# Inventorying a legacy PBX before migration Canonical: https://warmtransfer.net/knowledge/pbx-discovery-inventory Last verified: 2026-10-14 Cisco's guidance for a Unified CM to Webex Calling migration calls assessing the current on-premises environment and deployment a key planning activity, covering licensing, locations, devices, users, PSTN, features, integrations and network readiness[^39]. Webex Calling Migration Insights takes Unified CM data as a.tar file generated with the Unified CM Bulk Administration Tool and reports on device eligibility, feature usage, DID usage and devices and users that should migrate together[^19][^15][^17][^16][^20]. ## Exporting configuration from Unified CM In Unified CM, the BAT export at Bulk Administration > Import/Export > Export produces a.tar archive[^3]. The archive contains 1 CSV per exported item plus a header file that lists the source server, the export time and the contents[^3]. You download the archive from Bulk Administration > Upload/Download Files[^3]. The Check Dependency option in the export selects dependent items only 1 level deep[^1]. Do not modify the User ID, User Pkid, Password and Pin fields in enduser.csv, because the credential fields are stored encrypted[^2]. To open Migration Insights in Control Hub, go to Services > Updates & Migrations and use the Migration Insights card in the Unified CM upgrade utilities section[^14]. The upload limit for the Unified CM.tar file is 350 MB[^23]. Cisco states that Migration Insights deletes the uploaded tar file and related data after it generates the reports, and that it keeps no user data beyond report generation[^22]. For FedRAMP (Webex for Government) organizations, the commercial device eligibility check in Migration Insights sends device MAC addresses to Cisco's corporate network[^18]. Organizations that do not want this can use the separate FedRAMP device migration process[^18]. See also [Cisco unified communications manager](https://warmtransfer.net/knowledge/cisco-unified-communications-manager). ## Separating configured features from used ones Cisco advises first identifying which Unified CM features are configured and then assessing which are actually used, using Migration Insights, CDR data and Cloud-Connected UC analytics[^40]. WarmTransfer's reading of the sources is that a configuration export alone, such as a Unified CM BAT.tar, shows what is configured but not what is used, so a usage source such as CDRs is needed to find routing and features that are live but undocumented[^7]. Migration Insights accepts CDR files up to 2 GB[^13]. The files must first be run through Cisco's CDR Preprocessing script and then uploaded as.gzip[^13]. Migration Insights produces these usage reports[^17][^16][^24]: - **FeatureUsageWithLastUsageDateReport.csv** gives usage counts and last-use dates for hunt pilots and call queues, taken from the uploaded CDRs[^17]. - **DidUsageReport.csv** reports the usage of both assigned and unassigned DIDs[^16]. - **The usage-based eligibility report** marks a device Unknown when its CDRs show features that Webex Calling does not support, and the article says to contact Cisco TAC in that case[^24]. See also [SMDR call records from legacy PBXs](https://warmtransfer.net/knowledge/smdr-legacy-call-records). ## Sites, users and groupings Cisco's Prepare guidance has the per-site inventory record the following[^43]: - site type[^43] - network connectivity[^43] - PSTN access[^43] - dial plan requirements, including numbering, dialing habits and classes of restriction[^43] In Webex Calling, a Control Hub location can be assigned only 1 PSTN option: Cisco Calling Plan, Cloud Connected PSTN or on-premises local gateway[^42]. Cisco's Prepare guidance says to migrate users in groups and to keep dependent users together, for example users on shared lines, hunt groups, call pickup groups and intercom[^41]. The Migration Insights report HuntGroup_CallQueue_CallPark_CallPickUpGroups.csv identifies devices and users that should migrate together because of shared lines, hunt pilots, call queues, call park and call pickup