Enterprise Use Cases and ALevel Attestation Additional Use

Enterprise Use Cases and A-Level Attestation Additional Use Cases and Central TN Database approach Peter Brown | August 2019 Based on IPNNI-2019 -00071 R 002

Restating the problem } Service providers must be able to sign with A-level attestation calls from an enterprise which is using calling numbers from a different service provider. } To deliver this, we explore an approach involving an authoritative source of: › TN-to-Enterprise association › Delegated authority by TN Providers. Metaswitch Networks | Proprietary and confidential | © 2019 | 2

Requirements statements } These requirements have come from the user community as well as industry partners – enterprise customers, carriers, etc: › Carriers need a consistent set of rules that they will apply for signing for enterprises. › Carriers need assurances about an enterprise’s delegated authority to use TNs. › The access and retrieval of Enterprises’ assigned TN information must be secured. › The Originating Service Provider has to be responsible for signing the call (for traceability and accountability). • Hence Enterprise self-signing is excluded from this approach. › › › Avoid multiple Identity Headers in signed calls. Minimise the impact on Enterprises. Simplify the complexity for Carriers. Enterprises should have the ability to use toll-free numbers as their calling numbers. Enterprises should have the ability to port their numbers from one carrier to another. Metaswitch Networks | Proprietary and confidential | © 2019 | 3

Updated Use Cases Metaswitch Networks | Proprietary and confidential | © 2019 | 4

Use Case 1: Single TNSP, Single OSP } Minor update: } The PASSpor. T is signed using an STI-Certificate with a TNAuthlist containing a single SPC with a value assigned to OSP AB Metaswitch Networks | Proprietary and confidential | © 2019 | 5

Use Case 8: Call Center – a dynamic variant of Use Case 2 } Enterprise may be using a Business Process Outsourcing Contact Center for outbound call campaigns › Contact Center has no TNs natively assigned › Contact Center receives a list of TNs when the campaign is defined. } Number blocks may be fast-changing } OSP choice may be fast-changing (due to LCR, say) Metaswitch Networks | Proprietary and confidential | © 2019 | 6

Use Case 9: LNP update } Not a call scenario } Any solution approach must ensure that A-level attestion can be maintained for an Enterprise when it has ported a number from one TNSP to another Metaswitch Networks | Proprietary and confidential | © 2019 | 7

Central TN Database Approach Metaswitch Networks | Proprietary and confidential | © 2019 | 8

Central TN Database activity on TN assignment 1. Enterprise requests TNs CTND 2. Carrier informs CTND › Issues to be addressed: • Enterprise ID must be unique – assigned and managed by the CTND • Posted TNs should be unique (except 8 xx) therefore CTND responses must include error cases. POST /TN_ENTERPRISE_LIST • • • TN range Enterprise ID Expiry date Carrier A SPID Carrier A cert URL Carrier A signature 3. Carrier provides TNs to Enterprise 2 Carrier A OSP TNSP 1 Enterprise Metaswitch Networks | Proprietary and confidential | © 2019 | 9 3

Central TN Database activity on receipt of SIP INVITE a) Enterprise sends INVITE CTND b) Carrier requests from CTND › GET /TN_STATUS • • (mutual TLS) Query TN & Enterprise ID b c) CTND responds with › › Expiry date Owning TNSP SPID CTND cert URL CTND signature d) Carrier can verify that a valid TNSP has provided TN to Enterprise. Carrier sends INVITE with attestation level A PASSpor. T Metaswitch Networks | Proprietary and confidential | © 2019 | 10 Note: (b) and (c) could operate on cached/subscribed information c Carrier A d OSP TNSP a Enterprise

Use Cases Revisited with CTND Metaswitch Networks | Proprietary and confidential | © 2019 | 11

Use Case 2: TNSP A, OSP B } Carrier ‘A’ is one of many possible Originating SPs, and also one of many TN Providers } Enterprise has purchased TNs from multiple TNSP, including Carrier ‘A’ } Enterprise has trunks to multiple carriers, including Carrier ‘B’, for outbound call origination } For each number range provided to the Enterprise, a TN Provider will have submitted an entry to the Central TN Database › Optionally, these will have been signalled to the Central TN Database Client Service at each carrier that is registered with the Database } When the Enterprise sends an INVITE to an Originating SP › The OSP queries their Central TN Database Client Service to confirm that the number has been registered as “in use” by that Enterprise by a valid TN Provider Metaswitch Networks | Proprietary and confidential | © 2019 | 12

Use Case 2: TNSP A, OSP B 1. Initial TN assignment to Enterprise from Carrier A acting as TNSP CTND TNSP A informs CTND about Enterprise TN assignment. 2. Enterprise is able to initiate A-level attested calls through OSP B uses CTND information to ensure that Enterprise has permission to use TN. 1 Carrier B OSP Carrier A TNSP 1 2 Metaswitch Networks | Proprietary and confidential | © 2019 | 13 Enterprise

Use Case 4: 8 xx calls } Enterprise originates calls using 8 xx numbers } Enterprise may split their outbound traffic between multiple carriers, including Carrier ‘A’, and switch often to minimize cost and improve reliability } 8 xx numbers used by the Enterprise may be resporg’d by one owner, but carried across multiple Service Providers } Implications for Central TN Database › More than one Enterprise can use one 8 xx number › There can be multiple Enterprise IDs associated with each 8 xx number in the database Metaswitch Networks | Proprietary and confidential | © 2019 | 14

Use Case 8: Call Center } Enterprise may be using a Business Process Outsourcing Contact Center for outbound call campaigns › › Contact Center has no TNs natively assigned Contact Center receives a list of TNs when the campaign is defined. } Number blocks may be fast-changing } OSP choice may be fast-changing (due to LCR, say) } Enterprise must inform their TNSP that TNs have been assigned (and when unassigned) to Contact Center } TNSP must pass this information to CTND Metaswitch Networks | Proprietary and confidential | © 2019 | 15

Use Case 8: Call Center CTND 1. Initial TN assignment to Enterprise from Carrier B acting as TNSP 2. Enterprise provides a subset of TNs to Call Center 3. Enterprise informs TNSP 4 1 Carrier A OSP Carrier B TNSP 4. TNSP informs CTND 1 5. Call Center is able to initiate Alevel attested calls through its preferred OSP(s). 5 3 Enterprise 2 Call Center Metaswitch Networks | Proprietary and confidential | © 2019 | 16

Use Case 9: Central TN Database updates due to LNP } TNSPs must inform the CTND about LNP updates within number ranges that have been assigned to enterprises } The source carrier (from which a TN has been ported) must specify the remaining range of numbers that has been assigned to an enterprise which is still owned by that carrier } The destination carrier (to which a TN has been ported) must specify that this TN is assigned to the enterprise and is now owned by this carrier PUT /TN_ENTERPRISE_UPDATE TN/TN-list ported-out Enterprise ID Expiry date Carrier A SPID Carrier A cert URL Carrier A signature CTND POST /TN_ENTERPRISE_LIST TN/TN-list ported-in Enterprise ID Expiry date Carrier B SPID Carrier B cert URL Carrier B signature Carrier B Carrier A OSP TNSP Metaswitch Networks | Proprietary and confidential | © 2019 | 17 OSP TNSP

Proposed next steps } Reach agreement on incorporating content into IPNNI-00071 R 002 › Use Cases › Central TN Database approach } Associated issues to be resolved › Enterprise ID administration › Error cases to be returned from CTND API requests • In particular, whether DNs will be enforced as unique in the CTND Metaswitch Networks | Proprietary and confidential | © 2019 | 18