Back in 2017 at Ignite in Orlando I was watching lots of news regarding to this. When I got back in Norway I started to work an product where customers can bring their own telco to Teams. This we call Telephony in Teams.
The solutions is up and running i Azure West Europe zone 1, 2, 3 with SBC from AudioCodes. The solutions is 100% Cloud and we have also done integration with Genesys PureCloud and Telia switchboard. For the PureCloud who use WebRTC we can answer the call using the toaster from Teams.
We have delivered Sip trunks from, Telia, Telenor, Broadnet, IPCO, Voxbone and many more. The customer can bring their own telco agreement to our solutions. This is 100% telco independent (globally). We had the first customer live in October 2018 on this service. We does also recording who is required from the bank and financial industri and host the recording files in Norway.
You can read more about it here: https://blinq.no/summetone-i-teams/
This post is in norwegian but translate with if you are not good in norwegian. :-) This is all deliveried by a MicroSoft Gold Partner blinQ AS.