groups[^20]. See also [Migrating a Unified CM dial plan to Webex Calling or Teams](https://warmtransfer.net/knowledge/dial-plan-migration). ## Phones, clients and voicemail The Migration Insights report DeviceEligibility.csv classifies IP phones, RoomOS devices, ATAs and third-party devices as follows[^15]: - Eligible[^15] - Eligible*, with reference to field notice FN74296[^15] - Ineligible or Unknown[^15] The report does not include Unified CM soft-client (ucmSoftClients) information[^21]. Firmware requirements for Cisco IP phones are as follows[^37][^46]: - Cisco 6800 series IP phones cannot be converted from Enterprise firmware to Multiplatform (MPP) firmware[^37]. - 7800 and 8800 phones need MPP firmware before transition to Webex Calling[^37]. - To use Cisco IP phones with Teams SIP Gateway, phones running Cisco enterprise firmware must first be converted to MPP firmware[^46]. A Teams user must have a phone number with PSTN calling enabled to use SIP Gateway[^48]. SIP Gateway does not publish presence for SIP devices, so presence-based routing does not work for call queue agents on SIP devices[^49]. Third-party devices on the Webex Calling supported list need approval from the Cisco account manager before they can be provisioned in Control Hub[^50]. Webex Calling cannot integrate with on-premises voicemail such as Unity Connection[^44]. Cisco says existing voicemail messages and greetings have no native migration path[^44]. See also [CUCM to Webex Calling migration](https://warmtransfer.net/knowledge/cucm-to-webex-calling). ## Analog, fax, paging and modems Cisco's Prepare assessment table lists paging, contact center, fax and analog devices as third-party integrations to assess before a Unified CM to Webex Calling migration[^38]. The Cisco analog telephone adapters listed as supported for Webex Calling are the ATA191 Multiplatform, ATA192 Multiplatform, VG400, VG410 and VG420[^51]. Webex Calling does not support modems[^53]. The usable port counts on AudioCodes hardware depend on the target platform[^52][^47]: - On Webex Calling the AudioCodes MP-124E supports only 17 ports because of mandatory encryption requirements[^52]. - With Teams SIP Gateway, AudioCodes MP114 ATAs expose 3 of 4 ports, MP118 ATAs 6 of 8 and the MP124-FXS 18 of 24, while the MP112, MP1288 and MP5xx models expose all ports[^47]. WarmTransfer's reading of the sources is that an analog inventory should count individual analog endpoints (ports and numbers) rather than ATA chassis, because the usable ports on the same family of AudioCodes hardware differ by target platform[^8]. With Teams SIP Gateway, the listed ATAs support only static emergency location, not dynamic location discovery[^45]. This applies to the Cisco ATA191/192-MPP, Poly ATA 400/402, OBi 300/302 and the AudioCodes MP-series[^45]. Microsoft documents the following for analog devices on Teams Direct Routing[^32][^29][^30][^31]: - Connecting analog devices requires an Analog Telephony Adapter, and the certified SBC vendor must support that adapter[^32]. - Microsoft treats an analog device as any device that can send DTMF digits to place a call, and names analog phones, fax machines and overhead pagers as examples[^29]. - Analog phones connected to an ATA cannot be found by search in Teams, so Teams users must dial the device's phone number manually[^30]. - Microsoft's analog example creates an online voice route for each analog device with that device's number pattern, or uses a single pattern that covers all the analog devices[^31]. See also [Analog gateways ATA and paging devices](https://warmtransfer.net/knowledge/analog-gateways-ata) and [Microsoft teams direct routing](https://warmtransfer.net/knowledge/microsoft-teams-direct-routing). ## Emergency calling data for US sites 47 CFR 9.16 sets these obligations for anyone who installs, manages or operates an MLTS in the US[^25][^28][^26][^27]: - **Direct dialing.** Under 47 CFR 9.16(b)(1), the MLTS must be configured so users can dial 911 directly, without a prefix or trunk-access code[^25]. - **Notification.