Mixing Calling Plan and Direct Routing connectivity for the same user is optional, but could be useful, for example, when the user is assigned a Microsoft Calling Plan but wants to route some calls via SBC. One of the most common scenarios are calls to third-party PBXs. With third-party PBXs, all calls, except calls to the phones connected to that PBXs, are routed via Microsoft Calling Plan; but calls to the phones connected to third-party PBXs go to the SBC, therefore stay within the enterprise network and not to the PSTN.
Migrate SFB clients to Teams Client