be considered prior to requesting a new NPA-NXX for the purpose of establishing an LRN: The requesting service provider uses an existing code already homed to the tandem where the LRN is needed for the POI. Once the NXX Code is assigned, the Code Holder must return any blocks no
23、t justified for retention in its inventory. When there are multiple tandems owned by different SPs in a single LATA, the requesting SP may obtain a new NXX in order to establish an LRN for each subtending POI. Regulatory waivers granted to ILECs to carry local calls across a LATA boundary may exist.
24、 In such instances, SPs may be justified in establishing an additional LRN to properly route calls. 3. Remote switches that have a unique, assigned NPA-NXX also may have a unique LRN assigned to the remote switches5. 1See the LNPA WG pages at . 2ATIS PTSC Standard: Number Portability for Switching S
25、ystems ATIS-1000002, October, 2004 (documents available at the ATIS Document Center at www.atis.org may have an associated fee). 3See footnote 2. 4CLLI and LERG are trademarks of Telcordia Technologies, Inc. dba iconectiv. 5See footnote 2. LRN Assignment Practices September 5, 2014 ATIS-0300065 24.
26、The LRN must be selected and assigned from a valid NPA/NXX that has been uniquely assigned to the service provider by the Central Office Code Administrator and published in the LERG Routing Guide. An LRN should be selected and assigned with the following considerations: Do not select and assign the
27、LRN from an NPA/NXX that is planned to be re-homed to another switch. Do not select and assign the LRN from an NPA/NXX that has a majority of the NXX numbers assigned to a single customer. Do not assign the LRN from an NPA/NXX that is assigned to the local choke network. Do not assign the same telep
28、hone number as both an LRN for a switch and a working number for a customer. Do not assign any TLDN or ESRD/ESRK wireless administrative number as an LRN. Do not select and assign the LRN from a block that otherwise may be eligible for donation to the thousands-block number pool.6 5. An LRN may have
29、 to be changed due to any of the following: switch replacements code moves or LERG reassignments NPA Splits (as a result of an NPA-NXX split, a service provider may have to change their assigned LRN) Donation or return of the thousands-block containing the LRN 6. If a switch serves multiple NPA/NXXs
30、, wherever possible, do not select and assign the LRN from an NPA that has been identified for area code relief. 7. The LRN will be published in the LERG Routing Guide7. LERG Routing Guide LRN records are used by some SPs for trouble shooting and network engineering purposes. Within five business da
31、ys of theassignment of an NXX that is to be used for LRN purposes, or when an LRN is assigned from an NXX already in an SPs inventory, the SP should forward a CO Code Part 2 Form 7 to its AOCN for input into Business Integrated Routing and Rating Database System (BIRRDS). 8. Service providers must m
32、aintain internal records of LRNs as a separate sub-category of “Administrative” in their TN inventories. (FCC 00-104 36 and 62), (see also 47 CFR 52.15 (f) (1) (i) 9. Shared service provider NPA-NXXs should not be used for LRN assignments. 10. For thousands-block number pooling, the LRN shall only b
33、e selected and used by the Code Holder from its assigned/retained thousand block(s). 6An SP can avoid the donation of blocks containing administrative numbers, e.g., LRNs, Temporary Local Directory Numbers (TLDNs), Mobile Station Roaming Numbers (MSRN), by consolidating these numbers within blocks i
34、t intends to retain. The porting of an LRN can cause call delivery failures. 7At a minimum LRNs that are associated with ported and/or pooled records in the NPAC should be published in the LERG Routing Guide. Failure to publish LRNs in the LERG Routing Guide leads to confusion and more investigation time during the resolution process to determine to whom the LRN belongs.