** Under 47 CFR 9.16(b)(2), the MLTS must be configured to send a notification to a central location or another person when someone dials 911, if it can do so without hardware or software improvements[^28]. The notification must not delay the call[^28]. - **Fixed telephones.** Under 47 CFR 9.16(b)(3)(i), MLTS operators must convey dispatchable location for on-premises fixed telephones from January 6, 2021[^26]. - **Non-fixed and off-premises devices.** Under 47 CFR 9.16(b)(3)(ii)-(iii), dispatchable location for on-premises non-fixed devices and for off-premises devices applies from January 6, 2022 where technically feasible[^27]. Fallback location options apply where it is not technically feasible[^27]. We infer that a US PBX station inventory should record each station's physical location and whether the station is fixed, non-fixed or off-premises, since the dispatchable-location duties under 47 CFR 9.16(b)(3) depend on that split[^10]. For Teams dynamic emergency calling, admins must populate the Location Information Service with network identifiers (subnets, wireless access points, switches and ports), each mapped to an emergency location[^12]. The Teams LIS uses the first match in this order: wireless access point, Ethernet switch/port, Ethernet switch, subnet[^11]. ## Numbers and carrier accounts In a Teams Calling Plan port request, the billing telephone number must match the losing provider's records and any account freeze must be removed, or the port request is rejected[^34]. In a full Teams port request, every number associated with the BTN is ported, including the BTN itself, and the account with the current provider is closed[^35]. The Teams US and Canada porting wizard groups submitted numbers by account, service provider and type, and each group needs its own port request[^36]. For a Teams port, the organization name, account details and service address must match the current service provider's records exactly[^33]. WarmTransfer's reading of the sources is that every line on the carrier account, including analog, alarm, fax and modem lines that are not on the PBX, must be identified before a full port, because a full port closes the losing account[^9]. See also [Number porting and LNP workflows](https://warmtransfer.net/knowledge/number-porting). ## Other source platforms and coexistence In Control Hub, the PBX type list on the 'Migrate from BroadWorks & other PBX' card offers only BroadWorks and BroadCloud, despite the card's name[^5]. Users migrated with the BroadWorks/BroadCloud Webex Calling migration tool lose their call history, message history and personal settings such as speed dials[^6]. Once provisioning starts, the tool cannot pause or cancel it, and after provisioning completes a rollback can only be done manually[^4]. Zoom describes Bring Your Own PBX (BYOP) as connecting an on-premises PBX to Zoom Phone through configurable routing rules[^55]. According to Zoom, BYOP is most commonly used as an intermediate step before the on-premises system is decommissioned or put on standby[^55]. Zoom Phone endpoints open connections outbound to Zoom data centres, but BYOP SBCs need bi-directional connectivity[^54]. ## Applicability Applies to: Cisco Webex Calling, AudioCodes MP-124E, Microsoft Teams Phone, Cisco Unified Communications Manager, Zoom Phone, and AudioCodes MediaPack MP-1xx. Deployments: on-premises, multi-tenant, and dedicated instance. Sources checked 2026-10-14. The Migration Insights steps also apply to Dedicated Instance[^14]. The MAC address handling described above applies to FedRAMP (Webex for Government) organizations[^18]. The 47 CFR 9.16 obligations apply to MLTS in the US[^25]. The BTN and full-port rules apply to Teams Calling Plan port requests[^34][^35]. The number-grouping behaviour applies to the Teams US and Canada porting wizard[^36]. ## What remains uncertain Configuration export and usage-reporting tools for PBX platforms other than Unified CM, BroadWorks and BroadCloud are not covered by the sources below. DeviceEligibility.csv omits Unified CM soft-client information[^21]. How to inventory those soft clients by other means is not covered by the sources below. Whether Migration Insights reports can inform a migration to Microsoft Teams or Zoom Phone rather than Webex Calling is not covered by the sources below. ## Sources [^1]: The Unified CM BAT export's Check Dependency option selects dependent items only one level deep. Source: [Bulk Configure Changes with Import/Export Feature](https://www.cisco.com/c/en/us/support/docs/unified-communications/bulk-administration-tool/200596-Bulk-Configure-Changes-with-Import-Expor.html), Bulk Configure Changes with Import/Export Feature > Export Configuration. Checked 2026-10-14. [^2]: In a Unified CM BAT export, the User ID, User Pkid, Password and Pin fields in enduser.csv must not be modified, because the credential fields are stored encrypted. Source: [Bulk Configure Changes with Import/Export Feature](https://www.cisco.com/c/en/us/support/docs/unified-communications/bulk-administration-tool/200596-Bulk-Configure-Changes-with-Import-Expor.html), Bulk Configure Changes with Import/Export Feature > Export Configuration (enduser.csv caution). Checked 2026-10-14. [^3]: In Unified CM, the BAT export (Bulk Administration > Import/Export > Export) produces a .tar archive with one CSV per exported item plus a header file listing the source server, export time and contents. The archive is downloaded from Bulk Administration > Upload/Download Files. Source: [Bulk Configure Changes with Import/Export Feature](https://www.cisco.com/c/en/us/support/docs/unified-communications/bulk-administration-tool/200596-Bulk-Configure-Changes-with-Import-Expor.html), Bulk Configure Changes with Import/Export Feature > Export Configuration. Checked 2026-10-14. [^4]: Once provisioning starts, the BroadWorks/BroadCloud Webex Calling migration tool cannot pause or cancel it, and after provisioning completes a rollback can only be done manually. Source: [Migration from BroadWorks and BroadCloud to Webex Calling](https://help.webex.com/en-us/article/n1ku0vfb), Migration from BroadWorks and BroadCloud > provisioning step. Checked 2026-10-14. [^5]: In Control Hub, the PBX type list on the 'Migrate from BroadWorks & other PBX' card offers only BroadWorks and BroadCloud, despite the card's name. Source: [Migration from BroadWorks and BroadCloud to Webex Calling](https://help.webex.com/en-us/article/n1ku0vfb), Migration from BroadWorks and BroadCloud to Webex Calling > Select PBX type step. Checked 2026-10-14. [^6]: Users migrated with the BroadWorks/BroadCloud Webex Calling migration tool lose their call history, message history and personal settings such as speed dials. Source: [Migration from BroadWorks and BroadCloud to Webex Calling](https://help.webex.com/en-us/article/n1ku0vfb), Migration from BroadWorks and BroadCloud > post-migration impacts. Checked 2026-10-14. [^7]: A configuration export alone (such as a Unified CM BAT .tar) shows what is configured but not what is used, so a usage source such as CDRs is needed to find routing and features that are live but undocumented (inferred). Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare > Features and feature usage; with Migration Insights CDR upload section. Checked 2026-10-14. [^8]: An analog inventory should count individual analog endpoints (ports and numbers), not ATA chassis, because the usable ports on the same family of AudioCodes hardware differ by target platform (inferred). Source: [Plan SIP Gateway](https://learn.microsoft.com/en-us/microsoftteams/devices/sip-gateway-plan), Plan SIP Gateway > Compatible devices > AudioCodes rows; compare Webex supported-devices MP-124E note. Checked 2026-10-14. [^9]: Before a full port, every line on the carrier account (including analog, alarm, fax and modem lines that are not on the PBX) needs to be identified, because a full port closes the losing account (inferred). Source: [Transfer phone numbers to Microsoft Teams](https://learn.microsoft.com/en-us/microsoftteams/phone-number-calling-plans/transfer-phone-numbers-to-teams), Transfer phone numbers to Microsoft Teams > Billing telephone number (BTN). Checked 2026-10-14. [^10]: For US sites, a PBX station inventory should record each station's physical location and whether it is fixed, non-fixed or off-premises, since dispatchable-location duties under 47 CFR 9.16(b)(3) depend on that split (inferred). Source: [47 CFR 9.16 General obligations for 911 dialing, notification, and location (MLTS), 2024 annual edition](https://www.govinfo.gov/content/pkg/CFR-2024-title47-vol1/xml/CFR-2024-title47-vol1-sec9-16.xml), 47 CFR 9.16(b)(3)(i)-(iii). Checked 2026-10-14. [^11]: The Teams LIS matches a client's location using the first match in this order: wireless access point, Ethernet switch/port, Ethernet switch, subnet. Source: [Configure dynamic emergency calling](https://learn.microsoft.com/en-us/microsoftteams/configure-dynamic-emergency-calling), Configure dynamic emergency calling > Plan for emergency calling, step 2. Checked 2026-10-14. [^12]: For Teams dynamic emergency calling, admins must populate the Location Information Service with network identifiers (subnets, wireless access points, switches and ports), each mapped to an emergency location. Source: [Configure dynamic emergency calling](https://learn.microsoft.com/en-us/microsoftteams/configure-dynamic-emergency-calling), Configure dynamic emergency calling > Configure Location Information Service. Checked 2026-10-14. [^13]: Migration Insights accepts CDR files up to 2 GB, uploaded as .gzip after they are run through Cisco's CDR Preprocessing script. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > CDR upload section. Checked 2026-10-14. [^14]: Migration Insights is opened in Control Hub from Services > Updates & Migrations, on the Migration Insights card in the Unified CM upgrade utilities section, and the same steps apply to Dedicated Instance. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > generate report steps; Prerequisites > Dedicated Instance note. Checked 2026-10-14. [^15]: The Migration Insights DeviceEligibility.csv report classifies IP phones, RoomOS devices, ATAs and third-party devices as Eligible, Eligible* (with reference to field notice FN74296), or Ineligible or Unknown. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > report contents > DeviceEligibility.csv. Checked 2026-10-14. [^16]: Migration Insights DidUsageReport.csv reports the usage of both assigned and unassigned DIDs. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > report contents > DidUsageReport.csv. Checked 2026-10-14. [^17]: Migration Insights FeatureUsageWithLastUsageDateReport.csv gives usage counts and last-use dates for hunt pilots and call queues, taken from uploaded CDRs. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > report contents > FeatureUsageWithLastUsageDateReport.csv. Checked 2026-10-14. [^18]: For FedRAMP (Webex for Government) organizations, the commercial device eligibility check in Migration Insights sends device MAC addresses to Cisco's corporate network. Organizations that do not want this can use the separate FedRAMP device migration process. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > Prerequisites > FedRAMP note. Checked 2026-10-14. [^19]: Webex Calling Migration Insights takes Unified CM data as a .tar file generated with the Unified CM Bulk Administration Tool, uploaded in Control Hub. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > generate report steps (collect Unified CM details / upload .tar). Checked 2026-10-14. [^20]: Migration Insights HuntGroup_CallQueue_CallPark_CallPickUpGroups.csv identifies devices and users that should migrate together because of shared lines, hunt pilots, call queues, call park and call pickup groups. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > report contents > HuntGroup_CallQueue_CallPark_CallPickUpGroups.csv. Checked 2026-10-14. [^21]: The Migration Insights DeviceEligibility.csv report does not include Unified CM soft-client (ucmSoftClients) information. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > report contents > DeviceEligibility.csv note. Checked 2026-10-14. [^22]: Cisco states that Migration Insights deletes the uploaded tar file and related data after it generates the reports, and keeps no user data beyond report generation. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > data handling statement. Checked 2026-10-14. [^23]: The Migration Insights upload limit for the Unified CM .tar file is 350 MB. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > upload step. Checked 2026-10-14. [^24]: The Migration Insights usage-based eligibility report marks a device Unknown when its CDRs show features Webex Calling does not support, and the article says to contact Cisco TAC in that case. Source: [Migration insights](https://help.webex.com/en-us/article/svoi86/Migration-Insights), Migration Insights > report contents > FeatureUsageBasedDeviceEligibilityReport.csv. Checked 2026-10-14. [^25]: Under 47 CFR 9.16(b)(1), anyone who installs, manages or operates an MLTS in the US must configure it so users can dial 911 directly, without a prefix or trunk-access code. Source: [47 CFR 9.16 General obligations for 911 dialing, notification, and location (MLTS), 2024 annual edition](https://www.govinfo.gov/content/pkg/CFR-2024-title47-vol1/xml/CFR-2024-title47-vol1-sec9-16.xml), 47 CFR 9.16(b)(1). Checked 2026-10-14. [^26]: Under 47 CFR 9.16(b)(3)(i), MLTS operators must convey dispatchable location for on-premises fixed telephones from January 6, 2021. Source: [47 CFR 9.16 General obligations for 911 dialing, notification, and location (MLTS), 2024 annual edition](https://www.govinfo.gov/content/pkg/CFR-2024-title47-vol1/xml/CFR-2024-title47-vol1-sec9-16.xml), 47 CFR 9.16(b)(3)(i). Checked 2026-10-14. [^27]: Under 47 CFR 9.16(b)(3)(ii)-(iii), dispatchable location for on-premises non-fixed devices and for off-premises devices applies from January 6, 2022 where technically feasible, with fallback location options where it is not. Source: [47 CFR 9.16 General obligations for 911 dialing, notification, and location (MLTS), 2024 annual edition](https://www.govinfo.gov/content/pkg/CFR-2024-title47-vol1/xml/CFR-2024-title47-vol1-sec9-16.xml), 47 CFR 9.16(b)(3)(ii) and (iii). Checked 2026-10-14. [^28]: Under 47 CFR 9.16(b)(2), an MLTS must be configured to send a notification to a central location or another person when someone dials 911, if it can do so without hardware or software improvements, and the notification must not delay the call. Source: [47 CFR 9.16 General obligations for 911 dialing, notification, and location (MLTS), 2024 annual edition](https://www.govinfo.gov/content/pkg/CFR-2024-title47-vol1/xml/CFR-2024-title47-vol1-sec9-16.xml), 47 CFR 9.16(b)(2)(i)-(iii). Checked 2026-10-14. [^29]: For Teams Direct Routing, Microsoft treats an analog device as any device that can send DTMF digits to place a call, and names analog phones, fax machines and overhead pagers as examples. Source: [Direct Routing - Connecting analog devices](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-analog-devices), Direct Routing - Connecting analog devices > Considerations, bullet 1. Checked 2026-10-14. [^30]: Analog phones connected to an ATA cannot be found by search in Teams, so Teams users must dial the device's phone number manually. Source: [Direct Routing - Connecting analog devices](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-analog-devices), Direct Routing - Connecting analog devices > Considerations, bullet 2. Checked 2026-10-14. [^31]: Microsoft's Direct Routing analog example creates an online voice route for each analog device with that device's number pattern, or uses a single pattern that covers the analog devices. Source: [Direct Routing - Connecting analog devices](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-analog-devices), Direct Routing - Connecting analog devices > Step 7: Create a voice route for an analog device. Checked 2026-10-14. [^32]: To connect analog devices to Teams Direct Routing, an Analog Telephony Adapter is required, and the certified SBC vendor must support that adapter. Source: [Direct Routing - Connecting analog devices](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-analog-devices), Direct Routing - Connecting analog devices > introduction. Checked 2026-10-14. [^33]: For a Teams port, the organization name, account details and service address must match the current service provider's records exactly. Source: [Transfer phone numbers to Microsoft Teams](https://learn.microsoft.com/en-us/microsoftteams/phone-number-calling-plans/transfer-phone-numbers-to-teams), Transfer phone numbers to Microsoft Teams > Porting wizard - All regions > Add account information (note and item 6). Checked 2026-10-14. [^34]: In a Teams Calling Plan port request, the billing telephone number must match the losing provider's records and any account freeze must be removed, or the port request is rejected. Source: [Transfer phone numbers to Microsoft Teams](https://learn.microsoft.com/en-us/microsoftteams/phone-number-calling-plans/transfer-phone-numbers-to-teams), Transfer phone numbers to Microsoft Teams > Porting wizard - New (U.S. & Canada) > Billing telephone number (BTN). Checked 2026-10-14. [^35]: In a full Teams port request, every number associated with the BTN is ported, including the BTN itself, and the account with the current provider is closed. Source: [Transfer phone numbers to Microsoft Teams](https://learn.microsoft.com/en-us/microsoftteams/phone-number-calling-plans/transfer-phone-numbers-to-teams), Transfer phone numbers to Microsoft Teams > Porting wizard - New (U.S. & Canada) > Billing telephone number (BTN). Checked 2026-10-14. [^36]: The Teams US and Canada porting wizard groups submitted numbers by account, service provider and type, and each group needs its own port request. Source: [Transfer phone numbers to Microsoft Teams](https://learn.microsoft.com/en-us/microsoftteams/phone-number-calling-plans/transfer-phone-numbers-to-teams), Transfer phone numbers to Microsoft Teams > Porting wizard - New (U.S. & Canada) > Phone numbers, step 2. Checked 2026-10-14. [^37]: Cisco 6800 series IP phones cannot be converted from Enterprise firmware to Multiplatform (MPP) firmware, whereas 7800 and 8800 phones need MPP firmware before transition to Webex Calling. Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare > Devices and clients. Checked 2026-10-14. [^38]: Cisco's Prepare assessment table lists paging, contact center, fax and analog devices as third-party integrations to assess before a Unified CM to Webex Calling migration. Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare > Table 1 > third-party integrations row. Checked 2026-10-14. [^39]: Cisco's UCM-to-Webex Calling Prepare guidance calls assessing the current on-premises environment and deployment a key planning activity, covering licensing, locations, devices, users, PSTN, features, integrations and network readiness. Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare to migrate from Unified CM to Webex Calling > assess current environment (Table 1). Checked 2026-10-14. [^40]: Cisco advises identifying which Unified CM features are configured and then assessing which are actually used, using Migration Insights, CDR data and Cloud-Connected UC analytics. Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare > Features and feature usage. Checked 2026-10-14. [^41]: Cisco's Prepare guidance says to migrate users in groups and keep dependent users together, for example users on shared lines, hunt groups, call pickup groups and intercom. Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare > Users. Checked 2026-10-14. [^42]: In Webex Calling, a Control Hub location can be assigned only one PSTN option (Cisco Calling Plan, Cloud Connected PSTN or on-premises local gateway). Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare > PSTN connectivity. Checked 2026-10-14. [^43]: Cisco's Prepare guidance has the per-site inventory record site type, network connectivity, PSTN access and dial plan requirements, including numbering, dialing habits and classes of restriction. Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare > Locations and sites. Checked 2026-10-14. [^44]: Webex Calling cannot integrate with on-premises voicemail such as Unity Connection, and Cisco says existing voicemail messages and greetings have no native migration path. Source: [Prepare to migrate from Unified CM to Webex Calling](https://help.webex.com/en-us/article/4yz2zd/Prepare-to-migrate-from-Unified-CM-to-Webex-Calling), Prepare > Cisco integrations (Unity Connection, UCCX, UCCE). Checked 2026-10-14. [^45]: With Teams SIP Gateway, the listed ATAs (including Cisco ATA191/192-MPP, Poly ATA 400/402 and OBi 300/302, and the AudioCodes MP-series) support only static emergency location, not dynamic location discovery. Source: [Plan SIP Gateway](https://learn.microsoft.com/en-us/microsoftteams/devices/sip-gateway-plan), Plan SIP Gateway > Compatible devices > footnote 3 markers on ATA rows. Checked 2026-10-14. [^46]: To use Cisco IP phones with Teams SIP Gateway, phones running Cisco enterprise firmware must first be converted to multiplatform (MPP) firmware. Source: [Plan SIP Gateway](https://learn.microsoft.com/en-us/microsoftteams/devices/sip-gateway-plan), Plan SIP Gateway > Compatible devices > Cisco row remarks. Checked 2026-10-14. [^47]: With Teams SIP Gateway, AudioCodes MP114 ATAs expose 3 of 4 ports, MP118 ATAs 6 of 8 and the MP124-FXS 18 of 24, while the MP112, MP1288 and MP5xx models expose all ports. Source: [Plan SIP Gateway](https://learn.microsoft.com/en-us/microsoftteams/devices/sip-gateway-plan), Plan SIP Gateway > Compatible devices > AudioCodes rows (Links column). Checked 2026-10-14. [^48]: To use Teams SIP Gateway, a Teams user must have a phone number with PSTN calling enabled. Source: [Plan SIP Gateway](https://learn.microsoft.com/en-us/microsoftteams/devices/sip-gateway-plan), Plan SIP Gateway > Requirements to use SIP Gateway. Checked 2026-10-14. [^49]: SIP Gateway does not publish presence for SIP devices, so presence-based routing does not work for SIP-device call queue agents. Source: [Plan SIP Gateway](https://learn.microsoft.com/en-us/microsoftteams/devices/sip-gateway-plan), Plan SIP Gateway > Benefits of SIP Gateway > Call Queues and voice apps support. Checked 2026-10-14. [^50]: Third-party devices on the Webex Calling supported list need approval from the Cisco account manager before they can be provisioned in Control Hub. Source: [Supported devices for Webex Calling](https://help.webex.com/en-us/article/qkwt4j/Supported-Devices-for-Webex-Calling), Supported devices for Webex Calling > List of supported third-party devices. Checked 2026-10-14. [^51]: The Cisco analog telephone adapters listed as supported for Webex Calling are the ATA191 Multiplatform, ATA192 Multiplatform, VG400, VG410 and VG420. Source: [Supported devices for Webex Calling](https://help.webex.com/en-us/article/qkwt4j/Supported-Devices-for-Webex-Calling), Supported devices for Webex Calling > Analog Telephone Adapters. Checked 2026-10-14. [^52]: On Webex Calling the AudioCodes MP-124E supports only 17 ports because of mandatory encryption requirements. Source: [Supported devices for Webex Calling](https://help.webex.com/en-us/article/qkwt4j/Supported-Devices-for-Webex-Calling), Supported devices for Webex Calling > third-party devices > AudioCodes MP-1xx. Checked 2026-10-14. [^53]: Webex Calling does not support modems. Source: [Supported devices for Webex Calling](https://help.webex.com/en-us/article/qkwt4j/Supported-Devices-for-Webex-Calling), Supported devices for Webex Calling > Limitations. Checked 2026-10-14. [^54]: Zoom Phone endpoints open connections outbound to Zoom data centres, but BYOP SBCs need bi-directional connectivity. Source: [Migration Strategies (Zoom Phone Bluepaper)](https://library.zoom.com/zoom-workplace/zoom-phone/zoom-phone-bluepaper/migration-strategies), Zoom Phone blue paper > Migration Strategies > BYOP network note. Checked 2026-10-14. [^55]: Zoom describes Bring Your Own PBX (BYOP) as connecting an on-premises PBX to Zoom Phone through configurable routing rules, most commonly as an intermediate step before the on-premises system is decommissioned or put on standby. Source: [Migration Strategies (Zoom Phone Bluepaper)](https://library.zoom.com/zoom-workplace/zoom-phone/zoom-phone-bluepaper/migration-strategies), Zoom Phone blue paper > Migration Strategies > BYOP section. Checked 2026-10-14.